Air Conditioning

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. For assistance call us toll free at 877-265-9764 or email info@descoenergy.com

Air Conditioning Systems

Split Systems
15+ Seer
14 Seer
13 Seer
Air Handlers
Variable Speed
Standard Multi-Speed
Coils
Cased Coils
Accessories
Linesets
Disconnects
Thermostats

Mini-Split Systems

Packaged Systems

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.

Air conditioning systems are rated for efficiency and capacity. Efficiency is rated in levels of Seer or Seasonal Energy Efficiency Ratio. Capacity is rated in BTUS or tons. 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 existing air conditioning systems continue to use the reliable R-22 refrigerant while newer more efficient systems use the newest R410a refrigerant commonly referred to as Puron. R410A refrigerant systems now come in two stage compressor operation providing better humidity and temperature control. While the newest state of the art compressors provide variable modulation to vary capacity for a whole range of temperature and humidity conditions. Other energy and comfort features available are variable speed blowers to maintain constant air flows, increase dehumidification, reduce and eliminate blower noise and reduce energy consumption 85%.

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.

Annual savings based on 36.000 Btu unit, 1500 cooling load hours, and .08/kwh. Actual savings may vary depending on climate conditions, energy rates and patterns of usage.

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.

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.

Split Systems

Below are the items required when installing an air conditioning split system. The first item in a split system application is the outdoor condensing unit. Condensing units are rated in capacity and efficiency. The resulting efficiency and capacity are determined in by the correct matching indoor coil or air handler. The capacity ranges from 1.5, 2, 2.5,3,3.5,4 and 5 tons. Efficiency can range from 10 Seer to 18 Seer for cooling. 15 Seer and higher efficiency units use 2 staging and the newer R410A refrigerants. As the efficiency and the capacity increases so does the size of the unit. Important to note the outdoor unit must be at least 18" from any walls and clear of any overhead projections for proper air movement.

A split system installed in conjunction with a furnace will need an indoor coil and this is referred to as a dual fuel system. DESCO Energy only stocks cased coils, meaning there is an insulated wrapper around the coil. If your specific application is to place the coil inside the existing plenum simply remove the wrapper supplied. Removing the wrapper only takes 5 minutes. The difference in cost between a cased and uncased coil is only 4 dollars so rather than stock two different types of coils we only stock cased coils. Coil selection is based on the manufacturers specifications and not on the size of the outdoor unit. For example a high efficiency three ton outdoor unit may require using a 5 ton indoor coil. Today's higher efficiency equipment requires larger coil surfaces on both the indoor and outdoor units. Another factor affecting coil selection is the size opening of the furnace. coils need to be selected to match this size as closely as possible while still maintaining efficiency within the manufacturer's specifications. And another factor affecting coil selection is where you are located. Higher humidity climates require the smaller coils offered by the manufacturer. The smaller coil will produce colder coil temperatures resulting in better dehumidification. For the above reasons it is best to have a NATE certified technical support team member select the matching coil that is best for your specific requirements.

If the split system requires a separate system not involving a furnace there will be an air handler required. The air handler provides both the indoor coil, blower and optional electric heating element. There are two basic types of air handlers. The main difference between the air handlers is that one will use a standard PSC or permanent split capacitor motor with multi speeds. The best air handler is that using a variable speed blower which maintains a constant air flow and provides many other features and energy savings benefits.  Variable speed blowers on air handlers use less energy, provide better dehumidification, provide almost silent operation of the motor with silent start and stop and can be programmed for different air flows based on the requirements of the needs of the specific application.  Variable speed blower motors use less than 1/5 the energy of standard blower motors. And the cooling coils come with TXV control of the refrigerant for more exacting and efficient cooling control.

Electric heat strips are referred to as back up heat, emergency heat and auxiliary heat. The electric heat used is all one in the same. Heat strips come in various capacities measured in kw or kilowatts. The heat output depends on the electric voltage supply at the house. Some areas use 208 volts while others use 240 volts. Heat kit kw is rated at 240 volts and areas with 208 supply power will have a 13% reduction in kw and subsequent heat output. The basic formula of 3.4 btus per watt is the sizing factor for determining the heat required. Heat kits come in 5, 8, 10, 15, 20 and 30 kw packs. Circuit breakers are supplied with each heat kit provided as required by code. Each 10kw of heat requires a 60 amp 240 volt breaker and produces 34,000 btus. 

