Heat Exchanger World

Selecting Home Heating System

2011-08-26T11:17:00.000-07:00

There are various heating systems that can be practically installed in a residential homes located in four climate countries such as North America and Europe. Hence, you need to know which one to opt for. There are basically two types of heating systems for house. You can choose to (1) install a central heating system run by gas, or (2) mount a heater in every single room. The operation of each heating system mentioned previously is different.

The central heating system is simpler and requires less work. You only need to change the amount or intensity of heat by simply turning its control knob. The latter heating system could be quite dreary. For this, there is a need for you to control all heaters in each of the rooms in the house. By comparison, the individual heating system is much hassle to maintain.

In general, you will require a furnace or boiler, that normally be placed below the house. Via this, warm air is pumped through the air ducts that enable the heat to warm the entire home. Another option is to install a radiator for a room, almost similar to the radiator in the car engine. In this case, heated water will be circulated within the house to create a warmer environment. However, this option is less popular compared to the central heating system.

Controlling the temperature in the house is crucially important. To be able to control the temperature, a thermostat is needed. Having these controls, it is easier to adjust or manipulate the heat in your home. In the case of homes that do not use a central heating system, a baseboard heaters or floor heaters, which run on electric current can be also applied. Bear in mind, powering the heating system with electricity will result to you paying a huge sum of electricity bill at the end of the month. So, bottom line, you may want to choose the most economical heating system and at the same time the pleasure of soothing temperature.

Image source: ehow.com/info_8380230_home-heating-system-types.html

How Air Conditioners & Heat Exchangers Work

2010-02-07T09:44:00.000-08:00

Check out this video. It shows how Air Conditioners & Heat Exchangers Work. Very interesting and from it, you can have better comprehension on all the heat transfer process involving these two types of unit operations.

HRS Unicus® Dynamic Heat Exchanger Animation

2010-02-07T09:42:00.000-08:00

Virtual animation of how Unicus® scraped surface dynamic heat exchanger works and is assembled.

Hydronic Heat Exchanger - The 3 Basic Types of Hydronic Heating Systems You Should Know

2010-02-07T09:38:00.000-08:00

Hydronic heat exchangers or "steam" systems have been around with us since the 1800's at the dawn of the Industrial Age. Steam engines changed the world of transportation almost overnight and steam heat or hydronic heat exchanger systems did the same thing residential and commercial heating.

Almost at the same time that the first steam boilers were made power the great railroad engines, manufacturing mills and cargo ships, steam heat found its way into the home. This is not an unnatural course of events considering the amount of heat that can be put out by steam; as anyone who has ever sat for long in a moist sauna can testify to.

The Theory behind Hydronic Heating Systems

These systems are actually very simple. The most common hydronic heat exchanger consists of three main components: the boiler (the heating source), the piping array and the heat exchangers (which transfer the heat from the water into warmth for the room.)

The process goes like this: water is heated and then either turned into steam or very near to boiling and is then piped to radiators (located through-out the house) or to thermal mass floorings (which absorbs the heat and slowly releases it into the room).

The 3 types of fuel sources for a hydronic heat exchanger are electric, gas or oil-fired boilers. Boilers can be made from cast-iron, stainless steel or copper. While there are different ways that each of these boilers are constructed, each with their own advantages and disadvantages, the main idea to understand that is each boiler is basically heating a closed-water system.

This means that any chronic lost of fluid can cause a problem. This is why the type of piping array becomes critically important to the overall system.

The Three Basic Hydronic Heat Exchanger Types

As you may have guessed by now, hydronic heat exchangers are most often classified by their piping arrangements:

o One-pipe or single pipe
o Two pipe
o Loop series

The oldest of hydronic heat exchanger designs is the one-pipe array. A single pipe carries steam from the boiler to every radiator in the structure. The single-pipe has a layout made so that eventually gravity will pull the condensed water in the piping back into the boiler tank. A two-pipe system uses a second return pipe instead of gravity-induced flow to bring water back to the holding tanks.

Both single and two pipe systems were designed for steam-based heat exchangers but most modern units use hot water in a loop series of pipes as the heat conductors. This type of system offers a slimmer wall-mount, stainless steel heat transfer unit and has better energy-efficient water to air heat transfer rates.

Another advantage of this kind of hydronic heating is that if properly equipped will heat water for domestic uses like cooking, washing or bathing as well as water for external uses such as swimming pools, spas, hot tubs, garages or greenhouses. Plus looped pipe hydronic heat exchangers will not only provide heat in the winter months but can be used to circulate chilled water in the summer months to aid in overall cooling.

So as you can see modern hydronic heat exchanger systems can not warm you and your family in those cold winter months but also provide a low cost method of central air cooling as well.

After a successful life in trading, importing and exports, Rupert now spends his time writing freelance articles for many well-known publications, as well as various educational institutions. For more of Rupert's articles regarding hydronic heat systems, please visit http://www.hydronic-heating-systems.com/

Importance of Keeping Heat Exchanger Clean

2009-08-08T19:20:00.000-07:00

The heat exchanger air-water purification is an absolute necessity so that the system of production runs. If your heat exchanger will not be as clean as it should be, he is unable to properly operate and exchange of heat, could not take place. This leads to significant problems in the line if it is not treated within a short time. However, with the cleaning alone is not sufficient to keep everything in perfect condition.

An air-water heat exchanger is very specialized devices intended for use when the air or in the air, the temperatures are higher than 130 degrees Fahrenheit. Air conditioning industry is not the machine to cool when the ambient temperature is at this level, since the refrigerant compressor of its production to about 150 degrees Fahrenheit, and there is too little difference between the two temperatures for the coolant to his job. In such cases, the air-water heat exchanger in question. They bring in the chamber in the courtyard below the temperature of the air, so that the device is not working correctly.

Basically, a heat exchanger air water cleaning is simply to ensure that both air and water to a portion of the thermal processes of your system are clean. For example, if the mechanism of the system brings the air is a cooling tower, you must bear in mind when he brings the air in the system, the debris, which is not in the air in the system with him. These deposits may be in the system, the establishment in her, and limited the operation - and possibly causing a malfunction, and even heavier. So, quite simply your own system seems to heat the solution to this problem.

However, the ratings are compared, what the adoption of a cold tablet, if you have a cold, and rightly so. Even if the cleaning of the heat exchanger of the system ensures that they are free of everything, leading to problems, whether it is doing nothing to prevent the problem does not occur, particularly in areas where there is a lot of scrap , potentially leading to a kind of jam. In this sense, the cleaning is not enough.

The ultimate solution would be an excellent technology Filtersystem keep residue in the system, primarily, and cleaned with care.

So, make the installation of filters and the technology of filtration and devout your water air heat exchanger for cleaning your entire system to function optimally.

Gas Quench with External Heat Exchange Vacuum Furnaces

2009-07-11T07:46:00.000-07:00

Looking for a multi-purpose vacuum furnaces?

This versatile series of multi-purpose vacuum furnaces offers a wide variety of sizes and configurations, including horizontal or vertical designs. As users have a choice of hot zones, pumping systems and gas cooling options, the MetalMaster™ is ideal for almost any heat treating, brazing or other thermal processing application. The gas quench system features a specially engineered heat exchanger and turbine blower designed to optimize gas flow for more efficient cooling. In addition to Ipsen's standard computer control systems, MetalMaster™ furnaces may be ordered with other high-productivity options, including specialized instrumentation, increased pumping capability, and material handling systems. Standard features include:

Specially engineered external heat exchanger and gas blower
Choice of hot zone insulation packages
360° gas cooling nozzles and heating elements for precise control
Selection of value-added options

The article is adopted from azom.com.

Plate Heat Exchangers - Design, Advantages and Disadvantages

2009-06-24T06:31:00.000-07:00

Plate heat exchangers are obviously types of heat exchangers. It functions by transferring the heat from one fluid to another through the use of metal plates. Comparing it with conventional heat exchangers, these ones are favored specifically because the fluids work on larger surface areas and are capable of dispersing to the metal plates. Simply put, the procedure enables proper facilitation of heat transfer as it speeds up the changes in temperature occurring during the process.

Knowing more about the concept of plate heat exchangers involves looking at the design of the tool as well as setting apart the advantages from its disadvantages. Basically, a heat exchanger uses pipes in order to cool or heat a fluid through the process of transferring it to another fluid. The pipes' walls are often made either out of metal or other substances known to be of high thermal conduction capabilities. This is to ensure that the transfer of heat from one fluid to another will be properly facilitated. Another coating is found outside the pipe walls, now made of plastic with thermal insulation to suppress the heat from coming out of the exchanger.

Design of plate heat exchangers

From the conventional design of heat exchangers, a plate heat exchanger is said to be more of a specialized one. The design was made to construe with its purposes of heat transfer for two types of fluids. For the heat exchanging process, semi-welded, brazed or welded exchangers are used. Instead of making use of a regular pipe, two chambers are used and are separated by the so-called corrugated metal plate.

