Gas & Oil Furnaces

Click on the manufacturers listed below to go to their websites for viewing the many products in stock at DESCO Energy. Click on the underlined blue text for areas of more explanation in our website. Chose from a wide array of manufacturers including York, Tappan, Goodman, Gibson, Amana, Fedders and Reznor gas and oil furnaces. For assistance call us toll free at 877-265-9764 or email info@descoenergy.com

Gas Furnaces

High Efficiency Condensing Eligible for Tax Credits

95% AFUE 2 Stage & Variable Speed ($200 Tax Credit)

95% Multi-Speed Single Stage ($150 Tax Credit)

High Efficiency Condensing 94% or less 2 Stage & Variable Speed ($50 Tax Credit) 

Standard Efficiency 80% Two Stage & Variable Speed ($50 Tax Credit)

High Efficiency 94% or less Single Stage Multi Speed (No Tax Credit)

Standard Efficiency 80% Single Stage Multi Speed (No Tax Credit)

Coils

Cased Coils

Accessories

Concentric Vent Kit
Vent Wall Termination Kit
Propane Conversion
Thermostat

Oil Furnaces

Standard Efficiency 80% Upflow

Standard Efficiency 80% Lowboy

Standard Efficiency 80% Horizontal and Downflow

Ceiling Mount Gas and Oil Furnaces

Radiant Tube Gas Heaters

Packaged Systems with Gas or Oil Heat 80% Efficiency Only

To get started click on any of the blue words in this introduction for a more complete explanation. DESCO Energy and SEER Solutions for Energy Efficient Results will guide you through the entire process of sizing and selecting the most efficient system for your house or business. We recommend all potential customers review all the information provided in our Getting Started and Solutions section of the web site. When you're ready an Online Sizing Form using Manual J is provided to complete with detailed construction and sizing of your home including location and insulation values to determine the exact heating and air conditioning requirements of your building. This valuable information provides the necessary information to accurately select and size the heating and air conditioning system that's right for you.

Furnaces are rated for efficiency and capacity.  Efficiency is rated in levels of AFUE or Annual Fuel Utilization Efficiency. Capacity is rated in BTUS. Today's new more efficient systems are built better and they last longer. There have stronger warranties and more features than ever before to help you save energy. Many homes continue to heat with 80% furnaces opening many more opportunities to save energy. Newer furnaces feature benefits such as low electrical consumption with variable speed and less energy usage and perfect comfort through two stage operation. Today's new hi tech furnaces  operation provide better humidity and temperature control for heating and cooling. While the newest state of the art igniter technology ignition systems provide up to lifetime service without failure. Other energy and comfort features available are variable speed blowers to maintain constant air flows, increase dehumidification, reduce and eliminate blower noise and reduce electrical energy consumption 85%. While Auto Comfort Mode increases summertime dehumidification.

DESCO Energy will put together a complete package for your specific application including the new energy efficient fiberglass duct systems. Only here can you find a complete package including the duct air handling system designed and precut for your needs. Fiberglass duct board provides many features which surpass using more costly sheet metal ducting. Features and benefits of fiberglass duct board include easier installation, higher insulation, quieter attenuating the transmission of any noises, almost zero air leakage and thermal losses with no condensing compared to sheet metal's average 25% energy losses, safer with no sharp razor edges to deal with,  and much easier to fabricate and assemble with little expertise or costly specialty machinery or expensive hand tools to purchase. DESCO Energy will design a complete duct system or size any air handling system at no extra charge with the purchase of a complete heating and air conditioning system.

Whether your needs are for your home, business or industrial applications DESCO Energy can provide the best system for you at wholesale pricing. And we'll show you how your new system may be eligible for Tax Credits under the New Energy Bill.

On January 23, 2006 all HVAC manufacturers have been mandated to only produce air conditioning systems with a minimum 13 Seer or Seasonal Energy Efficiency Ratio. Heat Pumps are also mandated for the same air conditioning efficiency with a minimum 7.7 HSPF or Heating Seasonal Performance Factor. 13 Seer line will be the lowest grade equipment produced with the lesser of all warranties. The 2006 Energy Tax Bill will offer tax credit rebates effective for equipment installed on or after January 1, 2006. A $300 rebate will be offered for split system air conditioning systems of 15+ Seer or packaged systems with 14 Seer. There are also tax credit rebates of $50 for variable speed blower motors. Heat pumps with the same 15 Seer air conditioning and 9.0 HSPF are also eligible for a $300 rebate. Gas furnaces with 95% AFUE efficiencies or higher are eligible for $150 Tax Credits while the addition of Variable Speed adds an additional tax credit of $50 for a total of $200. Total tax credits for a single home up to $500 are available for a wide variety of energy improvements. For more details see The Energy Star website.

If you are installing a split air conditioning system in combination with a gas or oil furnace please refer to our Dual Fuel Systems section under Products subsection. 

Packaged systems are designed to heat and cool your home. Your packaged unit may consist of either a heat pump or air conditioner; or a combination furnace and air conditioner called a gas/electric packaged unit.

High Efficiency 90+ Gas Furnace                                               Standard 80% Gas Furnace

Standard Oil Furnace

Below are the items required when installing a gas furnace. The first item in a gas furnace is the size required. Gas furnaces are identified as capacity input and oil furnaces are identified for capacity output. A gas furnace at 100,000 btus can have various heating outputs from 75,000 btus to 95,000 btus depending on the efficiency. It is extremely important to size any furnace on capacity output as this is the amount of heat the furnace produces to the house. The input rating is irrelevant when selecting the proper size furnace. Furnace capacity ranges are identified from 45k, 60k, 70k, 80k, 90k, and 115k btus input for residential applications. It is extremely important to select the furnace not on this size but the output capacity. For example if your heating load as determined by our online Manual J sizing is determined to be 80k btus a furnace of 100k btus input of 100k btus and 80% AFUE will provide 80k btu output and be a perfect selection. But if you want higher efficiency then a 90k furnace at 90k btus input and 95% efficiency will have 85.5k btus output capacity. You can see that the old furnace identification of identification by input heat rating was fine when all furnaces were of the same efficiency. But this antiquated identification system needs to be discarded for the wide varieties of heating efficiencies available today. SEER - Solutions for Energy Efficient Results recommends that no furnace less than 90% efficiency should be used in any application today. 80% AFUE furnaces require expensive chimneys and waste 20% of the energy supplied up the chimney. 80% furnaces have more warranty, maintenance and service problems than the newer hi efficiency condensing furnaces because they're not made as well.