The picture at left is a light condenser pad. Pads are used in lieu of concrete pads for placement of the outdoor condensing unit. In many instances it may be easier to install a condenser pad with a 5" stone base or no base at all. Where there is a slight grade for the location of the outdoor condensing unit or movement of the soil due to heavy rains or freeze thaw conditions it is highly recommended to use a 4" concrete base with 4" stone base. Remember the outdoor unit needs to be located at least 18" from any exterior wall and free of any overhead obstructions.

This is the refrigeration lineset, which, connects the refrigeration system together from the indoor unit to the outdoor condensing unit. Keeping this length as short as possible is important for maintaining maximum efficiency and performance. The standard linesets come in 30 and 50 foot lengths and in three different sizes. With the small line at 3/8" O.D. copper called the liquid line and the larger line called the suction line with insulation the sizes range from 3/4", 7/8" and 1-1/8" O.D. copper. Longer lengths are available.  The size of the suction line is determined by the capacity of the system as well as the length of tubing lineset involved. 3 ton and over systems use a minimum 7/8" suction tubing for 30 feet or less. For 3 ton and over with 50 ft. lengths of linesets they would use 1-1/8" suction line sizes.

If this is a replacement system and you've chosen not to replace the lineset because it is too difficult to replace, a filter drier for removing harmful acids, debris and moisture must be installed. If it is a liquid line drier it must be biflow. It is highly recommended to always replace the lineset when replacing any air conditioning or heat pump system so you are assured everything is clean and fresh and no residual contaminants will infect the new system. If not a suction and liquid line drier should be installed  of the type for removing acid, moisture and filtering.

For a decorative outside professional appearance a lineset thimble can be used to enhance the penetration required for the lineset. Thimbles are available in round and rectangular design.

The electrical whip and disconnect are the next items needed for the outdoor unit. For every outdoor unit there needs to be an electrical disconnect within sight and reach of the outdoor unit. This is required by all electrical codes in all installations. Most new codes require the use of an electrical disconnect with an electrical 110 volt receptacle attached and ground fault protection or GFI. Standard disconnects come with fused or non fused. It is highly recommended to follow the electrical codes in your area. If a GFI type disconnect is required this can also be handy for any service or another outside source for a plug in connection. At the very least a fused or breaker type weather proof disconnect should be used. The ampacity or size of the disconnect should be no less than that required under the HVAC manufacturer's specifications. Keep the electrical disconnect as close to the outdoor unit as possible.




The electrical whip is a plastic-sheathed protective tube with electrical copper wiring inside. It connects electrical power from the outdoor unit to the electrical disconnect. Electrical whips come in one size and are rated at 240 volts at 60 amps at 6 feet in length.

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. Intelligent energy recovery is essential tot he energy savings accompanied by the use of a heat pump. By slowly raising temperatures at different time periods depending on time required, intelligent energy management will raise indoor temperatures whenever practical without the use of the electric back up heat.  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.

Outdoor thermostats are important additions to heat pumps to provide a changeover in accordance with the balance point. The balance point is where the heat pump capacity due to lowering of efficiency is no longer sufficient to provide the required amount of heating.  The balance point can be anywhere from 37 to 23 degrees outside temperature.

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.

Condensate traps need to be installed in the drain lines of every air conditioning system. Without the use of a trap the negative air pressure inside an air handler or the positive pressure on the coil of a furnace block the natural flow of condensate and result in overflowing of water from the coil. But condensate traps accumulate debris and need to be cleaned at least once annually and in more hot and humid climates once per month. Traps should be installed with screw type unions where they can be easily removed and cleaned. Pouring hot water down the condensate line can be somewhat effective in checking the operation of the trap. But heavy accumulation will inevitably result in build up that blocks the trap.  Being able to remove and effectively clean the trap with warm running water is the best solution. Traps and condensate lines should be a minimum of 3/4" PVC tubing. Copper and steel drain lines should be avoided as they will clog up faster and are more difficult to keep clean.

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 the air conditioning system is drained into the pump reservoir where a float energizes operation of the pump. 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.

The auxiliary drain pan is required when placing an air handler or coil 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.

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.