The plate is designed out of stainless steel. This material has the ability to withstand corrosion and high temperature while it is also noted for its durability and strength. In between the plates, rubber sealing gaskets are placed.

A look at its advantages and disadvantages

The advantages of this type of heat exchangers are seen through its compactness, flexibility and ease of cleaning. Its compactness can be attributed to the fact that the entire output does not require a large floor space. Its flexibility is seen with its ability to cope with requirements of different types of fluids. The plates are removable thus making it easy to clean. If replacement is needed, the plates may be removed conveniently as well.

The main disadvantages of plate heat exchangers are classified into three. First, long gaskets are needed. Second, leakage is probable. And lastly, operation costs as well as investment should also form part of the consideration.

Visit the American Industrial Directory to find leading manufacturers of industrial equipment, machinery and supplies based in the U.S., Canada and Mexico offering a wide range of plate heat exchangers and other products and solutions for the global industrial marketplace.

Marine Diesel Engine Maintenance - Engine Cooling

2009-06-04T08:26:00.000-07:00

Understanding the marine diesel engine cooling system is a necessary part of marine diesel engine maintenance.

Raw Water Cooling

Flexible impeller pumps provide an efficient solution to most raw water pumping needs. The primary advantage of a flexible impeller pump is that it is self-priming, which means that when the vanes of the impeller are depressed and rebound, they create their own vacuum, drawing fluid into the pump. A dry pump can lift water up to as much as three meters. Thus a flexible impeller pump being used for engine cooling does not need to be manually primed or located below the water line. An added feature of a flexible impeller pump is that it can pass fairly large solids without clogging or damaging the pump. This reduces the need for filtration of incoming fluids.

For general or fresh water applications, a standard long lasting neoprene rubber impeller is used.

A general feature of all flexible impeller pumps is that they cannot be permitted to run dry for more than 30 seconds. Both the impeller and the seals require water for lubrication and will soon burn out if run dry. Parts that start to show wear are easily replaceable and service kits are readily available for most models.

Fresh Water Cooling

For circulation of the internal, closed, fresh water circuit of the cooling system it is common to use a flexible rubber pump if it is located on the cold side of the system (max. 55°C). Other types of belt-driven centrifugal pumps are also used. The closed circuit normally transfers heat from the engine to the heat exchanger. The liquid used is water and anti-freeze.

Cooling Capacity

The required output of the cooling pump is related to engine type and size, not to the size of the heat exchanger and exhaust system. This is true for both raw water as well as fresh water handling systems.

Temperature Regulators (Thermostats)

Thermostats are usually placed in the outlet at the top of the cylinder head to prevent the coolant from moving to the header tank until the marine engine has nearly reached operating temperature.

There are different types of thermostats, the most common being the wax pellet type. The capsule on the lower part of the thermostat has a mixture of wax and copper (to increase the thermal conductivity) sealed in it. As the coolant temperature increases, the wax expands and forces a rod to open the poppet valve at the top of the thermostat, which allows the coolant to circulate.

Cooling system checks

To test your thermostat, boil a pot of water and drop in the thermostat. (The water must be 100°C--the thermostat usually opens at 85°C.) If the thermostat opens it is okay. If it doesn't open, replace or clean carefully as they can become sticky with deposits. Yanmar thermostats can and should be regularly serviced. Some thermostats cannot be serviced.
If the thermostat doesn't work, do not remove it and run the engine without it, as the engine will run cold and tight. You can drill a series of 1/4Ë holes to give equivalent flow to an open thermostat. This will get you home, but you must then replace it. Be careful not to fit thermostat upside down.
Thermostat housings often corrode and need to be replaced. Some can be fabricated.
The cooling system should be checked after 100 hours running, or at least once each season, for leakage, deposits, etc.
The thermostat can be taken out of the housing on the front of the engine.
The heat exchanger core should be removed bi-annually for cleaning and inspection.
Many heat exchangers are fitted with anodes to protect the expensive core. Check regularly.
Check all hoses and clamps regularly.

Replacing the sea-water pump impeller

The pump impeller is made of neoprene rubber and this can be damaged in the case of water deficiency if, for example, the sea-water intake should be blocked. The pump impeller is changed as follows:

Remove the cover from the sea-water pump. Note that there is the risk of water getting into the boat. With the help of two screwdrivers pull the shaft with the pump impeller out of the housing as far as necessary to reach the bolt retaining the impeller. Place some kind of protection under the screwdrivers in order not to damage the impeller housing. Alternatively, using channel-lock pliers, slide jaws between blades of impeller, rotate and withdraw.
Pull the impeller off the shaft. Clean the inside of the pump housing and fit the new impeller. Always have a spare impeller on board.
Check that the pump coupling is not damaged, by trying to turn the pump impeller. Fit the cover with the original gasket, which has the right thickness.

Check out the impeller trouble shooting guide to discover how to repair and replace a sea water pump impeller. Did you know that if you understand the basics of marine diesel engine maintenance you can service your own marine engine and save on maintenance costs? Every boat owner should have at least a minimum understanding of their marine engine. Keep your family safe on the water, find out how to service your marine diesel engine yourself and know that it is properly maintained. Learn which spare parts you absolutely must carry on board your boat and discover how to make emergency boat repairs on the water.

USB Heat - Cost-Effective Energy-Efficient Infrared Heat

2009-04-27T06:18:00.000-07:00

Do your hands get cold when you are using the computer? Not all people have cold hands, but many of us do. Cold hands may be the cause of poor circulation or arthritis. Whatever it is, when the chill hits, we feel it to the bones. Especially, when we are sitting still inactive at the computer with only our fingers doing the surfing.

Instead of cranking up the furnace for heat, there are economical ways to use the computer to generate warm heat for you while you are using the computer. Does your mouse hand get cold? Do your keyboard hands and fingers get cold? If so, USB infrared heat computer accessories may be the answer.

For a cost-effective approach to heat, use the computer to generate warmth for you. Plug an USB warm mouse into a socket and within a few minutes the mouse is warm and heat is delivered to your mouse hand. For keyboard hands, wrists and arms, plug an USB heated keyboard pad into a socket and rest your keyboard hands and wrists on a warm, soft, ergonomically supported pad in front of the keyboard.

There's more. An USB heated mouse pad creates a warm smooth soothing surface for your mouse and mouse hand. The warm mouse pad definitely takes the cold edge off a cold pad's surface. And, if you've ever crawled under the covers of an electric blanket on a cold winter's night, you'll appreciate the warmth of the USB heated mouse hand warmer blanket. It's a fleece mini-electric blanket pouch to hold the warm mouse and warm mouse pad.

Together the USB heated ergonomic computer accessories serve a wonderful cost-effective and energy-efficient purpose and when used together, they create the perfect warm, mouse hand environment.

The next time you are sitting at the computer and you feel a chill, think about the warming devices available to keep you warm using the heat from the computer. It will save you money and provide a convenient source of warmth.

Anna Miller: ValueRays® USB Heated Ergonomic Computer Accessories -- http://IGMproducts.com & http://Warm-Mouse-Heated-Keyboard.com

Does a Dirty Furnace Filter Impact Equipment Performance?

2009-04-03T08:06:00.000-07:00

Unfortunately one of the most often neglected maintenance tasks for residential heating and air conditioning systems is changing the furnace filter. A furnace filter is an extremely important component of any air conditioner or furnace.

Many people use the cheap disposable fibreglass furnace filters thinking they are getting good value for their money. The reality is that these filters are next to useless because they don't remove enough dust from the air to make much of a difference.

There is greater value in using one of the more efficient varieties of furnace filter available and there are many to choose from, beginning with the most commonly used pleated furnace filter to some of the lesser known specialty filters commonly used in many homes.

Why is the furnace filter so important?
There are several very important things that happen when people don't change their furnace filter or air conditioner filter. You often hear that not changing your air conditioner filter or furnace filter will cause problems.

What really happens?

Air Conditioner Filter

Reduced refrigerant operating pressures within the air conditioner which can cause the evaporator coil to ice up.
Reduced cooling capacity which results in longer run times and higher energy costs.
Poor air circulation throughout your home resulting in some spaces not being cooled properly

Furnace Filter

Reduced air flow across the heat exchanger resulting in higher heat exchanger operating temperatures. This can result in cracked heat exchangers causing Co to leak into the space being heated.
Increased run times due to lower air flow. This results in higher fuel costs because it takes longer to heat the space. In electric forced air furnaces the result is the same except your power bill will be higher.

A common belief is that the blower fan also has to work harder when the furnace filter is dirty but this claim is only made by people who don't really understand the operating characteristics of a centrifugal fan.

How often should you change your furnace filter?
To ensure that your furnace or air conditioner continues to operate at maximum efficiency it is very important to replace or clean your air filter at least every three months for one and two inch filters. Four inch filters can often be left in the system longer depending on the filter efficiency and several other factors.

