Have you ever read a certain word or an abbreviation on an HVAC company’s website or brochure and had trouble knowing it’s exact terminology? We wanted to provide a glossary of sorts for our customers on some terms we thought could use some explanation! If you think there is a term missing or one you’d like to know more about, please contact us!



Annual Fuel Utilization Efficiency. A rate of measurement which shows how much a gas furnace coverts fuel to energy. An AFUE of 80 means that 80% of the fuel is being used to warm your home while the remaining 20% is escaping as exhaust.


British Thermal Unit. 1 BTU = the heat from 1 wooden match. BTU is a measurement of energy needed to raise 1 pound of water 1 degree Fahrenheit. It represents the amount of heat energy in your home when burning fuel or the amount of heat energy extracted while cooling your home.


Comfort Enhancements. Any piece of HVAC equipment or technology that enhance the comfort of your home, i.e. Thermostats, Dehumidistats, Dehumidifiers, Humidifiers, Heat Pumps, Air Filters, etc.


A dehumidistat is a device which controls the humidity levels in the home by communicating with the thermostat to change the temperature. Click HERE to learn more about Dehumidistats


The First Law of Thermodynamics defines Efficiency as the ratio of work or energy output to work or energy input that cannot exceed 100 percent. When your AC unit is preforming below high or maximum efficiency you are losing money! Click HERE to learn more ways you can get the most out of your AC

Filter (Air)

A relatively small screen/pleated paper/spun fiberglass sheet that, when placed correctly into an AC unit, catches contaminates and pollutants cycling through your unit ensuring clean and purified air is entering your home (as long as the filter is changed/cleaned regularly). Click HERE to read more on why Air Filters are vital to your AC unit.

Geothermal Heat Pump

A heat pump that uses ground water, lakes/ponds or the ground as heat sources or heat sink vs. the conventional heat pump which uses outside air. The Ground and water in ponds both hold more consistent temperatures throughout the seasons, warmer temps. In the winter and cooler temps. In the summer. Click HERE to find out whether you should invest in an AC unit or a Heat Pump.


Heating, Ventilation, and Air Conditioning. HVAC is the technology behind indoor comfort with the goal of providing thermal comfort, and good IAQ.


Indoor Air Quality. The quality of air that your AC unit is pumping into your home. The IAQ has a lot to do with the unit’s air filter and other indoor variables such as children, pets, and the use of air fresheners. Click HERE to learn more about IAQ and find out what your IAQ is.


When you use Tri County Air, your neighbors and visitors will be super jealous once your crisp AC and amazing IAQ hits them!


You know your air condition better than anyone. It’s important to keep an eye out for any irregularities concerning your unit. Watch for spikes in temperature (low or high), humidity and the cost on your energy bills. If you ever notice a problem with your system, please give us a call!

Load / Load Calculation

A Load is the amount of power needed to run a circuit or system such as a refrigerator or an air conditioner. A Load Calculation is the assessment of the discrete components that make up a load, usually including the time of day and season as a variable.


Minimum Efficiency Reporting Value, this is simply a rating of effectiveness of an air filter. There are many different kinds of air filters and each kind will have an effect on your unit and your air quality. It’s important that your unit is matched up with an appropriate MERV rated air filter, because if the MERV rating exceeds what your unit can handle the filter will suffocate your unit over time. It’s best then to have an HVAC professional take a look and let you know the correct caliber of filter you need!


What you should say to any other AC company besides Tri County 🙂

Outdoor Coil

The heat exchange part of a heat pump. It collects heat when the pump is in ‘heating mode’ and or expels heat when the pump is in ‘cooling mode’.

Packaged Unit

Just as the name hints, this unit is a packaged deal. Most homes have an air handler alongside an air conditioner. However, manufactured homes or mobile homes don’t have room for both of these pieces of equipment, so they are combined into one large unit to be placed outside the home for convenience and space.

Quiet Operations

Noisy A/C units can be pretty irritating, it’s important to know when purchasing a unit how loud it is going to be. Noise is measured by dB’s (decibels) so once you find out your unit’s decibel number, you can determine if the noise level will be acceptable.

50 dB: a quiet conversation between to friends

60 dB: a conversation in a restaurant

70 dB: the average house-hold vacuum cleaner

80 dB: the average house-hold disposal


A substance that produces a cooling effect used mostly in air conditioning and cooling systems.


Seasonal Energy Efficiency Ratio. This rating measures the cooling efficiency of an air conditioner or heat pump. The higher the SEER rating, the more efficient the unit!


Tonnage is the cooling capacity of an air conditioning system. One ton is equal to the amount of heat required (288,000 Btu) to melt one ton of ice in a 24-hour period.

UV Light

UV lights have all sorts of uses. They can treat tuberculosis, sterilize water and now we also use them to kill mold, bacteria, germs and odors in your A/C systems!

Variable Speed Motor

An indoor blower motor inside of a furnace, which moves at different speeds to precisely control the flow of heated and cooled air throughout your home.


Windows play a big part in your homes indoor temperature. There are different types of glass that can prevent the sun from over heating your home forcing your AC unit to work harder to cool down your home. There are also certain types of curtains that can help block out those sometimes-too-invasive sun rays!

eXcellent service 😉

 Exactly what you get when you let Tri County Air service your every AC need!


Probably the most important factor in the HVAC business believe it or not. Your comfort is our first and foremost priority. You understand your AC’s habits better than anyone, and when something goes awry you ar the first to know! Tri County understand the importance of at-home comfort, and wants to make sure that when you use our services you are beyond satisfied.

Zoning System

Zoning systems are used to cool or heat certain “zones” of your home. Think of “zoning” as dividing your house up into different sections. One air conditioning unit is programmed through a control board to cool and or heat the specific room that you are in. When you turn on the sink, turning on that specifc sink does not automatically turn on all of the sinks in your house — just like when you turn on the AC in one of your home’s “zones” it does not automatically turn on your entire home’s AC.