Direct Vent Equipment Description Guide describing categories of direct-vent combustion space- and water-heating equipment and combustion safety testing.
ECM Air Handler Fans Description Guide describing the use of electronically commutated motors (ECMs) in HVAC central air handler fans to reduce power consumption compared to a single-stage fan motor.
Pre-Retrofit Assessment of Existing HVAC Systems Description Information guide describing considerations for before retrofitting HVAC systems, retrofit scope considerations, and HVAC system replacement options.