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HVAC Terms All Homeowners Should Know

Owning a home is a big responsibility and it’s important to get familiar with these basic HVAC terms and abbreviations.


HVAC stands for heating, ventilation and air conditioning. HVAC is the technology that maintains indoor environmental comfort in buildings, both residential and commercial.

Indoor Air Quality

Indoor Air Quality (IAQ) refers to the cleanliness and health of the air in your home. IAQ factors include particulate count (pollen, mold), humidity and volatile organic compounds found in a home’s air – all of which can aggravate allergy and asthma symptoms.

To learn more about IAQ, check out our previous post, The Rundown on Indoor Air Quality.

Ductwork or Ducts

Ductwork or Ducts are hollow pipes used to transfer air from the air handler to the air vents throughout your home. Ductwork is one of the most important components of a home heating and cooling system.


A piece of equipment that adds water vapor to heated air as it moves out of the furnace. This adds necessary moisture to protect your furnishings and reduce static electricity.

For more information about humidifiers and humidity, check out our blog post, Your Home’s Humidity.


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.

For more information about filters, check out our blog post, All About Filters.


SEER stands for seasonal energy efficiency ratio. A SEER rating measures air conditioning cooling efficiency, which is calculated by the cooling output divided by the total electric energy input during a typical cooling season.

The higher the SEER rating, the higher the efficiency. A great comparison is if you think of SEER like miles per gallon (mpg) for your car. The higher the SEER rating, the higher the MPG. SEER ratings range from 13 to 21. A higher SEER rating will mean a higher level of comfort and lower monthly energy costs, but the upfront cost of the unit will be higher.


AFUE stands for the Annual Fuel Utilization Efficiency of heating equipment. Think furnaces, boilers and heating units that burn oil, gas or propane. Indicated as a percentage, your furnace’s AFUE tells you how much energy is being converted to heat. For example, an AFUE of 90 means that 90% of the fuel is being used to warm your home, while the other 10% escapes as exhaust with the combustion gases. The higher the AFUE, the higher the efficiency of your furnace.

If you have any questions about HVAC terms and abbreviations, give us a call at 847.630.9562 and speak to an On the Mark specialist!

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