HVAC Terms You Should Know – HVAC Glossary
HVAC Terms It Pays to Know When Replacing Your Heating and Cooling System
No matter the season, your top priority as a homeowner is to stay comfortable when you’re within your own four walls. Most of the time, that means being in an environment that is cool in the summer and warm in the winter. But if you’re preparing to replace your air conditioning unit, heat pump, or your entire HVAC system, you’re about to get hit with a lot of industry jargon.
If it all sounds like mumbo-jumbo to you now, you’ll find it useful to familiarize yourself with a few heating system terms to better understand what your HVAC specialist recommends. Here, we’ll take a look at some common and not-so-common HVAC terms, explore what they mean, and give you the knowledge you need to make smart heating and cooling decisions for your home.
HVAC Glossary
Planning for — and paying for — a new HVAC system can be a head-spinning prospect. But when you understand the terminology you’re likely to encounter, it won’t feel quite as much as if a translator is required. Here are some of the top HVAC terms you may soon hear:
AFUE
AFUE is an acronym that stands for “annual fuel utilization efficiency.” It is essentially a measure of how efficient your furnace is when it comes to converting gas into warm air. An 80% rating is the standard, but 90% or higher indicates a more efficient furnace.
Air Handler
Often called the AHU, an air handling unit, or simply “air handler,” is what moves air through a structure. Not every home will have an air handler, but they are common in those with a ductless system or mini-split (see below).
Air Filter
An HVAC air filter keeps pollutants, contaminants, and particulate matter from entering your home and circulating through your air vents. You should be replacing your air filter every one to three months, and it is the most critical element of DIY HVAC maintenance, which can lengthen the lifespan of your heating and cooling system.
ASHRAE
ASHRAE is the official name of the American Society of Heating, Refrigerating, and Air Conditioning Engineers. It is a professional organization that advances the HVAC industry and promotes sustainable business practices.
Blower
The blower is what moves cooled or warmed air throughout your home. It is often housed within your furnace or air conditioner, but if you have an air handler, you’ll likely find it there.
BTU
A BTU is a unit of measure that stands for “British Thermal Unit.” It measures how much energy it would take to raise the temperature of a pound of water by one degree Fahrenheit.
It may also be measured by time, which would be a BTUH or “British Thermal Units per Hour.” HVAC units with a higher BTU rating will be more powerful, but may be too much for smaller spaces. It’s important to match the appropriate BTU level to the size of your home.
Carbon Monoxide
Carbon monoxide is a poison gas with no odor or color, which is produced when fuels like natural gas or oil are insufficiently burned. Carbon monoxide is harmful when inhaled, and if it goes unchecked, can be deadly. It’s important to monitor your HVAC equipment for potential leaks, and be sure to install and test carbon monoxide detectors throughout your home.
Central Air Conditioning
Central air conditioning is a cooling system that delivers cooled air throughout your entire home through your ductwork. Most central AC units include an indoor unit, an outdoor unit, a thermostat, and the ductwork to push the air where it needs to go.
CFM
CFM stands for “cubic feet per minute.” It measures how much air is moved through your HVAC system every minute. A higher CFM indicates a stronger fan or blower, and is better for larger spaces.
Compressor
The compressor in your HVAC system is what enables the refrigerant to move through your units. It acts like a pump and helps your system absorb heat to create warm air or transfer heat to cool the air.
Condenser Coil
Condenser coils are found in air conditioning units and heat pumps, and they are what expel heat from the outdoor unit.
Cooling Capacity
This indicates how well your air conditioning system can remove hot air from your home. It is typically measured in BTUs or BTUHs. It is important to match your HVAC’s cooling output to the size of your home to ensure efficient operation.
Damper
Dampers are used in your home’s ductwork to direct or control the airflow throughout your living spaces. Most HVAC systems use dampers, though some are controlled manually while others adjust automatically. In a zoned HVAC system, dampers are used to direct airflow only to specific areas of the home.
Dehumidifier
A dehumidifier works to remove excess moisture from the air in your home. It can be a standalone piece of equipment, or it can be integrated into your HVAC system. It can be very helpful in humid climates that are prone to water damage, mold, and mildew.
Ductwork
Duct systems include metal or fiberglass passages that carry cooled or heated air through your home. It is important to keep your ductwork clear and clean, as it can collect debris and dirt, which can restrict airflow and make your HVAC less efficient.
Energy Star
Energy Star-rated appliances and equipment are certified by the Environmental Protection Agency (EPA) of the U.S. government. HVAC systems that display an Energy Star label have met exacting standards and are more efficient and cost-effective than those that aren’t Energy Star-rated.
Evaporator Coil
The evaporator coil is one of two coils in your home’s air conditioning unit. It is typically found in the indoor unit, where it cools the air coming in as the refrigerant evaporates inside.