Protective devices should also be considered for the longest most reliable system performance. If the air conditioning system you are selecting will be operating under unusual circumstances then a low ambient kit should be considered. Low ambient kits provide system protection and efficient operation when the outside temperature falls below 65 degrees.  This type of application occurs in restaurants, computer cooled areas and offices with high heat loads. It can also occur in residential applications where internal areas only are being cooled and the cooling is operating beyond it's design conditions. A low ambient kit cycles or varies the speed of the outdoor fan to maintain a consistent pressure in the refrigeration system essential for efficient operation and protection of the compressor.

Another protective device the hard start kit is used when there is frequent operation of the air conditioning system and/or when there are low power voltages or brown outs. Lower voltages or situations where the refrigeration pressures do not have sufficient time to properly equalize will cause the compressor motor to stall and trip on it's internal overloads creating extreme stress on the motor. Systems using TXVs should also consider the use of hard start kits where undue time is needed for the system refrigerant pressures to equalize. An example of a stalled condition imposed by people can occur by turning the thermostat setting up and down several times quickly. This will cause the compressor motor to stall and trip on it's overloads. With a hard start kit this problem is eliminated and provides extra energy to the compressor motor to overcome problems of insufficient power or rapid cycling substantially increasing compressor life.

A new protective device is also available to monitor and provide added protection to the Copeland Scroll compressors. A very important module which is only available from certain HVAC manufacturers on their highest efficiency models. At the very least the compressor monitor will reduce unnecessary compressor replacements that result from incompetent technicians and contractors misdiagnosing problems. Remember Copeland reports over 35 % of compressors returned under warranty have absolutely no defects and the other 60% are returned with defects that could have been avoided due to improper installations. How many compressors are condemned with no defects out of warranty? You can help avoid this costly mistake and problem as well as provide better compressor protection with the compressor protection module by Copeland.

For packages unit installations the risers, disconnect, whip, electric heat kit, high media filter, thermostat and outdoor thermostats listed above should be the main considerations.

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. 

If you are installing a split air conditioning system with a separate air handler where no systems or ducting exists you will first want to determine the location of the air handler and outdoor condensing unit.  An outdoor unit is only half of a split-system. The air handler is the inside half of the system. Working in tandem, outside and inside units must be matched in size and efficiency for best results. Failing to replace an indoor unit, or mismatching components, can significantly undermine a new air conditioner's or heat pump's performance. An air handler consists basically of a blower, an inside coil, and optional auxiliary electric heating strip. In the cooling mode, as air flows over the indoor coil, heat and humidity are drawn out. It's the air handler's job to then circulate conditioned air throughout the house. Ultimately, performance varies as a result of the blower motor choice.

If your application is in a single story home the best choice for locating the air handler is in the attic area. By locating the air handler and ducting in the attic the cold air will fall from ceiling diffusers and provide excellent comfort. If there is no attic available or accessible the air handler and duct system can be run in the living area. The duct system can be installed in a bulkhead which can later be enclosed in drywall. A last resort would be to locate the air handler and duct in a crawl space. The air handler could also be located in the living area while the duct work is in the crawl space area. The problem associated with this type of installation is the simple rule that cold air falls and comfort levels will not be as satisfactory. Floor feeding registers for air conditioning always produce comfort problems as the room air at a 6 foot level is always 8 to 15 degrees warmer than the floor temperature.  Air handlers should not be located in garages that are not living areas or have ducting supply or return air form garage areas. Garages have a 2 hour fire code separation in most homes built since the late 1980s. The purpose of the fire block is to prevent a fire form spreading from the garage to the house. Even if your house does not have this fire separation and even if the existing air handler or ducting is located in the garage area, the replacement system should not violate this valuable fire protection. A fire ignited in a garage with a tank of gas is like a bomb and will move even faster if fanned by an air handler or can easily migrate through the house via a duct system. Further if there is a fire and subsequent investigation determines the spread of the fire was due to a code violation the insurance company will generally not honor the claim especially when that violation was a result of a homeowner's do it yourself project.

On a two story home life becomes more challenging when installing any type of ducted heating and/or air conditioning system. Certain parameters need to be followed in order to make the best decision. SEER - Solutions for Energy Efficient Results has established guidelines for installing any forced air HVAC system on a two story house. First a determination needs to be made if a single system or two systems should be used. Before you cringe about the idea of two systems read this first. Many times two systems are less expensive to install compared to one system with zone dampers. With two systems there is less labor and material for ducting. There is also less labor installing two systems over one. There is no recommendation being made that all two story homes should have two systems but there are guidelines for when they should be considered:

If the total cooling load for the house is 3 tons or more.