The vast majority of gas furnaces today require a closed combustion system. Most technicians and homeowners mistakenly believe fresh air intake requirements are an energy efficiency feature. However it is required for protection of the heat exchanger, not energy efficiency. A closed combustion system requires both fresh air intake and discharge through pvc or a chimney to protect the furnace. Furnaces many times are located in laundry rooms or in closed basements. Volatile emissions form fabric softener pads or soaps and chlorine bleaches will quickly destroy a heat exchanger when these product fumes come in contact with the combustion flame. To protect the furnace from these types of volatiles including nail polish remover, spray paints or other normal household cleaning agents maximum heat exchanger life is obtained when the air for combustion is taken from outside. Heat exchanger failures caused by volatiles capable of destroying stainless steel heat exchangers are not covered under any manufacturer's warranty. Further there are some home remedies for treating arthritis and other afflictions using chemicals such as DSM which is a dry cleaning fluid. When this chemical comes into contact with a flame it will permeate the metal of the heat exchanger causing a foul rotten egg like odor every time the flame is ignited. The only means of removing the odor is to replace the heat exchanger because it is embedded into the metal. To be safe always use a closed combustion system to protect your new furnace.

When installing you new furnace with a closed combustion system you will either need to make two separate wall penetrations for intake and exhaust air. Using the concentric vent kit eliminates the need for two hole penetrations allowing only one hole penetration creating a more appealing professional appearance. 

While some homeowners may find the cost of installing a concentric vent kit out of their budget the two holes can be made for a closed combustion system and then dressed up with a less expensive decorative vent termination kit. In either option both the concentric vent kit or wall termination kit are substantially more appealing and create a very professional attractive appearance. Nothing looks worse than plastic tubes with various elbow configurations extruding through exterior walls of your home.

The thermostat is the next item required. Thermostats come with many different features and programs today. The newest hi tech thermostats provide a wide array of energy saving features such as every day of the year programming with daylight savings features to monitoring hours of operation with reminders for when to change filters. By slowly raising temperatures at different time periods depending on time required, intelligent energy

 management will raise indoor temperatures according to the recovery time required.  In addition they can also control humidity for humidification while monitoring outside air conditions to prevent condensation of walls and windows. A few can actually control variable speed motors to reduce the air speed for a true dehumidification cycle while others will lower the thermostat cooling setting to provide more dehumidification. Some thermostats are internet ready where they can also be monitored or adjusted over the internet or phone or monitor conditions to send alarms. All this with many more functions or to the simplest electro mechanical thermostats are available. Remember the new two stage gas furnaces with variable speed require hi tech 2 stage thermostatic control to operate efficiently.

Electrical thermostat wire needs to be considered for wiring from the thermostat to the indoor air handler or furnace and then to the outdoor condensing unit. Remember thermostat wiring should never be installed inside conduit or plastic sheathing with power wiring. The new hi tech thermostats can require up to 8 conductors from the thermostat to the air handler or furnace while thermostat wiring from the indoor furnace to the outdoor unit will generally require no more than 3 conductors. When running thermostat wire make certain to always run one or two more leads than required for future changes or a broken wire that may occur.

Vibrations pads and corners are used when the indoor air handler or furnace needs to be mounted to raise the level of the indoor unit or to attenuate noise transmission. Corners are recommended when the air handler or furnace is placed in an upright position on a floor with central return. Vibration pads are primarily used in horizontal mounting positions of the indoor air handler or furnace to attenuate noise transmission. Either corners or vibration isolators are very inexpensive and are worthwhile investments.

For furnace installations in basements or closets in upflow applications, furnace legs make installation easier and provide protection from wet floors or water damage. Furnace legs are inexpensive and make a nice attractive installation.

Humidifiers should be considered an essential part of every furnace installation for comfort and energy savings. No other single item provides more benefits for such a small investment. Winter air is dry air in all parts of the country. Dry air causes drying of skin and respiratory systems. Dry air also supports viruses and related other bacterial growth. For this reason the flu and other respiratory ailments increase substantially in winter months. Dry air dries out hardwood floors and other furniture and construction materials. As well dry air increases static electricity causing computer and other electronic problems and is shocking when walking across carpeted floors. A humidifier increase indoor air quality and comfort eliminating or reducing the problems cause by dry air. A humidifier can allow you to lower the room thermostat setting 3 or 4 degrees without any noticeable comfort change. Even if a humidifier increased your health to the point you were fortunate to avoid catching the flu or a bad cold, the cost of the lost time at work for on illness more than pays for the cost of the humidifier. Add tot his the savings enjoyed from reduced energy consumption there really is no good reason not to install a humidifier with your new gas furnace. The humidifiers of today are much better than ever with low maintenance and better performance. For serious humidification consider the electric heated humidifiers and for standard humidification there is the low cost bypass and injection humidifiers. Consider a humidifier an essential part of your heating system.

All condensing gas furnaces produce water and need to be drained to a sewer line. When a drain access is not readily available such as in a basement or first floor application the use of a condensate pump may be required. Condensate from gas furnaces is drained into the pump reservoir where a float energizes operation of the pump. The water can then be pumped to a local sewer line. Alarm contacts are also provided to deenergize the air conditioning system in the event of pump failure. 3/8" clear plastic tubing is then piped outside or to a local sewer drain. Never drain or pump water from a gas furnace outside as the acid in the water will destroy all vegetation.

