(Photo: Hugh Cairns)

When we are talking temperature, air conditioning is the removal of heat from indoor air for thermal comfort.

In most cases, excess heat is bad for the body because it can lead to health problems. Most air conditioning units filter the air, leading to better quality breathing. In the heat of the summer when temperatures soar, air conditioners can be life savers. Sleeping in excessive heat is difficult and often miserable. Lack of sleep to excess heat can cause a host of health complications too.

Air conditioners work very much the same as your fridge. They use electricity as its power source and they have compressors that pump refrigerant through the system to gather heat and moisture from indoors and remove it from the home. The heat and moisture are removed from the home when warm air from inside the home is blown over the cooled indoor coil. The heat in the air transfers to the coil, thereby "cooling" the air. The heat that has transferred to the coil is then "pumped" to the exterior of the home, while the cooled air is pumped back inside, helping to maintain a comfortable indoor temperature.

Window and wall mounted air conditioners are capable of cooling between 300 and 1800 square feet. Horizontal window units are designed to fit a vertical sliding or hung sash window, while vertical window units are designed to fit horizontal sliding or casement windows. Window-mounted units can also be removed and stored with the change of seasons. The main benefit of wall mounted units is that they can be installed and sealed permanently so less cool air leaks back outside, which will save you energy and money in the short and long run.

(Photo: Hugh Cairns)

The inset thermal image was taken using a thermal imaging camera to verify the cooling capabilities of this air conditioner. The dark blue square represents cool air exiting the unit at 43 F.

Room air conditioners are rated in Btu (British thermal unit) capacity. If the insulation in your home is minimal or the air conditioner sits in a hot, south-facing window, opt for a unit with higher Btu. If possible, avoid installing the cooling unit in a south-facing window that gets lots of sunlight as it reduces the unit's efficiency.

Newer models feature advanced features such as a variable-speed compressors, which adapts its cooling capacity to the desired ambient temperature. Once this temperature is reached, the compressor then goes into energy-saving mode and only uses the minimal energy required to maintain that temperature. Certain air conditioners also come equipped with an air cleaner/ionizer, which provides better air quality. Both adults and children will like the increased feeling of well-being that this creates at home.

As with any other purchase of a major appliance, it’s always best to take your time when shopping to ensure that you get the best value for your money.

For more tips on purchasing wall and window mounted air conditioners click here.

Hugh Cairns welcomes your questions, comments and suggestions. Contact him through www.subject2homeinspections.com or interiorinfrared.com.