If your house is over 1,800 square feet.

If there is an open stair case to the second floor.

If there is a vaulted ceiling to an open second floor area.

If the existing system provides intolerable temperature variations between floors

 If comfort is a priority.

If maintaining consistent temperatures is important.

If maximum energy savings are your goal.

If having at least one operable system eliminates the need for an emergency service call if the other system fails.

If you want cooling on one floor without having to overcool the other floor.

If you want heating on one floor without having to overeat the other floor.

If having cooling on one floor and heating on the other floor when required.

If there are substantial differences in construction style from one floor to the other - Eg. First floor has large glass areas and vaulted ceilings and second floor has lower ceilings and low glass exposure.

The most important part of any air conditioning system beyond the equipment is the duct or air distribution system. SEER - Solutions for Energy Efficient Results Strongly recommends the use of fiberglass ducting. Fiberglass duct board is the easiest most efficient reliable product on the market. In comparison to sheet metal ducting fiberglass ductboard is less expensive and requires less labor to install than equivalent sheet metal ducting with fiberglass insulation. Fiberglass is more efficient because it doesn't leak air and is totally silent. Fiberglass attenuates noise created by air movement and noise created by the motor and blower. Sheet metal ducting accentuates noise making for a louder operating system. But you can't find fiberglass ducting everywhere.

Benefits Of Fiber Glass Air Duct Insulation Products In An HVAC System

As key components of a well-designed, operated and maintained HVAC system, fiber glass air handling insulation products improve the overall quality of the indoor environment. These materials not only provide cost-effective delivery of indoor environmental quality, they conserve energy, maintain air temperature, and control noise and condensation.

Energy Conservation

The insulating role of fiber glass duct board, duct wrap and duct liner has become even more important with the increased emphasis on ventilation. Increased ventilation requirements place more demands on a building's energy source. The importance of energy efficiency is increasing in terms of overall energy conservation and the affordability of increased ventilation.

Consistent Air Temperature

By reducing the heat transfer across the duct system, fiber glass insulation products allow a building's HVAC system to deliver conditioned air at design temperatures. Consistent air temperatures mean increased comfort for building occupants without over-taxing the energy source, while maintaining lower energy costs.

Noise Control

Without fiber glass insulation products, the acoustical environment of mechanically conditioned buildings can be greatly compromised. Fiber glass duct board and duct liner reduce the transmission of HVAC noise through the duct system, such as expansion and contraction of steel ducts (popping and cracking), air turbulence, etc. Fiber glass acoustical insulation also reduces noise transfer (cross-talk) from one room to another through the ducts.

Condensation Control

Fiber glass duct liner, wrap and board help control condensation in air conditioning duct systems, reducing the opportunity for microbial growth. Condensation will form on bare sheet metal air-conditioning ducts at any point at which the duct surface temperature reaches the dew point. The moisture may remain in place or drip, causing moisture damage and creating a potential for microbial contamination. Fiber glass insulation corrects this problem by reducing moisture occurrence, thus eliminating a precondition for microbial growth.

House Additions

If you are planning to add an addition or the addition is already completed, treat the addition area as separate. Additions are almost always with higher insulation value and more energy efficient than the main part of the house. As a result the cooling and heating load requirements for these areas will be entirely different than the main part of the house.

To properly provide comfort to any of the above conditions a heating and/or cooling system must have zone dampers with proper control. The zone dampers or zoning will also require the dampers to either bypass the extra air back to the air handler when closed or a two stage heating and/or cooling system or both. Two stage air conditioning systems and zone damper systems are expensive. In fact so much more the additional costs are more than two separate systems. Two stage systems with zone dampers and a long duct system that stretches to cover all areas takes more space, requires more materials and labor and adds to the overall costs. Zoning systems without two stage compressors for the cooling system are a perfect recipe for premature equipment failure. Air conditioning systems require critical constant air flows. Typical zone dampers simply open and close air supplies with no regard to the effect on the overall air capacity required. For example a 3 ton air conditioning system requires 400 cfm - cubic feet of air flow per minute per ton or for three tons - 1,200 cfm.  Zone dampers controlling an equally proportioned two story house would be placed to block air flow to the first floor when no cooling is required in that zone. That would reduce the air flow by 50 to 60% in the main system or reduce air flow to 600 to 720 cfm of air. That reduction in air flow would cause serious harm to the air conditioning compressor and result in excessive noise in the air diffusers in the second floor as the extra air capacity is attempting to be forced out fewer air diffusers. A two stage air conditioning system would automatically reduce the air flow as required when the zone dampers were closed. The damper control system would send a signal tot he air conditioning system to cause this reduced air flow and lower operating speed of the compressor thus causing no harm. This is just one example of why zoning and two stage air conditioning systems are a better more expensive choice than one single stage air conditioning system. But the ultimate less expensive solution is two separate systems. The other advantage to using two separate systems on two story applications is the ability to run different ducting systems. The first floor system is usually floor fed while the second story system is ceiling fed. Stratification that migrates from the first floor heating system will then have less effect to the second floor conditions. The second floor air conditioning will also migrate to the first floor with a minor effect.