The auxiliary drain pan is required when placing a condensing furnace in the horizontal position. Eventually condensate traps will clog unless someone is extremely diligent on constant maintenance. So the attitude should always be when and not if it clogs what damage will occur? In almost all instances horizontal applications are above in an attic area where a condensate trap is not easily accessed for routine maintenance and easily forgotten until they clog. By having an auxiliary drain pan the condensate then flows safely out of the coil on to the auxiliary drain pan and drains safely past the clogged trap. There are also auxiliary drain pans available for vertical or upflow applications. Clogged traps can also result in damaging expensive hardwood flooring or ceilings and floors beneath.

Another protective highly recommended device is the drain alarm. Drain alarms come in two possible applications. One such trap shown can provide an alarm as well as deenergize the air conditioning system until the trap can be safely cleaned. Another senses the accumulation of water build up in an auxiliary drain pan and provides the same protection with an alarm and deenergize the air conditioning system.

Hi efficiency condensing furnaces have special needs and consideration for air filtering. Because of the construction and operation of the furnaces any dirt entering the furnace will actually melt on to the condensing coil. This dirt can't be removed even with steam pressure. Continued build up will result in efficiency losses and premature failure of the furnace not covered under warranty. To protect your furnace and provide continued efficient operation a high media filter is strongly recommended. For proper indoor air quality the air system needs to be properly filtered either using a high media or electronic air cleaner. The high media filter is the most recommended because of higher reliability and visual evidence of proper operation. Electronic air cleaners continue to be less reliable and more expensive to maintain and purchase. Hi Media filter protection is essential to maintaining clean efficient operation of any HVAC system.

In humid climates where mold and mildew are a constant problem the use of an ultra violet lighting system needs to be considered. Ultra violet lighting systems provide the only certain method of controlling and eliminating build up of damaging and harmful fungus and mold spores on wet air conditioning coils.

For customers using propane gas you will require a propane conversion. For single stage gas furnaces this conversion is a simple change of gas orifices. For two stage furnaces the entire gas valve is changed. DESCO Energy will provide the propane conversion for you when requested. We do however advise all customers considering the use of propane gas to reconsider their energy usage. In most parts of the country excluding California the cost of propane gas is more expensive than electric resistance heating. In fact in many parts propane costs 50 to 100% more than electric heat. Ask your technical associate at DESCO Energy about less costly forms of heating. 

Specialty Furnaces

If you are installing a split air conditioning system in combination with a gas or oil furnace please refer to our Dual Fuel Systems section under Products subsection. 

Recommended furnaces

*Eligible for $200 Tax Credit

 Goodman Gas Furnaces 95% 2 Stage Variable Speed

*Goodman GMV95045BXA  45,000 btu 2 Stage Variable Speed Upflow Horizontal

Goodman GMV950704CXA 70,000 btu 2 Stage Variable Speed Upflow Horizontal

Goodman GMV950905DXA 90,000 btu 2 Stage Variable Speed Upflow Horizontal

Goodman GMV951155DXA 115,000 btu 2 Stage Variable Speed Upflow Horizontal

Goodman GCV950704CXA 70k btu 2 Stage Variable Speed Downflow

Goodman GCV950905DXA 90k btu 2 Stage Variable Speed Downflow

Amana Gas Furnaces 96% 2 Stage Variable Speed

*Amana AMV90453BXA  45k btu 2 Stage Variable Speed Upflow Horizontal

Amana AMV90704CXA 70k btu 2 Stage Variable Speed Upflow Horizontal

Amana AMV90905DXA 90k btu 2 Stage Variable Speed Upflow Horizontal

Amana AMV91155DXA 115k btu 2 Stage Variable Speed Upflow Horizontal

Amana GCV90704CXA 70k btu 2 Stage Variable Speed Downflow

Amana GCV90905DXA 90k btu 2 Stage Variable Speed Downflow

The following furnaces are only eligible for the $150 Tax Credit for 95% or higher efficiencies

Goodman GMS95045BXA  45,000 btu Single Stage Multi Speed Upflow Horizontal

Goodman GMS950704CXA 70,000 btu Single Stage Multi Speed Upflow Horizontal

Goodman GMS950905DXA 90,000 btu Single Stage Multi Speed Upflow Horizontal

Goodman GMS951155DXA 115,000 btu Single Stage Multi Speed Upflow Horizontal

Goodman GCS950704CXA 70k btu Single Stage Multi Speed Downflow

Goodman GCS950905DXA 90k btu Single Stage Multi Speed Downflow

The following furnaces are only eligible for the $50 variable speed tax credit

Gas Furnaces

This section assumes you understand about proper sizing, efficiencies, problems in the HVAC industry and how to select a system. In addition there are other very important subjects which are of interest and necessity to properly selecting a gas furnace. If you haven't read the sections under SEER and Solutions we strongly recommend reading the information provided in those areas first.

