How your air condition works

Your indoor unit moves air across the indoor evaporator coil, and heat is absorbed into the refrigerant in the coil. The refrigerant is then circulated outside, where the heat is exhausted with a fan blowing across the outside condenser coil. As strange as it may seem an air conditioner doesn’t “add” cool air; it removes heat from the air.

Load Calculation

A series of studies performed to determine the heating or cooling requirements of your home. Most load calculations today are performed with some type a software program. An energy load analysis uses information such as the square footage of your home, window or door areas, insulation quality and local climate to determine the heating and cooling capacity needed by your furnace, heat pump or air conditioner.


The part of an air conditioning system that pumps refrigerant through the system by increasing the refrigerant pressure. Located inside the condenser. It is the heart of the air conditioning system.


Seasonal Energy Efficiency Rating. This is the term that is commonly used to identify how efficient an air conditioner is at using electricity. In 2015, The Department Of Energy passed a law requiring all systems to be 14 SEER or better (the higher the number the more efficient the system). 20+ SEER systems are available currently today, but are priced accordingly.

Air Conditioning Condenser

Air Conditioning Condensers are the outside portion of a “ Split” system air conditioner. The Condenser is typically connected via copper tubing to an Evaporator Coil that is located in the Air Handler or in combination with some type of Furnace. An Air Conditioner uses refrigerant (commonly called Freon), circulated through the system using a compressor. The heat from the home is absorbed into the refrigerant and transferred to the outdoor unit. This is why you can hold your hand over an outdoor unit in the summertime and feel it blowing out hot air.

Heat Pump Condenser

Heat Pump Condensers are the outside portion of a “ Split” system Heat Pump. The Condenser is typically connected via copper tubing to an Evaporator Coil that is located in the Air Handler or in combination with some type of Furnace. Heat Pumps work exactly the same way as an Air Conditioner in the summer, but reverse their operation in the winter. As strange as it seems, even down to about zero degrees Fahrenheit outside, a Heat Pump can capture heat from the outdoor air and transfer it via the refrigerant to the indoor conditioned space.

Evaporator Coil

The Evaporator Coil is the indoor portion of an Air Conditioner or Heat Pump system. The Coil usually is not visible, but is placed somewhere in the air stream of a ducting system, usually very close to the furnace or air handler. The Coil is connected to the outdoor unit via copper tubing and normally you can see where these tubes attach to the inside unit.

Air Handlers

An Air Handler is the indoor portion of a “Split System” air conditioner when the air conditioner is not using a furnace as its air moving system. The air handler is simply an electric furnace that includes the air conditioning evaporator coil inside. Air handlers might also be referred to as an electric furnace. An air handler or electric furnace usually can be identified by not having a flue pipe (chimney or exhaust) that is used with a gas or oil furnace. Air Handlers that also provide heat from electric coils normally have a large electric circuit feeding them, anywhere from 30 to 120 amps.

Variable Speed Air Handlers

This isn’t a separate type of air conditioner, but rather an alternate means of moving the cool air around. In a standard forced-air system the air handler operates at full blast, delivering air into the home at 100 percent capacity, turning off when it reaches the desired temperature, then activating again when needed. A variable speed unit starts at full speed in the morning to quickly establish a comfortable temperature, then slows down but continues to operate continuously through the day to maintain the temperature. This saves energy by operating at lower speeds and preventing the need for repeated starts and stops, which require more electricity and add wear and tear to the system.

Ductless Systems

This type of unit is very popular overseas where many buildings do not have duct system. Some times called Mini-Splits, ductless air conditioning systems provide another option for homes. Unlike forced-air systems, a ductless air conditioner uses an outdoor compressor unit to provide refrigerant, electricity and drainage into indoor systems mounted on the top of walls of the rooms to be cooled. Since cold air doesn’t get lost by moving through a traditional duct system, this method reduces energy usage by as much as 30 percent. They are becoming popular in the US where homes need to be cooled but no prior existing duct system exists. The air handler is normally mounted on the wall and the condenser is on the outside of the home. With today’s Mini-split systems you can have various air handlers through out the home with one condenser.

Pleated (media) air filters

These types of air filters are more efficient than the standard fiber filter; the media filter is more expensive than a common furnace filter. The throw-away filters that are supplied with the HVAC systems are used to keep the blower/motor clean and will remove particles that are 20 to 30 microns in size only. These are the furnace filters you normally purchase from the hardware store or discount stores. They usually have cardboard frames, which are an inexpensive media but really designed to remove the larger particles and keep the HVAC blower/motor clean those are a MERV 5 rating. The MERV 8 pleated filter is tested to have an average efficiency of greater than 70% on particles of 3 microns and above. It is not particularly effective at smaller sized particles.

Air Purifiers

Air Purification systems can be stand-alone items or paired up with Air Filtration units to address all three types of pollutants in the home – Dust Particles, Microbials and Toxic Chemicals


The Minimum Efficiency Reporting Value is the standard comparison of the efficiency of an air filter. The MERV scale ranges from 1 (least efficient) to 16 (most efficient), and measures a filter’s ability to remove particles from 3 to 10 microns in size. Common airborne particles range in size from .001 to 100 microns. A micron is about one twenty-five thousandth of an inch. To get an idea of size, a hair from your head is about 250 microns in diameter. Dust is a pretty general term and is common issue with most home and building owners. From a visual point of view, anything that is seen as a film of white, grayish or dark particles on a lighter surface constitutes DUST or dust mites. It is in reality made up of many types of particles. Lint, dirt, carpet fibers, dust particles carried in from outdoors, dust & dust mites are generated by pets (dog, cat, others,) children, people, cleaning products, etc. Large dust (dust that you can see which is 20 microns in size or larger) is what most people see and because it is so large, it tends to drop to the floor or on furniture very quickly. The finer particles (those dust mites and particles less than 5 microns, and not visible) stay airborne much longer.

R-22 refrigerant

R-22 is a single component HCFC refrigerant. In 2010, the EPA passed a law to stop production of air conditioning systems containing R-22 refrigerant. Currently, the new refrigerant is called 410A. R-22 refrigerant is still available but very expensive ranging anywhere from $85 to $125 a pound.


A way to increase your home comfort and energy efficiency by controlling when and where heating and cooling occurs in a home. Programmable thermostats are used to control operating times of the equipment. Dampers are used to direct airflow to certain parts or “zones” of the home.


Energy Efficiency Ratings (EER) measure the efficiency with which a product uses energy to function. It is calculated by dividing a product’s BTU output by its wattage.


Stands for Cubic Feet per Minute. A measurement of airflow that indicates how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being forced through the system.


A type of “valve” used in duct work that opens or closes to control airflow. Used in zoning to control the amount of warm or cool air entering certain areas of your home.