HVAC Glossary: Heating, Cooling & Indoor Air Quality Terms Explained

AFUE stands for Annual Fuel Utilization Efficiency.

Measures how efficiently a furnace converts fuel into usable heat over a heating season. A higher AFUE rating indicates greater efficiency and less wasted energy.

Indoor component of an HVAC system that circulates conditioned air through ductwork.

BTU stands for British Thermal Unit.

A unit of energy used to describe heating and cooling capacity. One BTU is the energy required to raise the temperature of one pound of water by approximately 0.56°C.

BTUH stands for British Thermal Units per hour.

Measures heating or cooling output over time. 12,000 BTUH equals one ton of cooling capacity.

Clean Air Delivery Rate (CADR) is the number of cubic feet of clean air that an air-filtration system delivers in a minute.

Measures how effectively an air purifier removes airborne particles from indoor air.

A colourless, odourless gas produced by incomplete combustion. Proper ventilation and detectors are essential.

Indoor component that absorbs heat and humidity from indoor air during cooling.

A heat pump designed to operate efficiently in sub-zero Canadian temperatures while providing heating and cooling.

The outdoor component of an air conditioning or heat pump system that circulates refrigerant.

Network of air channels that distribute heated or cooled air throughout a building.

EER stands for Energy Efficiency Ratio.

Like SEER, the Energy Efficiency Ratio (EER) of a cooling unit is determined by the output cooling divided by the electrical power input. As opposed to SEER which is calculated over a range of outside temperatures, EER is typically determined by a set outside air temperature, a set inside air temperature and a 50% relative humidity. For a comparison point, 11 EER is roughly equivalent to 13 SEER.

ENERGY STAR is a government-backed program helping businesses and individuals reduce energy costs and protect the environment through superior energy efficiency.

ENERGY STAR is a voluntary labelling program developed by the U.S. Department of Energy and the Environmental Protection Agency (EPA) in 1992 to promote awareness of energy-efficient products. Trane has partnered with the EPA to label our high-efficiency systems with the ENERGY STAR label so homeowners can easily identify those higher-efficiency products that can help reduce greenhouse gas emissions and save energy.

Ventilation system that exchanges stale indoor air with fresh outdoor air while retaining energy and humidity control.

System that transfers heat instead of generating it, providing both heating and cooling.

Ventilation system that exchanges indoor and outdoor air while retaining heat energy.

HSPF stands for Heating Seasonal Performance Factor.

Measures heat pump heating efficiency over a season; higher values indicate better efficiency.

Amount of moisture in the air. Balanced indoor humidity improves comfort and reduces mould risk.

Refers to the condition of air inside buildings, including pollutants, humidity, and ventilation.

Minimum Efficiency Reporting Value; measures air filter effectiveness at capturing particles.

One-millionth of a metre; used to measure airborne particles such as dust and pollen.

If you’re concerned about controlling those airborne particulates, it’s good for you to know that Trane CleanEffects™ removes 99.98% of particulates, all particulates, from the air inside your home.

Industry certification for HVAC technicians demonstrating technical knowledge and competence.

Heating system that burns natural gas to produce heat for distribution through ductwork.

Heating system that uses heating oil to generate heat.

Gas found naturally in the atmosphere; ground-level ozone can negatively affect air quality.

There’s more in the air than you can easily see — all of them potential triggers for asthma and allergy attacks.

“Particulates” is a label used for particles that are really, really small. Some particulates, like hair and pollen, are visible to the naked eye. But most are only visible through a microscope: mould spores, skin flakes, bacteria, household dust, pet dander, tobacco smoke, and cooking smoke.

Why care about something so small? Because anyone with allergies or asthma can tell you, even if you don’t see it, you can still suffer from it. Allergens like dust, smoke and bacteria are particulates that are often .3 microns or less. At that size, they can get deep into your lungs, because they aren’t filtered well by your nose and throat.

Trane CleanEffects™ removes 99.98% of all particulates from the air inside your home.

SEER stands for Seasonal Energy Efficiency Ratio.

Measures cooling efficiency of air conditioners and heat pumps; higher values indicate better efficiency.

Device that allows automated and remote control of heating and cooling systems.

HVAC system with separate indoor and outdoor components working together.

Resistance to airflow within ductwork; excessive static pressure reduces system performance.