Gas furnaces use either natural or propane gas. Gas furnaces are identified according to the energy input. For example a 100k btu gas furnace is a 100k btu input furnace. It would make more sense and be more logical to rate gas furnaces for output capacity. No useful information can be derived from the input capacity of a furnace alone. A 100k gas furnace can have 70k, 75k, 80k, and 95k btu output depending on the efficiency. That's quite a variance of capacity ranges for a furnace that is identified the same for all scenarios. A 100k btu furnace 70% efficient has 70k btus output capacity and an 80% efficiency furnace has 80k btu capacity output, a 92% efficient furnace has 82k btus and so on. Why are gas appliances identified as input rather than output capacity? For years gas furnaces all had the same efficiency until the late 1970s when furnace capacities began to increase. Before that time all natural gas furnaces had a 70 to 75% operating efficiency. In the late 1970s and early 1980s gas furnaces were changing to electronic ignition systems and stack dampers. These changes increased efficiencies to 78 to 82%. Until the late 1980s gas furnaces were also continuing to be manufactured with standing pilots at 75% efficiency. It was in the 1980s that condensing furnaces were introduced with efficiencies of 88 to 91% efficiencies. Lennox was the first manufacturer to introduce the Pulse furnace with ultra efficiency furnaces of 90% that condensed the by products of combustion. This first ultra efficiency furnace turned out to be a homeowner's and manufacturer's nightmare but it was the first step towards ultra energy efficiency. The problems that plagued the Lennox pulse furnace were noise, heat exchanger failures, reliability problems and even explosions. Lennox used a spark plug that produced many pulses of electronic sparks per second for ignition. The pulsing was extremely noisy, unreliable, unsafe and had a short term life cycle. Being introduced without sufficient field testing the Lennox pulse furnaces recall was one of the largest recalls in the furnace industry. Today ultra efficiency gas furnaces have become smaller and simplistic in design compared to their initial ancestors. The ultra furnaces of today have higher efficiencies and reliability that exceeds the standard 80% efficient furnaces. The old clam shell welded heat exchanger design used for 50 years has been replaced with simplistic tubular steel increasing reliability and heat transfer. Clam shell heat exchangers were plagued with many manufacturing problems and absolutely every furnace manufacturer has had one recall or another resulting in millions of dollars in costs. Today most 80% gas furnaces have a tubular heat exchanger while condensing furnaces of 90%+ efficiencies use two heat exchangers. Referred to as condensing furnaces the ultra efficient gas furnaces use a tubular heat exchanger and a secondary stainless steel heat exchanger. The secondary heat exchanger extracts most of the energy out of the burnt gases and condenses the by products to water. The secondary heat exchanger resembles an air conditioning coil with stainless steel fins and tubes. When burnt natural gas is cooled the byproducts are primarily water with hydrochloric acid and trace amounts of sulfur. The hydrochloric and sulfuric acids are extremely corrosive necessitating the use of stainless steel to prevent destruction. As the water and acids are condensed out of the burnt gas the furnace has condensate removal piping where the acidic water is drained to sewer systems. This condensate water should never be drained to lawns or areas where vegetation thrives.

Ultra efficient condensing gas furnaces have been constantly improved and refined. Those improvements have now yielded a furnace more reliable than 80% furnaces. The obvious advantage of ultra efficient condensing furnaces is energy efficiency but there are numerous important advantages to using ultra 90+ high efficient condensing furnaces. 80% furnaces require the use of a chimney. They can't be sidewall vented without the use of an expensive side wall vent kit powered with a fan and safety protection costing $400 to $600. Chimneys require constant maintenance and initially are very expensive to install. Without stainless steel liners older chimneys are not safe to use. Continual deterioration requires liners to be installed and replaced on a periodic basis which is also very expensive. 80% furnaces also tend to have more warranty problems and shorter life expectancies. 80% furnaces are not built or engineered as well as ultra condensing furnaces and their warranties are less. There really isn't a justified reason to replace any furnace with an 80% furnace and even less justification or reason to install an 80% furnace in new construction. There are also new tax credits for 95%+ ultra efficient condensing furnaces up to $200.

Many problems had to be overcome in terms of reliability and durability from the original 90+ condensing furnaces to achieve the reliable furnaces produced today.

Original designs had many failures of heat exchangers. Heat exchanger failures were the result of extreme temperature variances that would maximize stress on the weld joints of the clam shell heat exchangers. Premature condensing of gas combustion occurring in the primary heat exchanger caused rapid failures. Some condensing furnaces used aluminized steel and non compatible gasket material in the secondary heat exchangers which also produced subsequent high failure rates. Today manufacturers have learned to use high quality stainless steel with better technology gasket materials resulting in lifetime success of operation and warranties to match. 

In addition a major initial problem that had plagued furnaces was electronic ignition systems that failed continuously. Previous electronic ignition systems failed at the rate of 85% in the first 5 years. Those failures were control circuit boards and igniters or glow coils. Electronic board failures with high voltage coils, electrode or igniter failures and the delicacy of the components made reliability a serious fault. Homeowners were told to always keep spare parts on hand for these components even when purchasing a new furnace. That's bad when you have to stock parts when you just purchased a new furnace! Manufacturers of the gas valves and associated electronic control systems such as Honeywell, White Rodgers, Robertshaw and Penn were all using very different technologies. Manufacturers were constantly changing designs and technologies to create more reliability and endurance. The rapid changes in electronic ignition concepts and design created rapid obsolescence. A simple failure of an electronic control board or igniter usually required a complete change out of the entire ignition system including the gas valve as that particular system was not stocked. Not only was this frustrating but costly too. Most electronic control boards, sensors and igniters only lasted an average of two to three years. Add to this dilemma ignition systems were obsolete in less time. Initially ignition system manufacturers manufactured systems in one unit. Most times the gas valve, electronic ignition control board and relays were all put into one assembly so if one part failed the entire assembly needed to be replaced. Today's electronic ignition systems are of a similar basic principle of operation and parts are compartmented rather than in one assembly making service easier and replacement parts less costly. Reliability has improved to the point of lifetime expectancy for even the igniter coil. Previous igniters were so delicate they couldn't be touched by hands for installation. Imagine trying to install a delicate part you can't even touch. The acid from hands would destroy the surface and etch out a non conductive surface. If the igniter was accidentally dropped it fractured and was destroyed. Today those problems have been eliminated. Igniter coils produce temperatures of several thousand degrees. That's hot. The igniters were energized for 30 to 60 seconds each time the furnace called for heat. Even though the furnace was safely lit after only 4 or 10 seconds the igniter coil continued to glow for the timed out period. Today the timing is based on actual proving the flame is safely lit and no more. There is technology from Norton that measures this time each cycle of operation in a logarithmic computerized system called intelligent igniter technology. The intelligent igniter technology as it's referred to will reduce this time period until the furnace actually fails on ignition. The next cycle the igniter computer will increase the time until it is exactly what is safely required to provide ignition. The goal of the igniter technology is to provide the least amount of time the igniter coil is energized thereby increasing igniter life. Typically the intelligent igniter technology reduces this time of coil ignition time to 4 to 12 seconds compared to the previous 30 to 60 seconds. This reduced firing time of the igniter increases the life expectancy of the igniter coil to a lifetime of trouble free operation without failure. In addition igniter materials of tungsten and nitride are less fragile and can be touched without harm by human hands. That is a remarkable improvement over igniters that typically lasted only 2 to 3 years and ignition boards which would last only slightly longer.

