Heating, ventilation, and air conditionings 

Seasonal Energy Efficiency Ratio; higher = more efficient cooling and lower power bill.

A heat load is a analytical data model of your home to determine of exact size of heating and cooling your home requires.

Proper static pressure ensures your system delivers the right amount of airflow for efficient heating, cooling, and comfort.

Annual Fuel Utilization Efficiency; measures how efficiently a furnace converts fuel (gas) to heat, typically expressed as a percentage.

British Thermal Unit; a measure of heating or cooling capacity (1 BTU is the energy needed to raise 1 lb. of water by 1 degree F

Heating Seasonal Performance Factor; measures the efficiency of a heat pump in heating mode.

In HVAC, 1 ton equals 12,000 BTU/h, representing the cooling capacity of 1 ton of ice melting in 24 hours.

The temperature of a liquid below its saturation (condensation) point, typically measured at the condenser outlet.

The temperature of a gas above its saturation (boiling) point, typically measured at the evaporator outlet.

Using dampers and separate thermostats to divide a home into areas with independent temperature control.

Minimum Efficiency Reporting Value; measures filter effectiveness (higher means tighter filtration).

A package unit is an all-in-one unit that both heats and cools. It comes in both heat pump and gas/electric modes.

A split system is a 2 or 3 component and can be all electric (Heat pump) or electric and gas (a/c gas) or dual fuel (Heat pump and gas furnace).

• An inverter HVAC system is a heating and cooling system that can automatically adjust its compressor speed to match the exact heating or cooling needs of the home. 
• Traditional HVAC systems are typically “single-stage,” meaning they are either: 
• Fully ON  
• Fully OFF  
• An inverter system works differently. Instead of constantly turning on and off, it can ramp up or slow down gradually — similar to how a car adjusts speed instead of driving only at full throttle. 

The indoor unit that moves (circulates) conditioned air throughout the house.

The "cold" coil (indoor) that absorbs heat from the home's air.

The pump that moves refrigerant through the system.

A component in a furnace that transfers heat to the air while separating combustion gases.

A device that removes moisture and contaminants from the refrigerant.

Thermostatic Expansion Valve; a device that controls refrigerant flow into the evaporator, providing precise efficiency.

The component in a heat pump that switches from cooling to heating mode.

A safety device that shuts down a furnace if it gets too hot.

Mini splits (also called ductless mini-split systems or ductless heat pumps) are compact, energy-efficient heating and cooling systems that don't require traditional ductwork. They come in single zone or multizone systems. They provide room-by-room (or zone) temperature control, making them popular for homes without ducts, hard to heat or cool rooms (such as bonus rooms over garages), additions, garages, basements, or older buildings. Indoor units consist of wall-mount, ceiling mount, floor mount, and small pancake/slim-duct.

R-22

• If your HVAC system uses R-22 refrigerant, it usually means the system is older and may become more expensive to repair and maintain over time. The U.S. phased out the production and import of new R-22 refrigerant as of January 1, 2020. 

R-410A

• Your HVAC system uses R-410A refrigerant, it generally means you have a newer, more modern air conditioning or heat pump system compared to older R-22 systems. 

R-32 

• If your HVAC system uses R-32 refrigerant, it usually means you have one of the newest generations of high-efficiency HVAC technology. 

R-454B 

• If your HVAC system uses R-454B refrigerant, it usually means you have one of the newest generations of residential HVAC equipment designed to meet updated environmental standards. 

It is designed to: 

• Lower environmental impact  Improve long-term regulatory compliance  
• Support high-efficiency HVAC systems  Reduce Global Warming Potential (GWP)  
• Many manufacturers began transitioning to R-454B around 2025 as new refrigerant regulations took effect. 

Key Performance and Efficiency Differences

• Energy Efficiency: R-32’s thermodynamic properties allow for better heat transfer coefficients and higher volumetric capacity. Under extreme temperature loads, R-32 maintains consistency better than R-454B, leading to potentially lower monthly utility bills.
• System Design: R-32 systems generally require up to 40% less refrigerant charge than older standards, compared to a 10% reduction for R-454B. However, because R-32 operates at a higher discharge temperature and volumetric capacity, systems specifically designed for it utilize compressors and oils incompatible with R-454B.
• Temperature Glide: R-32 is a single-component refrigerant, meaning it has no temperature glide and maintains consistent performance without fractionating during leaks. R-454B is a blend of R-32 and R-1234yf.
• Environmental Impact:
  This is the primary advantage of R-454B. It has a Global Warming Potential (GWP) of 466, which is much lower than R-32’s GWP of 675. Both fall well under the strict regulatory thresholds required by the EPA's AIM Act.