Which replacement furnace filter is the best?
Selecting the best furnace filter is not an easy thing to do because there are so many variables to consider. There are filters to meet virtually every need. Allergy sufferers may require a very efficient filter, while a person who has no allergies only requires a moderately efficient filter. Maybe you don't have allergies but you hate dusting and that is what guides you in making your decision.

To make things even more complicated, there are even duct mounted air purifiers that you can use in conjunction with a your furnace filter. These help to purify the air even further.

For articles to help you determine which replacement furnace filter is best for your needs visit us at FurnaceFilterCare.com. Comment on our blog, have your questions answered or just let us share twenty years of industry experience.

Swimming Pool and Spa Electric Heat Pumps

2009-03-25T07:13:00.000-07:00

Swimming in a cold pool got you down? Now is the time to invest in a new efficient electric heat pump.

These are questions which should be asked when thinking about purchasing a new electric heat pump for your swimming pool or spa.

- How many BTUs will you need?

- Do you have the electric service required for a heat pump?

- Is there sufficient space available to install a heat pump?

- What type of features do I need?

- Plastic or metal cabinet?

- Titanium heat exchanger?

- Digital controls or analog?

Let's try to answer the questions above thus allowing for an educated purchase of your new pool heater.

- How many BTUs will you need? - The size of your pool (amount of gallons and surface area square footage will dictate the BTUs required to heat the pool or spa in the most efficient manner. Also take into consideration the amount of strong wind which will effect your pool and whether or not you will be using a pool blanket to help hold the heat into the pool. Check the manufactures recommended sizing chart to help determine the correct size and model for your application.

- Do you have the electric service required for a heat pump? - Most heat pumps required 220Volts of electric and many require separate 50 to 60 amp breakers. Check with your electrician to make sure you have sufficient electrical power to operate your new heat pump.

- Is there sufficient space available to install a heat pump? - Most heat pumps will require a "footprint" area of about 40" x 40" and about 40" in height. Heat pumps need good air circulating space area around the units to allow for peak operation.

- What type of features do I need? Today's heat pumps are manufactured with many different features, some are, Dual thermostats (great for a pool and spa combination), Scroll compressors, Extra quiet fan motors, Extended warranties, Built in water bypass valves, Ability to operate motorized valve actuators, Easy to see readouts with diagnostic trouble shooting messages, and many more. Check the manufactures literature to make sure you are choosing the heat pump with the features best suited for your application.

- Plastic or metal cabinet? Is you pool located in a location which would be better suited for a plastic cabinet?

- Titanium heat exchanger? The heat exchanger is the piece of equipment located inside the heater which the pool water flows through. Titanium is a forgiving material in that it allows for a greater tolerance of water chemistry problems. Other types of heat exchanger material is much more susceptible to problems with poor water chemistry. Please note: Proper water chemistry is a must when using any type of pool heater.

- Digital controls or analog? The controls on the heater can be digital electronic or analog. Once again it is best to consult the manufactures literature to gather which would be best for your application.

A swimming pool or spa heat pump is a large investment and should be researched carefully. Purchase the correct unit and you can expect many years of warm enjoyable water to swim and relax in.

Ron Burr is the owner of One Stop Pool Supplies and also a State of Florida licensed swimming pool contractor actively building swimming pools and spas in South Florida. Ron has been involved in the swimming pool industry for over 30 years. Visit our web site http://www.onestoppoolsupplies.com to learn more about all the items which have been mentioned to make your new or existing pool more exciting

Why You Need a Fireplace Heat Exchanger

2009-02-20T08:44:00.000-08:00

A fireplace is an enjoyable way to heat your home, but it's also not a very effective one if you are not using a fireplace heat exchanger. Most people that use a fireplace to heat their homes don't even realize that it is not heating their home efficiently. Of course, by improving the performance of your fireplace, you will also be saving on the cost of heating your home.

When you use a fireplace to heat your home, the fire must conduct air in order to keep burning. The air being drawn into the fire is the warm air from your home, and that air is being replaced by cold air from outside your home. In essence, your are creating a air current cycle that brings cold air into your home and pushing fire heated air out through your chimney.

Of course, there are dangers involved in building a fire inside your home, so you will want to follow all necessary safety precautions when using your fireplace. However, if you really want to keep your home warm in winter, watching your heat go out the chimney and get replaced by cold, outside air is not the best way to do it. In fact, very many people even wonder how it is that others are able to keep their homes nice and warm with their fireplace.

The answer is to use a fireplace heat exchanger. By using a fireplace heat exchanger, you will be able to stop using the warm air in your home to fuel the fire and start having the fire warm the air in your home. These devices force air, heated by your fireplace, directly back in the the room that the fireplace is in. Instead of all that hot air escaping, it is pushed right back into your home, where you really want it.

In most cases, you will need to spend about 500 dollars to get a fireplace heat exchanger.While that is a big expense, so is the firewood you are burning to heat the sky above your chimney. By making your fireplace able to heat your home more efficiently, you are saving a bundle of money in the long run.

You can learn more about fireplace heat exchangers, as well as the importance of furnace heat exchangers cleaning on my heat exchanger cleaning equipment site.

Interesting Facts About Wood Furnaces

2009-01-31T22:23:00.000-08:00

Wood furnaces are direct fire heaters. It is a convenient and economical way of heating homes. Many Americans, Europeans, Canadians and people from other countries who experience very cold weather or climate use this kind of unit.

Many users nowadays prefer using wood furnaces to save the Earth from greenhouse effect. Burning bio-mass fuels does not increase the risk of carbon dioxide in the atmosphere. Since wood is a renewable resource safe for the environment, it can also conserve energy.

There are three main types of wood furnaces. First is the Central Wood Furnaces. It can be installed inside the house, garage, mechanical room or at the basement. It uses either a type of forced-air or hot-water system to distribute heat throughout the house.

The second type is the Multi-Fuel Furnaces. This unit can be placed inside or outside the house. It enables the burning of different kinds of fuel like coal, oil, gas and wood. These types are flexible that can work as a back-up option, especially when using other kinds of fuel. It is appropriate in cases where there is only one chimney outlet available. The machine allows venting of the wood as well as the fossil fuel so as to exhaust-up the same pipe.

The third type is the Outdoor Furnace or Boilers. This unit utilizes firewood, particularly when there is a huge supply. It keeps the smoke, mess and bugs outside. The furnace is similar to a small utility building. It is a wood burning furnace placed outdoors. It can be found along the yard, between 50 and 150 feet away from the house.

The furnace firebox is surrounded by a water jacket. As heat is released, it is transferred from the fire onto the water. It is then pumped through insulated pipes and placed underground, then into your house. Finally, heat radiates to warm up the entire house.

On the downside, this unit needs some boots, gloves and a cap to slog out onto the blowing snow to keep it going. Many outdoor boilers are hard to control for a clean burn due to their oversized firebox. Aside from this, it tends to smoke a lot during automatic restart after a long off cycle.

All these wood furnaces are controlled by a thermostat similar to other heating systems. Different heating systems are used on working on these types.

The forced hot-air systems use heat exchangers. The warm air spreads out with ductwork. Burning fuel causes the heat exchanger to heat-up. However, there is no heat storage capacity in this system. The unit needs to be re-fueled everyday to maintain its temperature during the cold months. It is also easy to add filtration, air-conditioning and humidification because the air in this system is being re-circulated. Hydro-air units use ductworks to help distribute air similar to forced hot-air systems. The heat exchanger is replaced by a hot water coil being heated by a hot water loop from its boiler. There are multiple hydro-air units that can be fed by a single boiler throughout the sections of the house for different cool zones. This kind of system is always combined with air-conditioning.

A combination central-heating unit system is designed to burn wood, oil or gas. It relies on the back-up fuel when the wood is not convenient for usage. Both combustion chambers can be maximized with this design. The two fuels are not usually used simultaneously. It can either be hot-air or hot-water furnaces. The disadvantage of this unit is that it tends to be twice as expensive as a single-fuel heater. This dual system offer maximum fueling flexibility.

Wood furnaces have disadvantages also. Some needs to be refueled several times and are a bit dirty to operate. It is also not always convenient to gather fire woods. And to produce good heat, you must know how to stack these pieces of wood properly. Lastly, all these units require electricity due to its thermostat.

For more information on Wood Furnace and Outdoor Wood Furnace please visit our website.

Goodman Heat Pumps - The Paragon of Quality Heating

2009-01-06T05:32:00.000-08:00

Goodman is widely known to be the second largest manufacture of Air conditioners used for residential purposes and heating systems in Northern America. Goodman Heat Pumps is one of the most famous lines of Goodman brand.

