Understanding HVAC Speak
Most of us aren’t in the heating and cooling business and probably only pay serious attention to our HVAC systems when there is a problem. At that point, when a contractor is in your home and talking about the pros and cons of several potential units, it becomes clear almost immediately that language specific to the cooling and heating industry is unique. Taking some time now to understand HVAC speak can make a big difference when it’s time to buy a new system.
SEER/EER. This is a rating of the unit that is regulated by the government. SEER stands for Seasonal Energy Efficiency Rating and involves a complex calculation to come up with an energy efficiency rating based on a season of use. The current minimum SEER for new equipment is 13, while it’s possible to find a number of systems rated above 20. The higher the rating, the greater the energy efficiency. EER, or Energy Efficiency Rating, is a similar calculation. However, instead of taking into account a season of cooling with some hot and some mild days, EER calculates a rating based on a peak cooling day.
Compressor, condenser coil. These are two of the most critical parts of an air conditioner or heat pump. The compressor is situated outdoors and pumps refrigerant as needed to cool the home. The condenser coil receives the high-pressure refrigerant from the compressor and releases the heat outside. That allows the refrigerant to cool down, at which point it flows back inside through the condenser coil. The coil works most efficiently when it is clean. A dirty coil can increase the energy consumption of an HVAC system by as much as 30 percent, according to the U.S. Department of Energy.
Payback calculations. This is just what it sounds like and it is information that any HVAC contractor worth hiring can offer a homeowner. The contractor should be able to explain the payback calculations for any unit he recommends. The estimates of what you the of the energy cost you should expect to pay is based on the regional cooling load, the cooling capacity of all units under consideration and the current cost of various types of energy. The payback calculation is one of the ways to compare different HVAC systems against one another.
Programmable thermostat. The thermostat of an HVAC unit controls the temperature inside the house. With a programmable thermostat, it is possible to change the settings during the day – when you might not be home – so that the system is more energy efficient. Some programmable thermostats will work with the Internet so that you can use a computer or cell phone to change settings even if you forgot to do so after leaving on a trip.
Tonnage. This calculation is the one-hour cooling capacity of air conditioners. If a system is 1 ton that is 12,000 Btu’s of cooling per hour. For homes, cooling systems often come in half-ton increments up to 5 tons. One ton can be expected to cool anywhere between 400 and 700 square feet of living space.