At James River Air Conditioning, we now HVAC terms can sometimes sound like a different language. Whether you’re discussing a new system installation, understanding your repair options, or just curious about how everything works, it helps to be familiar with the lingo.
That’s why we’ve created this HVAC Glossary of Terms — a simple guide designed to help you better understand the heating, cooling, and air quality systems that keep your home comfortable year-round.Â
From AFUE to Zoning, this glossary covers the essential terms our team uses every day.Â
A
AFUE (Annual Fuel Utilization Efficiency)
AFUE measures how efficiently your furnace converts fuel into heating energy. The higher the percentage
Airflow
The movement or distribution of air within the duct system. Proper airflow is essential for even cooling and heating throughout the home.
B
BTU (British Thermal Unit)
A unit of heat. One BTU is the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit. The highest the BTU rating, the greater the heating or cooling capacity of your system.
BTUH (British Thermal Units per Hour)
The measurement of heat energy a system can produce or absorb in one hour.
C
Carbon Monoxide
A colorless, odorless, and toxic gas produced by burning fuel. It’s crucial to ensure your heating systems are properly maintained to avoid leaks.
Central Air Conditioning System
A system that cools air at a central location and distributes it throughout the home using ducts and fans.
D
Damper
A movable plate within ductwork that helps regulate airflow. It’s used in zoning systems to direct air to the areas that need it the most.
E
Energy Star®
An EPA (Environmental Protection Agency) certification that indicates a product meets strict energy efficiency guidelines, helping you save on energy costs.
Evaporator Coil
Part of your air conditioning system, this coil absorbs heat from the air inside your home. It is typically located inside the air handler or attached to your furnace.
H
Heat Pump
An HVAC system that heats and cools by moving heat between your home and the outside air. In the winter, it draws heat from outside and pumps it indoors. In the summer, it reverses the process, removing heat from your home.
HSPF (Heating Seasonal Performance Factor)
A rating that measures the efficiency of a heat pump during heating mode. The higher the number, the more efficient the system.
I
Indoor Coil
The component within your air handler or furnace that absorbs heat from the indoor air, helping to cool or heat the home as needed.
M
MERV Rating
The MERV (Minimum Efficiency Reporting Value) rating of a filter describes the size of the holes in the filter that allow air to pass through. The higher the MERV rating, the smaller the holes in the filter, the higher the efficiency.
O
Outdoor Coil
Part of your air conditioning or heat pump system that either releases or collects heat, depending on whether you’re heating or cooling your home.
Odors/Chemicals
Airborne contaminants in the form of gases that can affect your indoor air quality.
P
Programmable Thermostat
A thermostat that allows you to set different temperatures based on the time of day. This helps reduce energy consumption and maintain comfort.
R
R-410A Refrigerant
R-410A is a high-efficiency, chlorine-free refrigerant commonly used in residential and commercial air conditioning systems. It replaced older refrigerants like R-22 due to it’s ozone-friendly properties. However, R-410A has high Global Warming Potential (GWP) and is currently being phased out in favor of lower-GWP alternatives like R-32 and R454B, in alignment with new environmental regulations.Â
R-32 Refrigerant
R-32 is a next-generation refrigerant used in air conditioning systems. It has a lower Global Warming Potential (GWP) than older refrigerants like R-410A and offers better energy efficiency.Â
R-454B RefrigerantÂ
R-454B is an environmentally friendly refrigerant designed to replace R-410A in residential and commercial HVAC systems. It has a significantly lower GWP and similar performance, making it a key player in the industry’s move towards more sustainable solutions.Â
**Learn More: Curious about why refrigerants like R-410A are being phased out and what it means for your HVAC system? Check our our Changes in Refrigerant page to get the full scoop of the industry’s transition to eco-friendlier options like R-32 and R454B.
S
SEER (Seasonal Energy Efficiency Ratio)
A measure of the cooling efficiency of air conditioners. The higher the SEER rating, the more energy-efficient the unit, meaning lower energy bills and better environmental performance.Â
T
Thermostat
A device that controls the temperature of your home’s HVAC system, allowing you to adjust settings for comfort and energy savings.
V
Variable Speed Motor
A motor that adjust its speed to match the heating or cooling needs of your home, offering enhanced comfort and efficiency.Â
Z
Zoning
A system that divides your home into separate areas or “zones,” each with its own temperature control. This system improves comfort and energy efficiency by directing airflow where it’s needed most.Â
By understanding these key terms, you’ll be better equipped to make informed decisions about your HVAC system. If you need assistance or have any questions, feel free to reach out to the experts at James River Air Conditioning. We’re here to help you stay comfortable, no matter the season!
I know we both don’t want this, so it’s a good idea to check outside of my unit to make sure everything is clean and running smoothly. 
