System Efficiency

This page is designed to give you a little knowledge of air conditioner and heating efficiencies.

Air Conditioner Efficiency

Desert Tech, Inc. uses the term Seasonal Energy Efficiency Ratio (SEER) when describing the efficiency of an air conditioning system. In short, the higher the number of SEER, the more efficient the system.

The federal government had instituted standards requiring manufacturers to make systems more efficient. In 1992, a law was passed requiring all systems to be a minimum of 10 SEER. Beginning in 2006, a new law now requires all systems manufactured to be a minimum of 13 SEER. Simply put, a 13 SEER system used 1/2 the electricity of the 6.5 SEER which was available prior to 1992. There are systems that reach over 20 SEER. The investment in a higher SEER is worth the energy efficiency.

If you have a new system installed, chances are it will be more energy efficient that what you currently have, Your overall savings will be dependent of the total cost of electricity, weather, and usage.

Heating Efficiency

When looking at heating efficiencies, don't be confused. You need to take into consideration the cost of fuel versus the amount of heat the system produces and the efficiency of how well it uses this fuel. An electric furnace is effectively 100% efficient, but the cost of an electric hearer can be 3 times the cost of a gas furnace due to the cost of electricity versus gas.

Heat Pump Efficiency

Heat Pumps use a heating efficiency rated call COP or Coefficient of Performance. The higher the COP, the more cost effective the heat pump is at producing heat. Heat pumps use the reverse cycle of an air conditioner to produce very efficient heating costs.

Gas Efficiency

Systems that use either natural gas or propane for heating are rated using the term AFUE or Annual Fuel Utilization Efficiency. The AFUE is used to determine how much of the heat actually ends up in the house vs. how much ends up outside.

When gas is burned, it creates a certain amount of heat. Any burning fossil fuel also produces combustion byproducts that need to be exhausted to the outside. Manufacturers have designed systems to reach efficiencies of 95% and more by limiting the amount of heat that escapes with the flue gasses.

Gas furnaces designed before 1992 had efficiencies as low as 50%. After 1992, standards have been set to 78% efficiency. An 80% to 90% efficient furnace is common in today's homes.

Multi-Stage Burners

Systems are now available with gas fired units that adjust the amount of heat produced by the system based on the amount required. If the weather is mildly cold outside, the burner will burn less gas allowing the unit to run longer as opposed to short cycling by turning on and off frequently. Multi-stage burners increases the cost effectiveness and comfort provided by the system.

Variable Speed Blowers

Until recently, most blowers (fans) in furnaces were either all the way off or all the way on. This causes an uncomfortable movement of air when the furnace or heat pumps first start up. New variable speed technology slowly increases and decreases the blower speed as needed for maximum comfort.

Additionally, a benefit of the variable speed blower is its ability to continually move the air. If you have a central air system or air purification system, you can't clean the air unless the system is on. A variable speed system allows the air to circulate when heating or cooling isn't required. It also speeds the system up when necessary, allowing for the most effective use of an indoor air quality system.