5 HVAC Terms You Need to Know to Understand Your System

Like any field, the HVAC industry is full of lingo that could make it difficult for homeowners in Alton, Illinois, to understand their technicians. Get to know these common HVAC terms and you’ll be prepared to make more informed decisions regarding your heating and cooling system.


Don’t be embarrassed if you didn’t know what HVAC stands for until now: Heating, Ventilation, and Air Conditioning. HVAC is a general term that refers to virtually everything related to the air in your home.


AFUE stands for Annual Fuel Utilization Efficiency. AFUE is a system of measurement used to evaluate the efficiency of your furnace. AFUE is measured by dividing the ratio of heat output by heat input. If your furnace has a high AFUE rating, it’s an energy-efficient unit.

Air Handler

The air handler of your air conditioner is the indoor component of your system that houses the circulating fan and evaporator coil.


BTU, also known as British Thermal Unit, measures the heat required to increase or decrease the temperature of one pound of water by one degree Fahrenheit. BTUs are often used to rate heating systems; the higher the BTU rating, the more capable your system will be at efficiently heating your home.


SEER stands for Seasonal Energy Efficiency Ratio and refers to the ratio of output cooling energy to input electrical energy of a cooling system. If your air conditioner has a high SEER rating, your system is energy efficient.

MERV Rating

MERV ratings will be important to you if you need to maintain high indoor air quality. MERV rating, or Minimum Efficiency Reporting Value, determine the efficiency of an air filter. The most efficient air filters have smaller holes, which allow fewer particles to pass freely through the filter. A high MERV rating indicates small holes and an efficient filter.

These are just a few of the common HVAC terms that you may read online or hear from your HVAC technician. To improve the SEER rating of your air handler or the AFUE of your furnace, call Den-Son Inc. Cooling & Heating at 618-207-3847.

Image provided by Shutterstock

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