Tappan Is Unsurpassed In Protection Today, Tomorrow, and Always   Tappan Gas Furnaces with SmartLite® Controls Boards provide extended life to igniters in furnaces using hot surface ignition technology. They are programmed to learn the heat-up characteristics of the igniter, then adapt the ignition time to the characteristics of the furnace so the igniter is energized appropriately. Tappan gas furnaces employs hot surface ignition systems (HSI) in our furnace products. These use an igniter which, when energized, rapidly generate an intense heat sufficient to ignite the fuel gas. These systems are safe, well proven, and have a good track record. The SmartLite® Control Board contains a program that varies the igniter heat-up time interval. It learns the heat-up characteristics of the igniter in the furnace by searching for the threshold of ignition failure. It then adjusts the heat-up interval on the next trial accordingly.   This upgrade has been accomplished by microchip software reprogramming. The introduction of this control represents a significant advance in HSI furnace technology.     Tappan control board has a standard 8 year warranty, as do all Tappan heating and cooling products.   All Tappan Gas Furnaces and Gas/Electric Package Units include the SmartLite® Control Board.     Provides extended life to igniters Improved control board contains a program that varies the igniter heat-up time interva     Adapts the igniter time to the characteristics of the furnace     Control accommodates igniter variations by “learning” the heat-up characteristics of individual igniters to ensure reliable ignition, but avoid overheating     Upgrade has been accomplished by microchip software reprogramming and proven circuitry and components     Introduction of this control represents a significant advance in hot surface ignition furnace technology     SmartLite® circuit board printed in blue ink to visually distinguish it from other boards

For the longest time gas furnaces had a one year parts warranty on ignition components. Today technological improvements have increased parts warranties from 1 year to 5 and 10 years and heat exchangers to lifetime from 10 to 20 years. Goodman and Amana have an incredible replacement warranty unmatched by other manufacturers. Goodman and Amana have so much confidence in their new tubular heat exchangers because they have had not one heat exchanger failure in 12 years of manufacturing. Further they have a furnace in their test facilities that has millions of cycles over 11 years without any failure in the ignition system or the heat exchanger. Now that's success! Because of this success they have the confidence to offer a warranty which will replace the entire furnace if there is any heat exchanger failure in the first ten years. For the lifetime of the furnace after the ten year period they will provide a replacement heat exchanger.

If you happen to hear an HVAC contractor or technician bad mouthing any manufacturer of any furnace simply ask them the name of the manufacturer they handle or prefer. Than ask them if that manufacturer has had any massive recalls on their furnaces. If they tell you no, you can guarantee this isn't an honest professional of the industry. The last major recall of heat exchangers was by York on their Coleman and Lux Aire furnaces. Although York was quick to point out this wasn't their furnaces, these are companies owned and produced by York. In the past 20 years York, Carrier, Trane, Lennox, Ducane, Rheem, Armstrong, Janitrol, Goodman, Amana, and Bryant have all had major recalls or heat exchanger replacements in their clam shell designs. In hindsight after looking at the simplicity and ease of manufacturing tubular heat exchangers, it's difficult to understand why clam shell heat exchangers weren't abandoned long ago. It's also hard to believe nobody ever thought of this concept until more recent years. Not only does it make a better product but also substantially decreases the cost of manufacturing. How often does a new idea using cheaper materials and a simpler process make a better product?

Having knowledge of the history of condensing furnaces helps to clear up any misinformation that may still continue from obsolete contractors that never forget. As you can see the problems of yesteryear have improved to a new era of maintenance free hi tech furnaces. But the dinosaur contractors and memories haven't kept up with these improvements and changes. Many times out of touch contractors will remember these problems as though they just occurred yesterday.

Two Stage and Modulation

Another improvement to gas furnaces has been the addition of staging and modulation. Typical furnaces have operated forever at one capacity, 100% or 0%. A car operated in this manner wouldn't be efficient and difficult to control. We don't operate our cars at full throttle and then no throttle. At least most of us don't. A fireplace can produce variable heat output by simply changing the amount of firewood. We don't put as much wood as possible in a fireplace every time we make a fire. In the days fireplaces were used as a primary source of heat the fireplace would have more wood added in the coldest days and less on milder days. That simple technology of variable capacity didn't exist in gas furnaces until recently. Furnace capacity is selected based on the heat required for the coldest winter days. Anytime the outside temperature is warmer than the coldest winter days the furnace is oversized. Like the fireplace with maximum firewood the standard single stage furnace operates the same way. This method of all or nothing is very crude and primitive to try to maintain comfort or save energy.

Two stage furnaces have become more common for many homeowners today. Two stage heating furnaces provide two capacities for increased comfort, efficiency and control. Typically as an example a 100k btu 92% efficient gas furnace will have a first stage of 60% of the total capacity or 60k btus and full capacity or 100k btus on the second stage. Like having two furnaces in one the two stage furnace runs for longer periods of time with more efficiency and less waste. Since the majority of winter temperatures are significantly less than the coldest winter days, the heat requirement is also significantly less. A single stage furnace of 100k btus and 92% efficiency wastes 8% of it's fuel in the stack or flue gases which is 8,000 btus. Every time the single stage furnace is required for heating 8,000 btus go up the stack. However the same furnace with two stages will operate the majority of time at 60% capacity or 60k btus losing only 4,800 btus or almost 1/2 the amount of the single stage furnace. The two stage furnace will also operate for longer periods of time each cycle maintaining higher operating efficiency than the single stage furnace. The single stage furnace will have more short operating cycles in any 24 hour period resulting in more warm up and shut down cycle losses. During start up of any furnace there is fuel wasted as the energy heats the mass of the heat exchangers to achieve operating efficiency. When the furnace shuts off there is the lost heat that wasn't extracted out of the heat exchanger. In addition there is something occurring that doesn't show up on the gas or electric meter which is the wear and tear caused by excessive starts and stops. Frequent start and stop cycles produce extreme wear and tear on the furnace ignition system, motors and blower from start up electrical surges and thermal expansion in the heat exchanger. The more frequent starts and stops not only waste energy but significantly increase wear and tear. Similar to a car that is driven in city conditions with frequent starts and stops and shorter trips versus one that is used primarily on highway miles for longer durations and a constant speed. All other conditions being equal the car driven at highway conditions is always preferred having the least wear and tear. So what are the advantages and energy efficiency gains of a two stage furnace? More energy saved, increased comfort, longer life span and less maintenance. Comfort is increased significantly by providing longer operating cycles of milder discharge air. These longer more moderate heating cycles allow more close temperature control. An additional increase in efficiency by 6 to 15% can be achieved with less start up and shut down cycle losses and less stack losses during the low fire operation. Actual energy savings depend on the climate and efficiency of the house as well as the correct sizing of the furnace to the actual heating requirements. Longer life span is a benefit as the two stage furnace has fewer cycles, less starting torques for the motors, less firing cycles for the ignition system and fewer expansion and contraction cycles on the heat exchangers. That also translates into less service and maintenance required. Hands down for two stage heating being worth the extra investment. The difference in cost for two stage heating is about $100 and will pay for itself in less than one heating season.