Expansion Valve
This is the mechanism that controls the flow of refrigerant inside your HVAC system. It reduces the pressure of the liquid refrigerant to decrease wear and tear on your air conditioning system, while allowing for more efficient cooling.
Gas Furnace
A gas furnace is one of the most common heating systems in residential homes. It uses combustion and heat transfer to distribute warm air efficiently throughout your home. Any exhaust from the burning of natural gas is ventilated out of the residence.
Heat Exchanger
Heat exchangers are found in both furnaces and air conditioning units. They are what transfers heat to warm or cool the air before it’s distributed throughout the home. In furnaces, the heat exchanger keeps combustion gases out of the air. In air conditioners, it is the same as the evaporator coil.
Heat Pump
Heat pumps are HVAC systems that both heat and cool the air, eliminating the need for both a furnace and an air conditioning unit. Heat pumps simply transfer heat from one location to another, whether it’s drawing in heat from the outside air in winter, or removing heat from the inside and pushing it out in the summer.
Heat Transfer
This refers to the way heat moves from one location to another. Heat transfer happens via a heat exchanger, which moves the warm air around in order to reach the desired temperature inside your home.
Heating Capacity
Similar to cooling capacity, heating capacity refers to the ability of your HVAC system to keep your home comfortably warm when the temperature outside is cold. Just like cooling capacity, you need to be sure your unit’s heating capacity delivers the right amount of heat for the size of your home.
HRV
An HRV is a heat recovery ventilator, which allows pre-warmed fresh air to enter your home as the stale air moves out. It is ideal for receiving fresher air during the colder months when opening windows is not ideal.
HSPF
Heating seasonal performance factor — HSPF — is a rating that demonstrates how efficiently your heat pump system operates during the cooler seasons. It uses BTUs to measure your HVAC’s operational efficiency.
Humidifier
A humidifier can be freestanding or can be a part of your HVAC system. It works to control humidity levels and add moisture back into the air inside your home by pushing water vapor through your ducts, and is ideal for colder and drier climates.
Indoor Air Quality
Indoor air quality, or IAQ, indicates how clean the air in your home is. It can suffer if a home is too well-insulated or if the outdoor air coming in contains pollutants or contaminants. If this is the case, you might need an addition to your current ventilation, or you may have a heating system leak.
Infiltration
This refers to cold outside air entering your home due to poorly insulated spaces and openings. Reducing infiltration reduces cost.
Load Calculation
Load calculation is how HVAC professionals determine what size and type of HVAC system will be the best to fit the size of a particular space. In the case of most residences, your HVAC technician will recommend a system with heating or cooling capacity that matches your needs and the size of your home.
Mini-Split
A mini-split is a heat pump or air conditioning system that is ductless. It directs heating and/or cooling only to specific areas of the home via air handlers that are often comprise numerous indoor units, all connected to one outdoor unit.
Plenum
A plenum is a chamber where air collects to be distributed or gathered. It is often found in commercial HVAC systems, but can be installed in homes as well. It is usually in the ceiling or below the floor.
Refrigerant
Refrigerant is a liquid used in HVAC systems that goes from liquid to gas and back to liquid as it moves through the system, absorbing and transferring heat. It is used for both heating and cooling, and maintaining the right amount of refrigerant is a critical piece of HVAC maintenance.
SEER
A seasonal energy efficiency ratio (SEER) rating is a mark of how efficiently your heat pump or air conditioner operates during its peak season to cool your home. Understanding SEER ratings can help you choose a cooling system that will save you money in energy costs over time.
Split System
A split system is a cooling method that focuses on a single zone of the home. It consists of an outdoor unit connected to an indoor unit by a refrigerant line. Split systems do not require ductwork and provide greater flexibility and efficiency, especially if you have only a few specific areas of your home you wish to cool.
Thermostat
Your thermostat senses the ambient temperature in your home and uses that to start and stop the heating and cooling system. Your furnace or air conditioner will kick on when the thermostat detects the temperature is too far above or below the desired setting, and will then kick off automatically once that preferred temperature is reached.
Variable Speed
Many HVAC systems operate at a fixed speed, but variable speed units can adjust the compressor and blower to match the specific needs of your home. Variable speed HVAC systems are typically more energy-efficient and keep temperatures more consistent.
At Airtron, We Speak Your Language
You won’t get a lot of confusing industry-speak or jargon from us. No matter what your level of HVAC knowledge, we talk to you in clear, easy-to-understand terms. Knowing a few critical system terms can help you identify areas where your HVAC unit may be underperforming and make it easier to work with your HVAC specialist to ensure optimum performance and savings.
Ready to put your new HVAC knowledge to work? Contact us today!