Here is a list of some of the fabulous products promoted by Goodman Heat Pumps:

dedicated Horizontal 13 SEER GPH13H
Multi-position 13 SEER GPH 13M commercial
Multi-position 13 SEER GPH 13M international
Multi-position 13 SEER GPH 13M
16 SEER SSZ16
14 SEER SSZ14
14 SEER GSH13
13 SEER GSH13
GSH commercial products
GSH international products

The total package of Goodman Heat Pumps includes the following:

A compressor or motor unit
Air coil
A fan
A motor
A heat exchanger

Goodman Heat Pumps can also work as a superb refrigerant. A refrigerant is known to be a substance that facilitates heat transfer.

These are a gas and tend to result in condensation as these make their way in to the air coil. The air coil technology is widely used to manufacture these pumps.

One of the best things about Goodman heat pumps is that these also include geothermal heat pumps. These are known to be more efficient as compared to the other types of pumps. The logic behind the greater efficiency is that during winter, the soil temperature is warm. The air source heat pumps tend to move heat from cold outside in to the inside and this in contrast makes it quite hard to function.

Goodman Heat Pumps network has its' distribution points over 700 different places. The distribution points are located in the following centers:

Texas
California
Florida
Nevada
Arizona

When it comes to the types Goodman heat pumps available on the market, these days there are in abundance. Hence, there will be one for everyone's requirement.

The best part is that they also manufacture supreme quality air conditioner systems.

Many customers had some wonderful experiences with Goodman heat pumps. All these people are extremely happy with the performance, quality and supremacy of the brand. The products are reliable and the best part is that these are available at a lower price.

The company is also eminent for its wonderful gas fireplaces, coils and air quality products. In case, you have already decided on purchasing Goodman heat pumps, you must know about what is included in the purchase.

A total purchase of a quality of a Goodman heat pump, here is what will be included in to the package:

A heat exchanger
An air coil
A compressor.

The air coil is a large element and utilized for the purpose of condensation. The refrigerant facilitates heat transfer and save a lot of money on the energy bills.

We provide information for the consumer on heat pump prices along with information on specific brands such as Goodman heat pumps.

http://www.heatpumpsrus.com

By D. Karlson

Radiant Floor Heating For Comfort And Efficiency

2008-12-05T05:30:00.000-08:00

Radiant floor heating is an efficient and comfortable way to heat your home. It provides superior comfort to compared forced air heating because the heat emanates from the floor, and rises. The air cools somewhat as it rises. This allows the temperature at the feet and legs to be slightly warmer than the temperature in the air around the head.

Radiant heat is produced from either hot water flowing through a pipe system in the floor (hydronic), or by electricity. Hydronic systems are more complicated to install than electric systems, because the pipes need to be set in the cement under the floor. Obviously, this is expensive to install, but hydronic floor heating has it's advantages over electric heating.

The water holds the heat much better than electric wiring does, and as a result, is more efficient. It also allows for a variety of ways to heat the water itself. You can use gas, propane, oil, electric or even solar heat. Any traditional heating method is a usable option for heating the water that runs through the underfloor tubing.

Electric heat functions like an electric blanket. As electricity flows through the wiring, it encounters resistance, which causes the wires to produce heat. This is much less expensive to install than hydronic heating. It's easy to find floor tiles with the electric wiring built in, ready to just place and install. These are easily available at just about any home improvement store.

Radiant floor heating is especially popular in rooms that are commonly floored with tile, such as kitchens and bathrooms, but it can be used in any room, or the house as a whole, with any type of floor covering, including hardwood and carpet. It's quite nice to walk into the bathroom on a cold day and notice nice, warm tile on your bare feet. This simply isn't available with forced air heat, unless you keep the temperature uncomfortably warm.

Another advantage of radiant floor heating over traditional forced air heat is that there is no air being pushed through the home. This seems almost obvious, but when air is being pushed through the home it can suck the humidity from the air, especially if there a a leak in the system allowing the dryer outside air to mix with the air being heated.

It also can distribute allergens through the air in your home. Of course, there is also the issue of feeling hot air blasting on you while the heat is on. If you're in the wrong part of the room, it's still too cold. In yet another equally wrong part of the room, you're being hit with hot, dry, allergen carrying air. Neither of these options are particularly comfortable.

Overall, radian floor heating may be a little more expensive to install, but in the long run, it will be a more efficient and cost effective way to heat your home. It will also be much more comfortable. That's a double bonus in my book. I would ask, what's the price you would put on your comfort, but the reality is that it's going to be a big savings in the end.

Alex Parry is the author of a heat exchanger cleaning equipment site, where you can also find more information on shell and tube heat exchanger design

Avoid Premature Heat Exchanger Failure With Your Furnace

2008-11-02T06:57:00.000-08:00

Just as you may have noticed that your automobile runs more smoothly after a fresh new oil change, the same principle works for your furnace, when it comes to a new or clean furnace filter. The main component for both hot water and forced air heating units is called a heat exchanger. The purpose of this nifty component is to take the heat that is produced by burning fuel in your furnace, and to transfer it into the water or air so that it can be distributed through the entire house. The heat exchanger is traditionally concealed from view in hot water heating systems, and is only occasionally visible in forced air systems.

If you look at a modern forced-air gasoline-powered furnace, here is everything that you will find. First, you will find a solid-state furnace control, which has a fan assembly and is visible in the power rear of the furnace. Next, you will find a draft inducer, which provides fan-forced exhaust. Third, you will find both an igniter, and a flame sensor, because your furnace is actually running on firepower. Next, you will find the gas valve and manifold, along with gas burners. On the outside of all of this you will have them, followed by furnace filters or other air filters. Keep in mind, several aspects of this concept will vary based on the model of furnace that you use, though some things will remain the same, including the igniter, the filter of the furnace and the heat exchanger.

The thing that makes heat exchangers malfunction or inoperative in general is the development of a hole, crack or warping that allows hot water to escape, or combustion exhaust to escape into the home's interior air. They do eventually crack or warp over time simply because of the constant heating and cooling that the system experiences throughout the year. However, most heat exchangers can last a significant amount of time, often past their predicted life span depending on whether or not conditions are ideal. Regular cleaning and maintenance of the furnace do play a large part in determining the life expectancy of a heat exchanger, as well as the environment that exists around the furnace unit.

Another heavy contributor to whether or not heat exchangers live out their lifespan properly is reduced airflow, which comes as a result of dirty furnace filters, dirty fan blades, obstructed air vents and dirty duct work. All of these factors contribute to wear on the fan motors, which can significantly reduce the efficiency of the furnace, prematurely burning out them as well. Both fuel-fired and forced-air furnace types are prone to overheating in response to airflow obstructions. Most modern furnaces are built in a way that allows them to shut down if temperatures become unreasonably high based on a dirty or overused filter. However, if the internal temperature elevation caused by dirt and debris is only moderate, the furnace may not switch off but the heat may still be enough to cause metal fatigue to the head exchanger, which can cause serious issues down along the line.

The best way to protect yourself from premature burn out of the heat exchanger in your furnace is to have an annual inspection and a monthly cleaning of your furnace filters. The exam, which should be conducted by a licensed mechanic, should be relatively inexpensive while affording you a great deal of peace of mind. Another useful innovation is the carbon monoxide or CO detector, which is an easy and inexpensive way to protect yourself against exhaust leaks from your furnace.

Bill Whitworth is a professional writer covering home health and safety issues. WEB Products, Inc., is a leading Internet destination for information about furnace filters, air filters, replacement air filters and custom air filters.

Crack Down on Heat Exchanger Fouling

2008-10-20T03:52:00.000-07:00

Heat exchangers are the unsung heroes of many industrial processes and as such they tend to be taken for granted - nobody likes paying for what is often seen to be unnecessary maintenance. Heat exchangers provide duty for so long, that when they start to drop in efficiency, it's usually a gradual process that goes largely unnoticed - until their performance has deteriorated sufficiently to be a problem. Then it really is a problem - and one requiring urgent attention.

What aggravates the situation is the heat exchanger that has never been cleaned properly, coupled with the commercial need to keep it on-line. When the decision is made to carry out cleaning, often nobody knows what the performance of the exchanger is meant to be, either because the drawings have been lost, or no record of any improvement was made after the original cleaning.

When the exchanger finally is opened up to ascertain the extent of the fouling, it's not surprising to find it is so severe that cleaning takes a lot longer than planned. Any benefit that might have been gained by a quick traditional clean is offset by the extended cleaning duration and costs - and, of course, lost production.

If that sounds like a nightmare scenario, bear in mind that this is the sort of situation specialist cleaning companies encounter every week. Cleaning is often carried out without any firm knowledge of how much of an improvement the cleaning will give and how long its effects will last. Having to make 'finger in the wind' predictions clearly is not a satisfactory way to plan maintenance.

One of the most popular and widely-employed heat exchanger configurations in industry, is the straight or hairpin shell-and-tube exchanger. With hundreds or thousands of small-bore tubes bundled together, the extent of quite modest scaling can involve major work to return the exchanger to anything near its commissioned performance. If the outside of the bundle is heavily scaled as well, the cleaning challenge rises by an order of magnitude.