Most homeowners rarely consider the need for two systems nor the benefits. Usually the thought is to accomplish everything with a single system. But realizing stratification and the role it plays in comfort there are many huge beautiful houses with large vaulted ceilings and open stair cases where dual systems or zoning was never considered. The end result is a house that is so unbearable the occupants can't sleep comfortably or to accomplish proper comfort on the second floor the first floor becomes unbearable.

If your application is new construction or renovation now is the time to consider all possible options for comfort and efficiency. After the house is completed the cost to correct HVAC mistakes becomes very pricey. 

After a determination has been made for the size and number of systems required and the location and layout of the air handlers is selected, the next process is to locate the outdoor or condensing units. The closer the distance the air handler is to the outdoor unit, the more efficient it will operate. The  vertical distance has the greatest impact on efficiency. Typically line sets for connecting the refrigerant lines are 30 feet and 50 feet.  It is strongly recommended to keep the line set as short as possible and not more than 75 feet. Location of the outdoor unit should also consider  the solar effect. Placing an outdoor unit in direct sunlight is the least favorable of all locations. An ideal location for an outdoor unit should be placed no closer than 18" to the wall of the house with no obstructions overhead and on a north wall less than 30 feet from the air handler. That would be a perfect location in a perfect world. Now if the decision to place the outdoor unit 70 feet away to simply locate away from the solar gain would not be the best decision. However of you live in the hot dessert conditions similar to Arizona, placing the outdoor unit out of the sun would be a top priority.

After the indoor air handler and outdoor unit have been properly located the next step is to layout the duct design. Ducting and it's design can be found in our Product subtitle. If you are having difficulty laying out the duct design or would like a review of your design or existing system, DESCO Energy provides a basic layout and sizing of any duct system upon purchase of a heating and/or air conditioning system. We understand that sizing and design of duct systems can be overwhelming so we will take that problem away at no charge at your request.

Homeowners sometimes request a complete review, sizing and selection and layout of the system. Again we will provide all these services to you. Those services are part of what we do for every customer that requests them.

Selecting the right system with the best efficiency. Realize you're already way ahead of the process of your heating and air conditioning system by making it a do it yourself project. What most homeowners want is the best value for their money. After all that's the motive behind do it yourselfers. Do it yourselfers want to save as much money as possible but not at the expense of having shoddy equipment or a shoddy installation.

Packaged units generally lack many of the higher efficiencies and features of split systems. For most homeowners packaged units and accompanying exposed ducting is unsightly and requires constant maintenance. Most packaged systems are usually used in areas where labor and trained installation technicians were difficult to find. Rarely are packaged systems used in new construction unless the design of the house lends itself for an easy packaged installation. The ease is a result of being able to place the ducting under the crawl space and the unit is designed to sit on a slab outside the house in a location not readily viewed. Packaged systems in residential applications are usually installed on one story homes due to the ducting restraints.

Packaged units are usually offered in two efficiency ratings from most manufacturers, the minimum and one step above. Packaged systems are easier to install  but generally have a shorter life expectancy. We strongly believe the shorter life expectancy is due to improper design and installation of packaged systems. Many times homeowners in the attempt to save as much money as possible will purchase a packaged system to avoid the use of a licensed professional installer. Without any outside assistance the duct system is installed without proper sizing and distribution and with insufficient duct insulation. These factors are sufficient reason why packaged units have such a high failure rate. The installation also becomes a less than satisfactory job and the net result is short life expectancy. Packaged units can work well and have proven reputation of excellent service and longevity on commercial applications on rooftop installations. Perhaps the reason commercial packaged units last longer than residential systems is due to the fact that almost all commercial applications were designed and installed according to engineering standards. A packaged system can work for you if the unit is installed and designed correctly. And most importantly if the house design lends itself to the installation of a packaged unit which most do not.

