HVAC Terminology: What You Should Know

Now that you’re responsible for the upkeep of your heating, ventilation, and air conditioning system, or HVAC, you should be familiar with the lingo and terminology associated with the systems. Knowing the ins and outs of your HVAC system will make communicating to experts about any problems you’re having much easier.

Not only will learning about your HVAC system ease communications between you and experts, but it will build your understanding of the system so that you can perform low-level maintenance by yourself. This will save you time and money over the years as you become less reliant on others to keep your HVAC system running smoothly.

In this article, we’ll go over the basics of HVAC by exploring the most important terminology associated with the systems.

What is AC?

AC is an acronym for air conditioner. This appliance is built into your HVAC system to decrease the temperature of a room and often act as dehumidifiers as well. Central air conditioning units are part of your HVAC system and work to cool and dehumidify your entire house.

There are smaller air conditioning units called room air conditioners or space air conditioners. These are used for only one room, and are typically installed in windows or walls. If you live in a house or full size apartment, you most likely have central air conditioning. If you live in a small apartment or college dorm, you probably have a room air conditioner.

What is heating?

Heating systems use a device like a furnace or coil to heat your home through your HVAC system. When you turn the temperature up on your thermostat, air will pass through the heating mechanism and become warm. This warm air is then circulated about the house.

Central heating is built into the HVAC system of your home, and works to heat the entire home. Additionally, there are space heaters that are smaller units. These units can be plugged into a 120V AC outlet. When activated, they will light up and heat will radiate from the device.

What is ACH?

ACH stands for air changes per hour. This measures how many times an HVAC system completely changes the air supply of a room in one hour. This measure is useful for monitoring the efficiency of your HVAC system. ACH is measured by dividing the amount of cubic feet of air the HVAC unit can provide every hour by the air volume of the room.

You may be interested in reading: How does an HVAC System Work?

What is a coil in AC?

Coils are components that handle heat transfer. They can either be heated or cooled through electricity, cooled vapor, or steam. These are typically mounted inside of an air handling unit or air duct. When you turn on your central heating, the coils are heated and air is blown past them, making the air warm and spreading heat around the house.

The American Society of Heating, Refrigerating, and Air Conditioning Engineers, or ASHRAE recommends that HVAC systems provide 7 to 8 total air changes per hour, and laundry rooms 8 to 9. The ideal ACH rating of a room is based on how many pollutants float around in the air.

What is AFUE?

The Annual Fuel Efficient Ratio, or AFUE, is a measure of how efficient your heating system is. The rating works by comparing the amount of fuel used to heat your home to the amount of energy that is lost through exhaust.

The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) recommends that your heating system’s AFUE rating be at least 80%, meaning that 80% of the fuel consumed is converted to heat. If your heater’s AFUE rating falls below 80%, you should look into investing into a more energy efficient heater.

What is a condenser?

The condenser, or condenser coil, is a refrigeration component that removes heat from the HVAC system. More specifically, these components are heat exchangers that transfer heat outside of your HVAC system through a number of different methods. Your HVAC system’s condenser is usually located outside of the home.

What are air ducts?

Air ducts are channels through which air from your HVAC system makes its way throughout the house, from room to room. The air ducts in your home can be composed of many different materials. Some of the most common air duct compositions include steel, fiberglass, plastic, aluminum, or polyurethane.

Air ducts are often referred to as ductwork, or just ducts.

What is a diffuser?

Air diffusers, or just diffusers, are components that cover vent openings. These tiered fixtures ensure that air escaping from the ducts spreads evenly throughout the room. Clogged or damaged diffusers can cause problems, such as improper air flow, that can lead to more problems with the HVAC unit as a whole.

What is a grille in AC?

Every air duct opening will have a grille over it. A grille is a thin piece of sheet metal with many thin opening slits that resemble a grill. These prevent large objects from getting into the air ducts and blocking airflow, while the openings allow for maximum airflow.

What is a filter and how do they work?

Every HVAC system uses air filters to keep the air in circulation clean. These components are very important for health purposes, as they catch all air pollutants that would otherwise float freely in the air you breathe. There are many different classifications of air filters.

The MERV, or Minimum Efficiency Reporting Values rating system classifies air filters by their effectiveness at catching particles of different sizes. The higher-rated MERV filters can catch essentially anything, even pathogens that are nanometers in size. Low tier MERV filters can catch only the largest airborne pollutants.

The type of MERV filter in your home is most likely between the MERV 8 and 10 ratings. These filters are ideal for households because they can catch all the common household air pollutants while still allowing home-grade HVAC systems to function without interference.

Now, you should be more familiar with the world of HVAC terminology. Hopefully you learned a thing or two about HVAC components, how they work, and gained a better understanding of HVAC as a whole. The next time you communicate with an HVAC expert, you’ll be prepared!