There is potential to bring about a significant improvement in heat exchanger accessibility and 'cleanability', by working more closely with the people who design heat exchangers and fabricate industrial plants.

Better design would lead to improved cleaning - where improved means faster, cleaner and safer, possibly in-situ or even on-line and with better waste containment. It would then be easier and quicker to clean exchangers back to bare metal to return them to duty and their design performance faster.

Plants are generally specified and ordered on the basis of throughput, not accessibility and ease-of-cleaning. Suppliers are happy to comply with this and therefore tend to design heat exchangers with 30-40% excess capacity to ensure that they can continue to provide duty, even when quite extensively fouled. Heat exchangers the world over are currently designed and installed with a view to using one of three systems for cleaning: chemical, pressure jetting and/or mechanical and this approach has remained unchanged for over 50 years.

When it comes to maintenance, refineries - like most of industry - tend to compete on the same basis - a 21-day shutdown is decreed because it's been done that way for maybe the last 20 years. The same cleaning methods are generally used slavishly, with high-pressure water as the cleaning medium.

Most companies look at their heat exchangers in isolation and simply try to extend their run-time, instead of having them designed or re-designed so they can be cleaned more regularly, but faster and better. BP's Coryton refinery, for instance, managed to reduce cleaning time on one shell-and-tube heat exchanger from three days to three hours by applying a different approach to cleaning it.

If a plant is optimized for cleaning, almost full production can be maintained throughout the cleaning process. Relatively minor mechanical changes, such as adding isolating valves to heat exchangers, means that each exchanger, or bank of exchangers, can be taken down and cleaned while the others remain on-line. A redesign of the exchanger so that a header can be removed, means it can then be cleaned with a different system to the standard high-pressure water jetting, in a few hours instead of several days.

At Dow Corning's silicone plant in Barry, south Wales, a tubular boiler and fire tube in the Energy Recovery Unit (ERU) required the removal of a 5mm layer of deposit in as short a time as possible to minimize lost production. Another obstacle was that the unit, which carries waste gases, takes 48 hours to cool and prepare - even with the introduction of a chilled nitrogen purge - before personnel can enter to clean it manually.

The solution involved developing a bespoke remote de-scaler, which was inserted through a small 50cm man-way. Once inside, the de-scaler expanded to fit the hot fire tube, while reaching the full length of the carbon steel tube. With cooling time and man entry eliminated, the shutdown was reduced from five days to three and there was a noticeable improvement in performance of the ERU when it came back on line.

Improved cleaning cycles also mean the rate of future fouling build-up is reduced, which in turn reduces the risk of tubes corroding as a result of the exchanger being open to the atmosphere longer for cleaning.

Heat exchange surfaces therefore remain smoother and provide better heat transfer. If and when the exchanger does foul up, it's easier to clean next time around, using whichever system is preferred. This would represent a change of practice to what has been the norm since the 1980s, for instance, when what was then Mobil in the UK was one of the first refineries to decide that it would extend run-times by abandoning the annual clean and only clean every two years.

Today, typical service intervals have become stretched to three and even four years in some cases, but the apparent operational savings are actually a false economy. Shareholders are indeed happy, because they are getting longer run times, while competing refineries have little choice but to play the same game or lose millions during more frequent shutdowns. Four years down the line, however, the plant will have to come down for major cleaning and maintenance and it will experience a far higher capital replacement cost than ever before.

Mike Watson, Managing and Technical Director

Run by its founder and inventive visionary Mike Watson the company is supported by a wealth of hand selected department managers. With many years experience in developing engineered solutions to complex problems in industry, Mike’s belief is that convention should always be challenged in order to find a better way to achieve improved results. This “never say never” approach, led to him founding Tube Tech in the 1980s. Today, the company cleans the toughest cleaning projects the world can throw at it. Mike often says “If people say it can’t be done, its like a red rag to a bull to me. I will always find a solution”. Mike continues to invest in new technology development, leading the world in new cleaning methodology.

Article Source: http://EzineArticles.com/?expert=Mike_Watson

What is a Fireplace Heat Exchanger?

2008-10-17T09:11:00.000-07:00

A furnace centrally heats most homes today so their fireplace does not need to be the main heat source. If more heat output is required then homeowners should look at a fireplace with a fireplace heat exchanger or glass front. These allow more heat into the room based on their design.

A fireplace heat exchanger can be for either a wood burning or gas fireplace. The United States Department of Energy indicates that by using an exchanger you can increase the overall heating performance of the fireplace by five to ten percent. They recommend that this feature be added during the initial installment of the fireplace, but not all contractors agree with this statement.

A fireplace heat exchanger uses a fan to heat the air by pushing it through hot tubes. The tubes then allow the heated air to continue to circulate rather than relying on the process of natural convection. It is important that the exchangers be cleaned frequently because soot accumulates in the tubes. This accumulation will affect the performance of them.

Another term for a fireplace heat exchanger is a blower. The heat exchanging tubes wrap around the fire. The blower will draw the room air in and then returns the fire heated air back into the room. This apparatus will fit into the existing fireplace and if needed can be adjusted by using a trim kit so that it fits properly. If you do not know whether you need a chimney liner for the exchanger then consult your local building codes accordingly.

As mentioned earlier, both gas and wood fireplaces can use a fireplace heat exchanger. The natural gas style fireplace circulates heat by convection and radiation. Radiant heat transfer heat to solid objects but not the air around you. When referring to solid objects, that means anything such as people, walls and furniture as well. Radiant heat allows you to feel warm but the air around might not feel warm. Therefore, the hotter your fireplace gets, the more radiant heat will circulate.

We provide information on all things related to fireplaces such as a fireplace heat exchanger, ventless fireplaces and fireplace rugs along with many other items concerning your fireplace.
by D. Karlson

What is a Fireplace Heat Exchanger?

2008-10-07T19:13:00.000-07:00

Designing An Optimal Heat Exchanger from The Quran

2008-09-28T10:36:00.000-07:00

If you think that the heat exchanger text book, software and experience is the only reference for you to design an optimal heat exchanger and heat exchanger tubing, then we should look at this interesting video. It shows in detail and provide valuable message on the ultimate optimal heat exchange design. Check it out:

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Better Heat Exchanger Cleaning Through Technology

2008-09-26T11:48:00.000-07:00

Maintenance of a platform's Waste Heat Recovery Unit (WHRU) and similar shell and tube heat exchangers can be an extremely dangerous process. It needs to be disconnected, taken off line, and moved to shore for repair. Shell and tube heat exchangers are made of coiled tubes and can become fouled with carbon deposits. The traditional methods for clearing the blockage include bypassing the fouled unit, cutting off bends and cleaning the tubes, then re-welding the U-bends, and complete unit replacement.

The old methods are becoming more outmoded due to advancements in technology. It is inefficient to bypass the unit. Just as it would be less efficient to run your car with 2 cylinders not firing. This inefficiency, of course, also increases operational costs. It is time consuming and costly to cut the U-bends and re-weld them. Sometimes it can be difficult or impossible to get access to reattach them.

Some of these new methods include the ability to clean areas with limited access, and clear deposits from U-bends without ever removing them. This can sometimes be done without even taking the unit offline, and usually takes less time and results in a higher degree of defouling. In fact, many units can be restored to near-factory efficiency. For big refineries, petro-chemical plants, or power plants, this can amount to six figure savings.

The U-bends themselves also retain many deposits, and continue to be a bottleneck to the system. Full replacement carries the cost of completely replacing equipment that, other than the heat exchanger tube fouling, is still in working order. This method also requires the unit be taken offline for the full duration of replacement. obviously this carries a heavy expense and serious loss of production.

Traditional heat exchanger cleaning methods and heat exchanger cleaning equipment have changed very little over the last few decades. Pressure jetting is still the primary means used by many companies, but it is slow, inefficient, and ultimately very costly. Additionally, many companies are skeptical of newer methods, falling back on the "that's the way it's always been done," chain of logic. They are also weary of trying new techniques that are not as "proven" to be effective. Finally, many have long term tube cleaning contracts that do not allow for a change in heat exchanger cleaning technique, unless the contractor were to adopt the new methods.

Newer heat exchanger cleaning equipment and techniques are more technologically advanced, and by extension, require a higher skilled laborer than old style pressure jetting. These new developments include the ability to clean tight radius bends, clean units while keeping them in place, and even while keeping them online. It has also resulted in faster, more efficient cleaning. Many tube bundles can now be cleaned more effectively than with pressure jetting, and jobs that used to take days may now take only a few hours. Difficult to access units are now accessible with these new technologies.

