20 HVAC Terms You Should Know

20 HVAC Terms You Should Know


For homeowners, navigating the ins and outs of heating, air conditioning, and air quality can be difficult. This is especially true for first-time homeowners who may not be familiar with any of the terminology used when discussing home climate problems or services.

Not to worry! We have put together a list of 20 common terms used when dealing with HVAC issues around the home. This should make life a little easier when it comes to discussing heating and cooling with the pros, or when you are researching potential equipment repairs or purchases.


Air Cleaner – An air cleaner, or air purifier, is a system that removes dust, dirt, allergens, and other particulate matter from the air in your home. It is possible to purchase stand-alone air cleaners, or those that install as part of your forced-air HVAC system.


Air Handler – This is the component of your heat pump or air conditioner that moves heated or cooled air into the ductwork of your home.


BTU – British Thermal Unit. This is the amount of heat needed to raise a pound of water by 1° F, and is used to measure how much energy is required to heat or cool your home.


Central Air Conditioning – Most of us in Alabama have heard this one before! Central A/C is a system where air is cooled in a central location and then distributed throughout the building using a system of ductwork.


Compressor – In an air conditioner or heat pump, the compressor does what it sounds like it does – it compresses refrigerant in order to help cool warm air. This portion of the air conditioner/heat pump system is located in the outdoor unit. For more information on exactly how a compressor works, check out this post.


Condenser Coil – The condenser coil plays a very important role in how an air conditioner or heat pump operates. This part of the system allows heat from high-pressure refrigerant gas to be released, condensing the gas back into a liquid form. For more information on exactly how a condenser coil works, check out this post.


Condensing Unit – This is the outdoor portion of your air conditioner or heat pump system, which contains the compressor, condenser coil, fan, and other regulatory components. This portion of the system is prone to damage from landscape overgrowth, falling limbs, or projectiles during severe weather.


Damper – There are actually two uses for this term when it comes to heating or cooling. Dampers are paddle-shaped devices used in a home’s ductwork in order to direct airflow to areas of the home. A damper can also reference a device in a fireplace which blocks airflow, preventing air from entering or escaping through an open chimney.


Ductwork – The ductwork of your home allows forced air heating or cooling to deliver the proper temperature air throughout your home. Metal ducts, or tubes, are installed throughout your home, allowing air to travel from the air handler through these specially designed pathways. The air is released through vents.


ENERGY STAR® – This is a designation on home appliances sponsored by the U.S. Environmental Protection Agency (EPA). Products labeled as ENERGY STAR® meet or exceed federal guidelines for energy-efficiency, which can mean savings on energy bills for homeowners if the appliances are used properly.


Evaporator Coil – This is another important component of an air conditioner or heat pump. The evaporator coil absorbs heat from the air, allowing it to either be removed from the home in the case of a cooling system, or transferring it into the home, as is the case with a heat pump. To learn more, see this post.


Heat Pump – A heat pump is a very neat device that can either heat or cool the air of your home by transferring heat from one area to another. We recently did an entire post on heat pumps and how they work – read about it here.


Humidistat – Ever wonder how humid the air in your home actually is? With a humidistat, that information is readily available. It works with your home’s climate system to provide information on humidity levels in your environment. Usually attached to a humidifier, it can maintain preferred humidity levels throughout your home.


HVAC – Super easy…Heating, Ventilation, and Air Conditioning. HVAC companies generally handle all of the climate components of your home.


MERV – Forced air systems always contain a filter that collects particulate matter, so that it doesn’t blow through the ductwork and into your clean home. MERV (Minimum Efficiency Reporting Value) is a rating that tells your about the efficiency of the filter – the higher the rating, the more particulate matter the filter is capable of gathering.


Mini-Split – This type of system operates on the same properties as an air conditioner or heat pump, but without ductwork. Mini-split systems are a great option for smaller spaces, additions, or for homes where the installation of ductwork would be prohibitively expensive.


Refrigerant – Refrigerant is a chemical used in air conditioners and heat pumps in order to provide cooling. It comes in two types – R-22, or Freon, which is being phased out of use due to environmental concerns, and R-410A, which meets new environmental safety standards.


Thermostat – The thermostat is the control center of your heating and cooling system. This is the unit that tells you the current temperature of your home and allows you to set a preferred temperature for your HVAC system to maintain. Programmable thermostats allow you to change the temperature over the course of a day or week for maximum comfort and energy savings.


SEER – The Seasonal Energy Efficiency Ratio measures the energy efficiency of HVAC system components. In theory, the higher the SEER rating, the more energy efficient the equipment is. However, in order for a piece of equipment with a high SEER rating to be energy efficient, it must be used as specified – a higher rating doesn’t automatically mean savings on an energy bill.


Zone – This refers to a specific area of your home. Zoned HVAC systems can provide independently controlled temperatures to “zones” within a home. Zones can be a single room, or an area of the home, such as a separate floor. Zoned systems are great for families that have different heating and cooling needs throughout a single home.