If a packaged system wasn't in your plans then a split system of 14 Seer o more should be selected. 15 and 16+ Seer systems are mostly two stage and use the new R410 refrigerants. The outdoor units of today are larger than ever as large coil surfaces are required to achieve high efficiencies. Two stage systems are new and there is a premium price for these. As mentioned previously a two stage system with dampers is more expensive than two separate single stage systems. But there are other benefits to using two stage systems. The primary benefit is dehumidification. Two stage compressors are not going to be as popular in the Southwestern parts of the country as they will be in the North and Southeast areas. Dehumidification during light or milder summer days has always been a problem with air conditioning systems. Air conditioning systems are sized, selected and designed for the hottest summer days or an average of 95 degree outside ambient. At this condition the air conditioning system  will operate for long cycle periods. A well designed system will operate at 70 to 75% of the time at it's design temperature. But most summer days are not at those temperatures. Because most summer days in most parts of the country are in the 80s the air conditioning systems are oversized for those days. The net result is the system only operates for 30 to 40% of the time. This shorter time period doesn't permit the system to operate long enough to allow the cooling coil to get cold enough to draw moisture out of the air. The net result is a house that produces a cool clammy environment.  But if the system was smaller it would operate longer during those mostly milder days. And that's exactly what a two stage air conditioning system does, it operates for the same length of time as it did when it was hot outside providing enough time to satisfactorily create a cool dehumidified environment. The age old problem of cool clammy has been resolved with a two stage air conditioning system. And that's is what is so great about two stage air conditioning systems.

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.

Packaged units generally lack many of the higher efficiencies and features of split systems. For most homeowners packaged units and accompanying exposed ducting is unsightly and requires constant maintenance. Most packaged systems are usually used in areas where labor and trained installation technicians were difficult to find. Rarely are packaged systems used in new construction unless the design of the house lends itself for an easy packaged installation. The ease is a result of being able to place the ducting under the crawl space and the unit is designed to sit on a slab outside the house in a location not readily viewed. Packaged systems in residential applications are usually installed on one story homes due to the ducting restraints.

Packaged units are usually offered in two efficiency ratings from most manufacturers, the minimum and one step above. Packaged systems are easier to install  but generally have a shorter life expectancy. We strongly believe the shorter life expectancy is due to improper design and installation of packaged systems. Many times homeowners in the attempt to save as much money as possible will purchase a packaged system to avoid the use of a licensed professional installer. Without any outside assistance the duct system is installed without proper sizing and distribution and with insufficient duct insulation. These factors are sufficient reason why packaged units have such a high failure rate. The installation also becomes a less than satisfactory job and the net result is short life expectancy. Packaged units can work well and have proven reputation of excellent service and longevity on commercial applications on rooftop installations. Perhaps the reason commercial packaged units last longer than residential systems is due to the fact that almost all commercial applications were designed and installed according to engineering standards. A packaged system can work for you if the unit is installed and designed correctly. And most importantly if the house design lends itself to the installation of a packaged unit which most do not.

If a packaged system wasn't in your plans then a split system of 14 Seer or more should be selected. 15 and 16+ Seer systems are mostly two stage and use the new R410 refrigerants. The outdoor units of today are larger than ever as large coil surfaces are required to achieve high efficiencies. Two stage systems are new and there is a premium price for these. As mentioned previously a two stage system with dampers is more expensive than two separate single stage systems. But there are other benefits to using two stage systems. The primary benefit is dehumidification. Two stage compressors are not going to be as popular in the Southwestern parts of the country as they will be in the North and Southeast areas. Dehumidification during light or milder summer days has always been a problem with air conditioning systems. Air conditioning systems are sized, selected and designed for the hottest summer days or an average of 95 degree outside ambient. At this condition the air conditioning system  will operate for long cycle periods. A well designed system will operate at 70 to 75% of the time at it's design temperature. But most summer days are not at those temperatures. Because most summer days in most parts of the country are in the 80s the air conditioning systems are oversized for those days. The net result is the system only operates for 30 to 40% of the time. This shorter time period doesn't permit the system to operate long enough to allow the cooling coil to get cold enough to draw moisture out of the air. The net result is a house that produces a cool clammy environment.  But if the system was smaller it would operate longer during those mostly milder days. And that's exactly what a two stage air conditioning system does, it operates for the same length of time as it did when it was hot outside providing enough time to satisfactorily create a cool dehumidified environment. The age old problem of cool clammy has been resolved with a two stage air conditioning system. And that's is what is so great about two stage air conditioning systems.