As we highlighted the advantages of a two stage gas furnace there are also new hi tech furnaces with modulating gas valves. Modulation produces infinite stages for capacity creating a furnace that is the equivalent of a throttle on a car. Driving a car similar to the operation of a single stage furnace is the equivalent to flooring the gas pedal every time it's operated. Impossible to control and wastes a lot of energy. A two stage furnace is like having a gas pedal that has off, 1/2 throttle and full throttle. Much better to control, higher energy efficiency and substantially less abuse. A modulating furnace is the same as a throttle on a car, excellent to control, maximum energy efficiency and minimal wear and tear.  >From 50% to 100% capacity and anywhere between the modulating gas furnace is the ultimate in heating with a forced air system. Because modulating furnace technology is relatively new, production costs are higher and payback periods are longer than two stage furnaces. At present there are only two manufacturers producing modulating gas furnaces. As more manufacturers produce modulating furnaces the cost will inevitably decline and be more competitive. Modulating gas furnaces are at the cutting edge of new technology and not as cost effective as two stage furnaces. In 2006 and beyond this will change as prices become more competitive. Until then the extra cost of modulation and the smaller benefits derived in comparison to two stage heating do not presently make this feature cost effective. This is not a recommended feature as the payback period is too long and the energy saved is insignificant compared to two stage. There may be a slight improvement in comfort over the two stage operation but this could be considered splitting hairs. A two stage furnace usually provides no more than a one degree deviation in room temperature which is considered near perfect. Could modulation improve this to 1/2 degree and would that be noticeable? Or worth the extra $400? Not recommended at this time by SEER - Solutions for Energy Efficient Results

Variable Speed Motors

ECM Electronically Controlled Motor or variable speed motors, all manufactured by General Electric for every HVAC manufacturer, are without doubt the best and most misunderstood feature of any system. Misunderstood by contractors due to lack of knowledge and experience, this same misinformation has been passed on to homeowners.  Most mistakenly believe the ECM motor varies the speed of the blower motor to change air output from the blower as the need for heating or cooling changes. If you need more heat the blower motor increases the speed of the blower and vice versa. This is not what an ECM motor does. Contractors generally explain the advantages of ECM motors as quiet and inexpensive to operate. Although these are benefits of the ECM motor the primary purpose is to provide constant air flow.  To understand ECM motors they should be called constant air flow motors instead of variable speed. 

Variable Speed Motors

ECM Electronically Controlled Motor or variable speed motors, all manufactured by General Electric for every HVAC manufacturer, are without doubt the best and most misunderstood feature of any system. Misunderstood by contractors due to lack of knowledge and experience, this same misinformation has been passed on to homeowners.  Most mistakenly believe the ECM motor varies the speed of the blower motor to change air output from the blower as the need for heating or cooling changes. If you need more heat the blower motor increases the speed of the blower and vice versa. This is not what an ECM motor does. Contractors generally explain the advantages of ECM motors as quiet and inexpensive to operate. Although these are benefits of the ECM motor the primary purpose is to provide constant air flow.  To understand ECM motors they should be called constant air flow motors instead of variable speed. 

An ECM motor provides a variety of functions providing a wide variety of features and benefits for comfort, efficiency and performance. The ECM motors start very slowly increasing speed gradually until after 60 seconds the blower motor is finally at operating conditions. At operating capacity the blower motor maintains constant air volume by monitoring and maintaining a constant energy consumption. Finally when the system powers down the blower motor will slowly reduce speed until off. The ECM variable speed motor is controlled by varying the voltage to the motor to control speed and maintain a constant load on the motor. By monitoring current consumption the ECM controller varies voltage to maintain a constant wattage or energy consumption. This is achieved by using a Direct Current or DC Motor. Inside the motor control is a rectifier circuit which converts the incoming power from AC or Alternating Current to DC or Direct Current. DC motor control is more reliable, less complex and less costly than AC motor control. The electronic control system varies the output voltage to maintain a constant load on the motor. As the constant load is maintained the speed of the motor varies as the voltage changes continuously. An ECM motor is substantially more energy efficient compared to a standard PSC Permanent Split Capacitor, Split Phase Motor or Capacitor Start Motor typically used on blower motors. An ECM motor consumes 75 watts of energy compared to 500 to 900 watts for other types of more commonly used motors. On average that results in a 90% reduction in energy consumption.

Newer design concepts of energy efficient systems demand longer operating cycles so there is a need to make blower motors more efficient. ECM motors consume less energy to compensate for the longer operating cycles. 

The features and benefits of the first generation of ECM motors were quiet start, quiet stop and quiet operation. The silent operation was a side benefit but the primary purpose of the ECM motor was to maintain a constant air flow efficiently. Standard motors will produce a wide range of air flow variations by only maintaining a constant speed. Standard motors maintaining a constant speed will produces variations in air flow as changes occur. A standard motor is basically designed to achieve a constant speed at the quickest possible start up period and makes no allowance for the variations that can occur in air systems. Variations in air flow occur due to temperature changes of the air - cooler air is heavier and more work is required to move the air while hot air is lighter and easier to move - or from opening or closing of balancing dampers or on diffusers - or filters and coils as they become partially clogged - restrictions in ducting - zone dampers opening and closing or furniture that is placed over diffusers blocking air flow. All these factors affect air flow. As with all HVAC systems the furnace needs a constant air flow to operate efficiently regardless of these changes. Variable speed ECM motors monitor their energy usage and keep it constant by changing speed thereby producing constant air flows.

