Glossary of Green Terms

Air Sealing

Restricts the passage of air through the walls, floor, or ceiling

Air Source Heat Pump

A system which transfers heat from outside to inside a building or from inside to outside a building

Annual Fuel Utilization Efficiency

Thermal efficiency measure of combustion equipment like furnaces, boilers, and water heaters

Duct Sealing

A duct system is used to distribute conditioned air throughout a house. A portion of the air moving through the duct system is lost due to leaks, holes, and/or poorly connected ducts.

Energy Efficiency Ratio (EER)

Ratio of the cooling capacity to the power input


Heating, Ventilating, and Air Conditioning


An insulating material’s resistance to conductive heat flow is measured in terms of its thermal resistance

The R-Value depends on the type of insulation

Seasonal Energy Efficiency Ratio (SEER)

The SEER rating of a unit is the cooling output during the typical cooling-season divided by the total electric energy input during the same period