Some of the technology that has been developed includes special nozzles that can be used on tight bends, laser cleaning, and new "smart" metals that respond to changes in density and pressure to prevent damage to the tubes. With these methods, jobs can be finished with less downtime, because cleaning and descaling can be done more quickly. Equipment is also less likely to be damaged in the process. Many of these new processes are safer, create less waste, use no chemicals, and have a significantly reduced environmental impact.

The article was written by Alex Parry who writes about heat exchanger safety at his heat exchanger cleaning equipment site.

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Cleaning Plate Heat Exchanger Matter

2008-09-17T09:18:00.000-07:00

I made a post entitled "Learning Process From Cleaning Plate Heat Exchanger" which was a follow up entry from "Some Updates". You can refer to the 2 posts for reference. From that post, I received some interesting response and questions from few engineers asking more detail about the cleaning of heat exchangers. The questions are taken from the comment section of that Learning Process From Cleaning Plate Heat Exchanger post without any editing. I answered the questions but I add more of my answers here after thinking about it...

Questions:

I'm a process engineer and your article is very useful and interesting. Could you say (if it possible) how long time did this plate heat exchanger work good without cleaning? And was the concentration of caustic solution high?

Answer:

Thanks for your kind words Olga.

How long time did this plate heat exchanger work good without cleaning?

That depends on how you use the plate heat exchanger and the types and quality of fluid that passes the plate heat exchanger. From my experiences, the plate heat exchanger can operate effectively up to 1.5 years without cleaning, but that is because the feed oil is clean and other combining parameters are good. There are also cases where we have to clean the heat exchanger after 4-5 months... There's no straight answer to this. It depends on a lot of factors. You need to really sit down and monitor the processing parameters and the quality / condition of fluid entering it. I have about 16 plate heat exchangers which I monitored and all of them have different records. Those who belong at the same section in the plant will have almost similar cleaning track record. All of them have different classification of problems too. So, we need to really look at the heat exchanger(s) and make a proper inspection, evaluation and analysis.

The caustic concentration was 3-5%. This also depends on how severe the scale build up is inside the plates. You can have lower concentration if the scale is lesser. You can add up more of the caustic concentration, but it may be not good for your plates (of the plate heat exchanger) or the tubes (of the shell and tube heat exchanger).

Questions:

How heavy and fooling is that oil?

Does it really worth the trouble to use a plate exchanger respect to a shell and tube for such fluids? After all a shell and tube is much easier to clean.

Answer:

It depends on your process and application. What is the type of flow? what is the pressure and temperature? You have to use a shell and tube heat exchanger if you have a high pressure and high temperature. A shell and tube heat exchanger is more expensive. A plate heat exchanger is cheaper and can be used for lower temperature and lower pressure. The main constraint of the plate heat exchanger is because of the gasket used cannot cope with temperature higher then 200oC. so, it's a matter of the effect of process parameters and not the easiness to clean the heat exchanger. A shell and tube heat exchanger 2 pass (or U tube) is also sometimes very difficult to clear especially at the U bend. You need a special equipment with high pressure of jet water to clear the scale, fouling. In worse cases, you need to introduce a small drill combined with the high jet water, preferably up to 20,000 psi to ensure you eliminate the stubborn scale.

Hmmm...maybe those of you who have other experiences on dealing with heat exchanger cleaning can share it with us here...TQ!

The author of this post is Zaki from Chemical Engineering World - subscribe to the blog...
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Furnace Flue Heat Exchanger - Economizer

2008-09-06T10:19:00.000-07:00

This is an interesting video about how to make full use of the energy from a heat source. In this case it is a furnace and it acts as an economizer. The video shows how waste heat from the furnace is used to pre-heat the hot water tank feed reducing the amount of energy required and the GHG emissions released. Check it out...

Heat Exchangers for Outdoor Corn Boilers

2008-09-06T10:08:00.000-07:00

A heat exchanger is a device designed to efficiently transfer the heat from one medium to another. In the case of an outdoor corn boiler, these media would be air and water.

A typical domestic setup would include a water-to-water heat exchanger for hot water and a water-to-air heat exchanger for forced air home heat. Water-to-water heat exchangers are also used to heat hot tubs, swimming pools and the water for radiant baseboard or radiant in floor
heating systems.

Water-to-Water Heat Exchangers

The three most common types of water-to-water heat exchangers used with outdoor
corn boilers are: Sidearm, Shell and Tube, and Brazed Plate. What differentiates these heat exchangers, besides the cost, is the way they're designed to transfer heat from one medium to another and the method used to create turbulence.

A key component in the efficient transfer of heat between liquids is turbulence. The more turbulent the flow of water through a heat exchanger, the more efficiently heat is transferred.

Sidearm Heat Exchanger

The sidearm heat exchanger is a popular and inexpensive choice for heating domestic hot water. It incorporates a pipe within a pipe design where the water in the inner pipe (your hot water) is heated by hot water from the boiler circulating through the outside pipe.

Turbulence is created by scrolling on the outer surface of the inside pipe.

This straightforward design prevents clogging by sediment and resists scaling. One drawback of the sidearm heat exchanger is reported slow recovery under heavy use. Cost: $130-$150.

Shell and Tube Heat Exchanger

Shell and tube heat exchangers are available in dozens of tube configurations and sizes ranging from a few feet long to 50 feet or more for power plant steam generation.

A variation on the shell and tube design is shell and coil where a helical (spiralling) coil
replaces the tubes.

No matter what the design or application, the basic principle is the same. The water to
be heated flows through tubes, and the heated boiler water, encased by the shell, flows around the tubes.

Turbulence is created by the baffles holding the tubes together in what is called a tube bundle.

Shell and tube heat exchangers for non-chlorinated water applications, such as domestic hot water and hydronic heating, are usually constructed with a brass shell and copper tubes.

For swimming pools and spas the shell should be PVC or stainless steel with stainless
steel tubes. 316L grade stainless steel is commonly used for this application.

Cost: $200-$600 depending on copper or stainless construction and the overall size based on the volume of water to be heated.

Brazed Plate Heat Exchanger

The brazed plate heat exchanger combines compact size with a highly efficient design to produce a device for heat transfer that is up to six times smaller than a shell and tube heat exchanger of similar capacity.

The key to this efficiency lies in their unique construction. Corrugated stainless steel plates are brazed together (eliminates gaskets) with every second plate turned 180 degrees. This design creates two highly turbulent fluid channels that flow in opposite directions (counter flow)
over a massive surface area.

Cost: $100-$500 depending on capacity.

Get better outdoor corn boiler information at Alternative-Heating-Info.com

TLC For Your Furnace - Avoiding Premature Failure of Heat Exchangers

2008-05-12T08:23:00.000-07:00

Ever notice how your car seems to run better right after an oil change, especially if you wash and wax it? Well, it's the same for your furnace... don't laugh, I'm serious!

The main component of heating units, both forced air and hot water, is the heat exchanger. This component takes the heat produced by burning fuel and transfers it to the water or air for distribution throughout the house. In a hot water system this component is usually concealed from view, and in a forced air unit only 10 to 25% (sometimes it's completely hidden) of this component is typically visible without disassembly.

Cut-away view of a modern forced-air gas furnaceModern forced-air gas furnace:

1. Solid-state furnace control (Fan assembly visible at lower rear)

2. Draft inducer (fan-forced exhaust)

3. Igniter and flame sensor

4. Gas valve and manifold

5. Gas burners

6. Heat exchanger(s)

7. Air filters

(Configuration will vary between models)

What usually makes heat exchangers inoperative is developing a hole or a crack that allows the hot water to escape, or exhaust from the combustion fuel to escape into the interior air of the home. Constant heating and cooling from years of use will eventually cause a heat exchanger to crack, however some last longer than others. Under ideal conditions, many survive well beyond their predicted life spans.

It seems regular cleaning and maintenance play a factor in life expectancy, as does the environment surrounding the unit. Damp environments tend to assist the build-up of rust on the heat exchanger, shortening its life, while dry, clean environments tend to increase the life span of most furnaces.

Reduced airflow...

Dirty air filters and fan blades, dirty ductwork and obstructed air vents can all contribute to wear on fan motors, reduced efficiency and even premature failure of heat exchangers. Fuel-fired forced-air furnaces are prone to overheating due to obstructions to airflow. Modern furnaces are designed to shut down if temperatures become dangerously high... however, moderately elevated internal temperatures caused by dirt, dust and debris may not be high enough to switch off a furnace, while remaining high enough to cause metal fatigue over extended periods of time.

An annual internal inspection by a licensed burner mechanic or gas fitter, including cleaning and testing for exhaust leaks, should cost between $50 and $100. Considering the implications, I'd say that's a real bargain! Why not have your furnace inspected, and treat yourself to some peace of mind? For those of you with gas furnaces or wood stoves, a carbon monoxide (CO) detector ($30-$45) is an inexpensive means of protection against the possibility of exhaust leaks, between inspections.