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 heat pump air handler 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.

Slower start up of the ECM motor also provides benefits to the cooling and heating cycles of heat pumps in different ways. During the cooling cycle the slower time period allows the cooling coil to reach lower temperatures faster providing better dehumidification during mild summer days. For heating cycles the heating coil has more time to produce heat thereby eliminating cold blasts of air so often accompanied by standard heat pump blower motors. 

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 air conditioning system. 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 increases 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 heat pumps. 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.

Another important component of all air conditioning and heat pump systems is the compressor. The Copeland Scroll compressor is the number 1 compressor used by most major HVAC manufacturers today. The compressor is the heart of every heat pump. The Copeland Scroll compressor utilizes a more efficient design rather than the typical piston reciprocating compressors. Because of it's efficient operation, proven 15 years of reliability the scroll compressor now dominates the entire HVAC market. The scroll compressor is not only efficient but much quieter than previous reciprocating compressors.

With HVAC manufacturers using the same components today for all their systems is there really a big difference between manufacturers? With blower motors using variable speed all made by General Electric, scroll compressors mostly made by Copeland and reversing valves, copper tubing, aluminum fins and contactors and relays all supplied by a few manufacturers there is no real difference between manufacturers except in terms of price, support and warranty.

Important Rebates & 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 $150 rebate. If the furnace has variable speed it is eligible an additional tax credit of $50 for a total $200 tax credit.

There are tax credits available for higher efficiency split heat pumps and air conditioners with a 15 Seer efficiency rating and 9.0 HSPF for heat pumps or 14 Seer for packaged systems. Tax credits of $300 are available for these systems.

In many areas utilities may offer rebates for higher efficiency equipment. Check with your local your local electric utility for possible rebates on heat pumps.

Indoor Air Quality

Essential air filtering required.

Earlier we talked about the need for proper filtration for the new hi efficiency heat pumps and the need for proper air filtration. When installing any new hi efficiency heat pump a high media filter should be installed. Any dirt bypassing fiberglass filters will catch and build up on the surface of the indoor coil. 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 heat pump. First it will block the air flow, diminish the efficiency of the heat pump and if left unchecked will destroy the compressor. SEER strongly recommends installing a new high media filter for any new heat pump replacement or installation.

Electronic air cleaners can also be very effective at protecting the heat pump 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 heat pump by allowing unclean air to clog the furnace coil.

Humidification

A humidifier should be considered an essential part of any heat pump replacement or new installation. Earlier we highlighted the problem of the low discharge air temperatures common to heat pumps. Also the discharge temperature decreases as the outdoor temperature decreases increasing discomfort. Cooler direr air as the outside air temperature decreases is not conducive to indoor comfort.

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.

Heat pump humidifiers must be of the electric heated steam generation type to be effective. Bypass and powered filters do not produce anywhere near rated capacities due to the colder discharge air temperatures. Also bypass humidifiers upset heat pumps critical air flow requirements and can cause harmful air recirculation.

Upflow Downflow or Horizontal

Knowing the intended configuration of your indoor air handler is essential. 92% of air handlers are installed in the upflow position where the furnace is placed upright. Air enters the bottom of the air handler and is discharged out the top. Horizontal is with the air handler placed sideways as air flows through horizontally. Horizontal is used when the air handler 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 air handler in the first floor living area.

Air handlers 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 collects in the drain pan and drains past the condensate trap.

Important Accessories

For air conditioning systems a hi tech thermostat is strongly recommended. A thermostat providing control of 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.

To assist in the installation of air conditioning systems there are items that can make installations go smoothly. The most noteworthy items are air handler 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 and ducting.

In summary SEER recommends six important components for every air conditioning application - 14 Seer or higher efficiency - variable speed blower motors - hi tech energy management thermostat - high media filter - scroll compressor