There are limitations to the ECM motor so if there is too much obstruction or if the duct system is sized too small the ECM motor will begin to surge as it tries to exceed it's limitations of control and speed. In heating systems air flow is extremely important to the efficiency, comfort, reliability, performance and longevity of the furnace. As detailed in our duct design section of our library section we stress how critically important sizing of ducts becomes. A residential blower with a specific sized motor can only move a certain amount of air through a specific size duct. The ECM motor will help to compensate for some of the under sizing that may occur but should not be considered a solution to correcting extremely undersized ducting.

Another feature in ECM motors include a dehumidification cycle that reduces air flow 10% providing true dehumidification. Some hi tech thermostats reduce the temperature setting 2 or 3 degrees lower to achieve a false feeling of dehumidification by artificially forcing the cooling system to run for longer periods of time. The lowering of temperature set point will in most instances only create more discomfort. But ECM motors produce real dehumidification by reducing air flow across the cooling coil removing more moisture from the air. This is what we refer to as true dehumidification.

Another important feature is Auto Comfort Mode. This is a separate new controller developed by Emerson which programs  the start up time period of the ECM blower motor for air conditioning to allow longer time periods to achieve final air flow. Multiple settings from A to D determine the length of time required for the motor to achieve it's operating air flow. A standard blower motor achieves operating speed and air flow conditions in a 3 to 6 seconds. The standard ECM motor achieves air flow in 1 minute. But the ECM motor with Auto Comfort Mode will ramp up to operating air flow in as long as five minutes. This delayed time in achieving operating air flow allows the air conditioning coil to reduce it's temperature rapidly. With Auto Comfort Mode a cooling coil will reach the temperature at which it can begin to dehumidify the air in as little as 2 to 5 minutes. Typically it takes 12 to 15 minutes of operation for the cooling coil to reach cold enough temperatures to effectively remove moisture out of the air. With the Auto Comfort Mode reducing the time to achieve a colder coil for removing moisture allows the cooling system to effectively dehumidify at milder summer days. Light load days almost always produced little to no moisture removal from the cooling system resulting in a cool clammy house. The Auto Comfort Technology incorporated into furnaces accomplishes proper dehumidification in mild days as well as hot summer days.

Life was not always heaven with ECM motors when they were first introduced. Original first generation ECM motors were more expensive and had an unacceptable failure rate. General Electric, the sole manufacturer of ECM motors is a company known to dominate their industries by producing exceptional quality products. General Electric went to work immediately at correcting the problems and failures they encountered from the beginning. Today they produce reliable, quality ECM motors with more features than ever before. For this reason General Electric continues to have high consumer confidence and an impeccable reputation. But as with any problems that occur with new product introductions the bad rumors continue to persist for those HVAC contractors having little or no experience with the ECM motors. ECM motors are only applied in higher more efficient equipment in which many contractors have little or no experience. Often times their fear or negative input are often the result of rumors they've heard or bad experiences from many years ago. Be assured that old rumors and problems of the past seem to never die in the minds of some professionals in the HVAC industry. Whether this is due to the contractors fear of new technology, bad experience or usually rumors, understand that technological changes are not embraced by too many contractors. This is usually due to very limited experience with higher efficiency equipment and more common experience with builder's model systems. New technology comes more of a nuisance to the competitive time factor in installations rather than the benefits to the homeowner.

SEER - Solutions for Energy Efficient Results strongly recommends a variable speed ECM motor for any furnace. The difference in cost is returned the first year in energy savings. ECM motors increase the efficiency of the heating and air conditioning system. An ECM variable speed blower motor not only saves energy but also increase the air conditioning system Seer rating by one point and increases the HSPF efficiency of a heat pump by .3 to .6 points. By maintaining constant air flow ECM motors prevent destruction to the system caused by variations and moderate lack of proper air flow. More constant air flows mean more consistent equipment operation and consistent comfort levels. ECM motors do have limitations and will surge against too small of a duct system or serious restrictions. The surging is a result of the motor attempting to maintain a balance. If the ECM motor surges the problem is a serious obstruction in the air distribution system due to severe under sizing, severely clogged filters or coils or a severe restriction such as fiberglass insulation that has fallen blocking air flow.

ECM motors can also be set up to provide a trim adjustment of + or - 10% of the required air flow, 30 or 70% of normal air flow for ventilation, dual or quattro air flow settings for 2 stage operation and modulating gas furnaces. There are a wide variety of system settings for various air flows for various system capacities available from a single ECM motor. There are presently 3 different horsepower ECM motors for residential applications.

From SEER Solutions for Energy Efficient Results THUMBS UP to variable speed ECM motors. They should be a requirement for any HVAC system you select.

Important Tax Credits

New legislation passed into law effective for 2006 provides tax rebates for high efficiency furnaces. The basics of this legislation provide for any ultra efficient furnace installed after December 31, 2005 is eligible for up to a $200 tax credit. The furnace must have an efficiency of 95% or greater to receive a $100 rebate. Then if the furnace has two stage or modulation and variable speed it is eligible for a total $200 tax credit.

With the tax credit and energy savings benefits of an ultra efficient furnace why would anyone want anything less? 80% AFUE furnaces require a costly chimney or liner or an expensive sidewall vent kit. 80% furnaces waste 20% of the energy supplied, have more warranty claims and after warranty maintenance. All chimneys deteriorate and need constant inspection, cleaning and liners. Chimneys can be unsafe allowing dangerous carbon monoxide gas to enter the house if not properly maintained and lined. Chimney liners can be expensive, time consuming and require constant replacement. 90-93% furnaces are a step in the right direction but more costly without the tax credits. Ultra efficient 95+% gas furnaces with two stage and variable speed cost less to operate and have the added tax credit benefits.