Gil Strachan is a professional home inspector, representing Electrospec Home Inspection Services in east-central Ontario, Canada since 1994. Visit http://www.allaroundthehouse.com to learn more about home inspections.

"The Home Reference Book"

Explosive Air

2008-04-26T04:44:00.000-07:00

Have you considered your air compressor as a potential bomb?

If you have not, then you better!

Although air compressors are built to withstand high pressures, and will have all the necessary relief valves to take care of normal occurring overpressures, explosion involving fire propagation is another matter.

How can a fire occur in an air compressor?

In order to understand the phenomenon of explosion, we have to understand the nature of fire, because, after all, an explosion is a very rapid propagation of fire.

A fire will only start whenever three conditions are met - fuel, oxygen and heat.

An air compressor when operating will have a very rich supply of oxygen already in place - pressurized oxygen.

Where do we get the fuel?

If you use oil lubricated air compressors, the lubricating oil can become the source of fuel. It can also be in the form of carbon dust. Carbon is formed when oil is heated to high temperatures.

How is it possible to have high temperatures to ignite the combustible mixture?

There can be a lot of reasons - lack of lubrication due to oil deterioration, reduced lubricating quality of the oil, oil pump mechanism fault, oil filter choked, worn out parts leading to lessen oil pressures, etc. Whenever there is a hotspot sufficient to ignite the combustible mixture an explosion will occur. That is the extreme case.

Let's see what can happen that can lead to that extreme case of an explosion.

All the above reasons for lubrication failure or deterioration will gradually cause the machine to operate poorly, wear out the moving parts, cause oil spills and carry over of the oil in the air passages and increased heat built-up.

Now comes the cooling part. Is there a lack of cooling? If the high temperatures due to rubbing of parts from the above are not cooled down sufficiently, the heat will build up. The intercoolers play a very important role in removing the heat?

There are also many other reasons for the lack of cooling.

When the heat transfer surfaces have been coated by films of scale or carbon it will definitely affect the cooling process. The heating surfaces may have been reduced due to choked passages for the cooling medium in the heat exchanger. The cooling medium itself may be too hot probably due to a fault in another machine like the cooling tower where the heat can be taken away to the atmosphere.

The flow of coolant can sometimes be the culprit. When the cooling pump fails, or the driving belt snaps there will be a lack of coolant flow. One must also find out whether the valves for coolant have been accidentally closed or not.

Very often, the effects build upon one another in a vicious cycle - poor heat transfer leads to more heat that carbonizes more oil which coats the heat transfer surfaces more...which leads to worse heat transfer...

Therefore use oil lubricated air compressors with caution. If your air compressors have been running for a long time, chances are, your air compressor pipelines may have already accumulated a sizable amount of oil carried over together with the air flow during operation.

Does your air compressor work non-stop? Is the inter-cooler or the after-cooler efficient? Is your compressed air hot? These are the questions you have to ask yourself.

The oil film in the pipes turns to carbon with heat. The oxygen-rich and moist atmosphere inside the pipes can turn the oil into acids that can further deteriorate the oil to form other organic compounds, perhaps some highly flammable products.

It just needs a spark or a hot spot to ignite this.

Boom!!

Did I frighten you?

What you need is good preventive maintenance. An air compressor working at peak condition with good cooling, good lubricating pressures, and good lubricant and good parts should give trouble-free performance throughout its lifetime.

Sometimes the compressor may have reached the point of no return - coated coolers leading to high temperatures that lead to more coated cooling surfaces that lead to higher temperatures... In this case it is safer to discard the compressor altogether and obtain an entirely new compressor unit. It could be more economical - and safer!

If you do that, do ensure that preventive maintenance is done regularly to keep the unit at peak operating conditions all the time.

An explosion in an air compressor can have grave consequences. Don't take any chances. Perform regular preventive maintenance or buy a new unit before an explosion occurs.

Until next time…

Locate good air compressors for your garage and workshop here:
Eastwood

Many years of working experience in Marine, Facilities, Construction has given the author material for writing e-books and articles related to engineering, and management.

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More information at Marine Engineer

Energy Related Terms Explained

2008-04-26T04:42:00.000-07:00

Below are some terms you may encounter while researching energy related products, heating and efficiency:

AFUE (annual fuel utilization efficiency): an efficiency rating that measures the efficiency with which gas and other fossil-fuel-burning appliance use their primary fuel source over an entire heating season. It does not take into account the efficiency with which any component of the system, such as a furnace fan motor, uses electricity. AFUE is expressed as a percentage that indicates the average number of Btu worth of heating comfort provided by each Btu worth of fuel consumed by the system. For instance, a gas furnace with an AFUE of 80% would provide 0.8 Btu of heat for every Btu of natural gas it burned.

Air infiltration: the introduction, usually unintentional, of unconditioned outdoor air into a mechanically heated and/or cooled building. Air infiltration can occur through any opening in the home's structure, including seams where walls meet other walls, window or door frames, or chimneys; holes where wires or pipes penetrate walls, floors or ceilings/roofs; and between the loose-fitting meeting rails of double-hung windows or a door bottom and door threshold. It is one of the major causes of unwanted heat gain and loss, and personal discomfort in buildings.

Alternating Current (AC) - An electric current that reverses its direction at regular intervals or cycles; In the U.S. the standard is 120 reversals or 60 cycles per second; typically abbreviated as AC

Amp - short for "ampere" - this measures the amount of electricity moving through a wire. Most household appliances use 15 or 20 amps of power. Amps are what give electricity its "shock."

Biomass Fuel: Any organic (plant or animal) material which is available on a renewable basis, including agricultural crops and agricultural wastes and residues, wood and wood wastes and residues, animal wastes, municipal wastes, and aquatic plants

BTU (British thermal unit): a measurement of the energy in heat. It takes one Btu of heat to warm one pound of water by 1° Fahrenheit. Btu can be used either to define an air conditioner's cooling capacity (i.e., the number of Btu of heat that can be removed by the system) or a furnace's heating capacity (i.e., the number of Btu of heat that can be supplied by the system).

Chemical Energy - Energy stored in a substance and released during a chemical reaction such as burning wood, coal, or oil.

Combustion - Chemical oxidation accompanied by the generation of light and heat.

Conduction is the transfer of heat through solid objects such as glass, dry wall, brick and other building materials. The greater the difference between the outdoor and indoor temperatures, the faster conduction can occur, increasing a building's energy gain or loss.

Convection is the transfer of heat to or from a solid surface via a gas or liquid current. Where home heat loss and gain are concerned, heat convection is caused by air (gas) currents that carry heat from your body, furniture, interior walls and other warm objects to windows, floors, ceilings, exterior walls and other cool surfaces.

Conversion- A number that translates units of one measurement system into corresponding values of another measurement system.

Cord of Firewood: a tightly stacked pile of wood logs measuring 4' x 4' x 8' (128 cubic feet).

Daylighting is the technique of using natural light from windows, skylights and other openings to supplement or replace a building's artificial lighting system. When applied properly, daylighting can reduce lighting costs. When applied improperly, however, it can not only lead to inappropriate light levels but can also raise the building's cooling costs by introducing high levels of solar heat into the interior of the building. Also see SOLAR GAIN to see how sunlight can affect heating costs.

Direct Current - An electric current that flows in only one direction through a circuit, as from a battery. Efficiency is the degree to which a certain action or level of work can be effectively produced for the least expenditure of effort or fuel. BTU of energy consumed (input) x efficiency = BTU output.

Energy: The ability to do work or the ability to move an object. Electrical energy is usually measured in kilowatthours (kWh), while heat energy is usually measured in British thermal units (Btu).

Energy Efficiency - Refers to activities that are aimed at reducing the energy used by substituting technically more advanced equipment, typically without affecting the services provided. Examples include high-efficiency appliances, efficient lighting programs, high-efficiency heating, ventilating and air conditioning (HVAC) systems or control modifications, efficient building design, advanced electric motor drives, and heat recovery systems.

Emission- A discharge or something that is given off; generally used in regard to discharges into the air. Or, releases of gases to the atmosphere from some type of human activity (cooking, driving a car, etc). In the context of global climate change, they consist of greenhouse gases (e.g., the release of carbon dioxide during fuel combustion).

Heat Content - The gross heat content is the number of British thermal units (Btu) produced by the combustion, of a volume of gas under certain with air of the same temperature and pressure as the gas, when the products of combustion are cooled to the initial temperature of gas and air and when the water formed by combustion is condensed to the liquid state.

Kilowatt-hour (kWh): 1000 watts used for one hour - or any combination of energy multiplied by time that is equivalent to that rate of electrical consumption, such as one watt used for 1000 hours, 10 watts used for 100 hours, or 50 watts used for 20 hours. For example, a 100-watt light bulb left on for five hours each day would consume one kWh every two days. Kilowatt-hour is the primary measure on which U.S. electric companies base most customer billing.

Load Estimate is series of studies performed to determine the heating or cooling requirements of your home. An energy load analysis uses information such as the square footage of your home, window and door areas, insulation quality and local climate to determine the heating and cooling capacity needed by your furnace, heat pump or air conditioner.

Mercaptan - An organic chemical compound that has a sulfur like odor that is added to natural gas before distribution to the consumer, to give it a distinct, unpleasant odor (smells like rotten eggs). This serves as a safety device by allowing it to be detected in the atmosphere, in cases where leaks occur.

Methane -A colorless, flammable, odorless hydrocarbon gas (CH4) which is the major component of natural gas. It is also an important source of hydrogen in various industrial processes. Methane is a greenhouse gas.

Operating Cost is the day-to-day cost of operating an appliance, based on energy use.

Payback period is the amount of time it takes to achieve a full return on an investment. For instance, if a high-efficiency direct vent gas fireplace costs $1000 more than a purely decorative fireplace but would save $500 a year in gas usage, the payback period is 2 years.

Propane (C3H8) - A normally gaseous straight-chain hydrocarbon. It is a colorless paraffinic gas that boils at a temperature of -43.67 degrees Fahrenheit. It is extracted from natural gas or refinery gas streams.

Radiation is a method of heat transfer in which heat is transmitted from surface to surface via infrared waves. Radiant heat warms the surfaces it touches without increasing the temperature of the air through which it travels. All warm bodies radiate infrared energy.

R-value is a measurement of a material's ability to resist heat transfer. Insulation products are rated according to the R-value. The higher its R-value, the greater the product's ability to resist heat flow will be.

Solar Gain is the heat that builds up inside a structure as a result of sunlight that enters through transparent or translucent surfaces, such as windows, and is converted to heat after striking other surfaces inside the building.

Space Heating - The use of energy to generate heat for warmth in housing units using space-heating equipment. The equipment could be either the primary or secondary source of heating.

Thermal Energy - The total potential and kinetic energy associated with the random motions of the molecules of a material.

Thermostat - A device that adjusts the amount of heating and cooling produced and/or distributed by automatically responding to the temperature in the environment. Watt: a unit of electric power. The amount of power required by electric appliances is expressed in watts. Watt-hour is a unit of electric energy, equal to one watt used over a period of one hour.

Volt (V) - The volt is the International System of Units (SI) measure of electric potential or electromotive force. A potential of one volt appears across a resistance of one ohm when a current of one ampere flows through that resistance. Reduced to SI base units, 1 V = 1 kg times m2 times s-3 times A-1 (kilogram meter squared per second cubed per ampere).

Voltage - The difference in electrical potential between any two conductors or between a conductor and ground. It is a measure of the electric energy per electron that electrons can acquire and/or give up as they move between the two conductors. This is how electricity gets from the power plant to your house: high-voltage transmission lines carry the electricity under greater pressure to carry it long distances, while lower-voltage power lines serve individual homes and businesses.

*Article contributed by Karen Duke, Victorian Fireplace Shop

Karen Duke is a fireplace, chimney and hearth industry expert of over 25 years in both the retail and service sectors. She is a CSIA Certified Chimney Sweep and has numerous hearth industry certifications. She is the founder and webmaster of http://www.TheFireplaceChannel.com and she is the co-founder and webmaster of http://www.TheVictorianFireplace.com , which is one of the largest online fireplace retailers in the world. She makes her home in Mechanicsville, Virginia. Karen's contact information can be found on either of the above sites.

Alfa Laval Plate heat exchangers

2007-05-20T10:03:00.000-07:00

Alfa laval is one of various companies producing plate heat exchangers for chemical industry. I'm currently using 2 types of plate heat exchange in my plant (another brand that I'm using is Schmidt Bretten plate heat exchanger). I'm using the clip on gasket. It's easier using this type of gasket because it's faster to attached the gasket to the plate. Following is a brief explanation about Alfa-Laval that I adopted from Alfa Laval site.

Alfa Laval - choose a market leader
Alfa Laval is the leading manufacturer of plate heat exchangers in the world. We provide you with compact, modern solutions with the highest thermal efficiency.

Working principle
The basic plate heat exchanger consists of a series of thin, corrugated plates that are gasketed, welded together (or any combination of these) or brazed together depending on application. The plates are then compressed together in a rigid frame to create an arrangement of parallel flow channels. One fluid travels in the odd numbered channels, the other in the even.

Similar on the outside, unique on the inside
All plate heat exchangers look similar on the outside. The difference lies inside, in the details of plate design and the sealing technologies used. Alfa Laval is in the forefront of R&D work on plate heat exchangers. We continue to improve and develop products to optimise our customers processes. Time and time again (MORE).

Heat Exchanger Cleaning & Maintenance - GASKETs

2006-09-06T03:53:00.000-07:00

Continuation from previous post...

You can either dismantle all the plate and frame heat exchanger OR you do the chemical cleaning. Well, i can say the decision must be correct. You must decide which method to chose.

If you decide to dismantle the heat exchanger and heat exchanger tubes, this will give you the highest cost impact. Why? This is because, when you dismantle the plate & frame heat exchanger, the gaskets in between the plates cannot be used anymore. Once the heat exchanger is opened, it can't be used again. The polymer structure of the gasket has already be distorted and is not in a prefect condition to be used again. By the time you open the heat exchanger, some of the gasket, might also be damaged too. Some of them have became very thin. Some of them have been torn. There are many types of condition. And most of the time, oil leaks in the heat exchanger is due to the gasket problem or the operator/technician did not fix the gasket properly on plate heat exchanger.

Example of a gasket to be placed in between the heat exchanger plates

A cleared picture of how the gasket is inserted and attached to the plates

One set of gasket to be placed in between two plates is very expansive. Depending on what type of heat exchanger, type of plates, type of oils/fluids flowing, and also range of operating temperature. This information can be obtain from a gasket or heat exchanger supplier/manufacturer. So, imagine if the plate and frame heat exchanger have 220 plates, you must have 221 gaskets placed in between the plates and the two stainless steel frames on both ends.

2006-09-04T06:05:00.000-07:00

Heat Exchanger Cleaning

You have a plate and frame heat exchanger in your plant. The heat exchanger have been in operation for perhaps one year already. By this time, the efficiency have dropped. The heat exchanger cannot provide you the desired output temperature when they heat exchange.

How do you know this? You can know by seing the output temperature of both fluid ie the cold fuild and the hot fluid. If the output cold fluid temperature has increased and the output hot fluid temperature has decreased, then this are the sign of some sort of inefficient heat exchange situation. Why is this happening?

You can also check the pressure of the input hot or cold fluid, ie if the pressure increased, it is a sign of something called "fauling" which resulted in the heat exchange becoming inefficient. Yes, fauling is one thing that most of the time caused the heat exchanger to be not working optimumly.

All of these are just part of what you can notice and experience on your plate and frame heat exchanger. When this happen, you might want to consider removed the fauling from the plates.
But how? You have to options. You can either dismantle all the plate and frame heat exchanger OR you do the chemical cleaning. Well, i can say the decision must be correct. You must decide which method to chose. Because both will have direct impact on your production and/or operation and/or maintenance cost. So, you don't want to be caught making a bad decision by your superior!!! Ok. Let's continue in the next post....got more to tell....

2006-09-01T23:02:00.000-07:00

My first Heat Exchanger Encounter....

It was in my third working place that i learn and have better comprehension about the heat exchanger. There are various types of heat exchanger in plant. We have plate and frame heat exchangers, shell and tube, spiral cooler and others.

The first time i get to know a plate and frame heat exchanger was when i was instructed by my boss to supervise a group of technicians and contract worker fixing and installing about 233 plates onto a heat exchanger frame. It was not an easy job. The task was very physically demanding.

Plate & Frame Heat Exchanger - Hot fluids flow down between alternate plates, cold fluids flow up between alternate plates (Adopted from Perrys Chemical Engineering Handbook: Thermal division Alfa LAval, Inc)

While performing this task, we have to be careful of the plates arrangement. We have to be carefull of the numbers and quantity of the plates. I have witness one time, these people accidently missed out one plate, which can result in the 2 types of oil cannot pass through. Thus, upsetting the initial intention of heat transfer. As soon as they realized that they miss out one plate, they decide to put another extra plate in between to continue the path of the two oils not to be blocked. Well, that's ok. But, they need to be careful next time. Not to be careless and repeat the same mistake.

The technique to tightened the plate and frame heat exchanger must be correct. We must tighten it in a criss cross manner and in the same time take the measurements of all the bolt length. The tightening length must be the same for all 8 bolts (if there is 8 bolts).

There are still a lot more to tell about the hidden information of heat exchanger.....i mean the type of information and knowledge that is not written in the text book. The one that we can only know and get it from experience and other peoples experience. I'll share some of my experience of dealing with heat exchanger from time to time. I sincerely hope the information will be beneficial for those who want to learn and know more about heat exchangers, heat transfer.