Indoor Air Quality

Essential air filtering required.

Earlier we talked about the need for proper filtration for the new hi efficiency gas furnaces and the need for proper air filtration. When installing any new hi efficiency condensing gas furnace a high media filter should be installed. Any dirt bypassing fiberglass filters will catch on the surface of the condensing heat exchanger and melt. Hold up any fiberglass filter to light and you will see how easy dirt can bypass the filter. Perhaps in one month this amount of dirt may not seem significant but after a few years this cumulative dirt becomes excessive. Also look at the air registers or diffusers and see the dirt that has collected. This is dirt reflective of a poor filtration system. Eventually this dirt will completely destroy the furnace. First it will block the air flow, diminish the efficiency of the furnace and render the furnace useless. The melted dirt can't even be removed by pressurized steam cleaning. SEER strongly recommends installing a new high media filter for any new furnace replacement or installation.

Electronic air cleaners can also be very effective at protecting the furnace however the reliability factor needs to be taken into consideration. Electronic air cleaners are prone to failure and reliability still remains a problem. When electronic air cleaners fail without warning they also destroy the furnace by allowing unclean air to clog the furnace coil.

Humidifiers

Humidifiers are an essential requirement for health, saving energy and protection. Humidifiers add precious moisture to dry winter air. Cold winter air is dry indoor air wherever you live. Even though the weather forecast says the outside air is high relative humidity remember the all important word - relative. Relative means the humidity in the air is the amount of moisture the air can absorb at that specific temperature. Colder winter air is incapable of holding a lot of moisture in comparison to warm summer air. As the winter air is heated to room temperature the relative humidity decreases rapidly. The effect is rapid evaporation of the skin from normal body perspiration. Dry winter air feels colder because it has a higher capacity to absorb moisture from the skin. Not only does the air feel colder to the skin, it is drier. For this reason a thermostat setting of 72 degrees doesn't feel warm in drier air. This drier air also increases respiratory infections and viruses. As the respiratory system dries out it becomes more susceptible to infections and inflammation. Viruses including flu and colds thrive more in drier air. This is why there is a substantial increase in flu, viral and respiratory infections in the winter months. The cost of losing several days of work due to a viral or respiratory infection that could have possibly been prevented from proper humidification of the air is well worth the investment. But the advantages of a humidifier don't stop there. Besides increasing comfort levels permitting room temperatures to be lowered and increased health, humidifiers also eliminate annoying and potentially destructive static electricity and protect building materials such as hardwood floors, antiques and other important articles made out of wood. There is no other single device you could add to a heating system that would provide as many benefits at such a minimal cost. In summary humidifiers save energy, increase indoor air quality and protect your health and house.

Upflow Downflow or Horizontal

UPflow

DOWNflow

HORIZONTAL

Knowing the intended configuration of your furnace is essential. 95% of furnaces are installed in the upflow position where the furnace is placed upright. Air enters the side or bottom of the furnace and is discharged out the top. Horizontal is with the furnace placed sideways as air flows through the furnace horizontally. Horizontal is used when the furnace is in an attic or crawl space. Downflow, a rarely used configuration but commonly applied in modular homes and trailers where ducting is run underneath the house in a crawl space with the furnace in the first floor living area.

Furnaces placed in a horizontal position should have a secondary drain pan. Secondary drain pans provide added protection in the event the condensate line clogs and water overflowing from the furnace collects and drains past the condensate trap.

Downflow furnaces with air conditioning will require extra spacing between the furnace and the coil. This spacer is referred to as a downflow adapter kit. The extra spacing is required to allow the discharge air to spread and dissipate the velocity more equally. Without the downflow adapter kit the air would blow condensate off the coil and into the air stream rather than permitting the condensate to flow naturally to the coil's drain pan.

Important Accessories

For two stage furnaces a hi tech thermostat is recommended. A thermostat providing two heating stages is required. In addition there are thermostats to control the dehumidification of variable speed motors and humidification. Intelligent energy management is a function of hi tech thermostats to efficiently change temperatures during unoccupied and occupied periods with daylight savings time. Ventilation control to allow continuous circulation of the blower at reduced speeds. Automatic changeover from heating to cooling and many other comfort and energy savings features are available. Click on the thermostat link below for complete details.

Installing the pvc venting can present challenges to provide a professional decorative finish. Concentric vent kits provide a single penetration for both the intake and exhaust at one point. All condensing gas furnaces require fresh air intake and exhaust air for a closed combustion system. Many homeowners think the fresh air intake is to save energy. However a closed combustion system is required for equipment longevity. Fresh outside air is required to provide clean burning inside the surface of the heat exchanger. Indoor air is contaminated with pollutants form regular household products like fabric softeners, Clorox and washing detergents. Those products emit vapors that when burned produce corrosive byproducts that can destroy heat exchanger materials rapidly including stainless steel. To protect the heat exchanger and provide maximum longevity a closed combustion system is required.

To assist in the installation of the furnace there are items that can make installations go smoothly. The most noteworthy items are furnace legs, isolation pads, filter racks and return air plenums referred to as labor savers. To learn more about these items see the complete list under accessories below. 

Types of Gas Furnaces

o80%AFUE Gas Furnaces - Single Stage or Two Stage with Standard Blower Motors

                              Two Stage with Variable Speed Blower Motors

Upflow - Horizontal - Downflow

oCondensing Gas Furnaces 93% to 95% - Single Stage or Two Stage with Standard Blower Motors

                              Two Stage with Variable Speed Blower Motors

Upflow - Horizontal - Downflow

Accessories

oThermostats

oOutdoor Sidewall Vent Termination Kits

oConcentric Vent Kits

oPowered Sidewall Vent Kits for 80% Furnaces

oAir Filters - Hi Media, Electronic, Other

oFilter Racks

oLabor Saver Return Plenums with Filter Racks

oHumidifiers - Bypass - Injection - Steam

oFurnace Feet - Isolation Pads

oHorizontal Drain Pan

oCondensate Pumps, Traps, Alarms