Air-to-Air Recovery: ERV & HRV

Every building that ventilates throws warm air outside and pulls cold air in, then spends energy heating the cold air back up to the temperature of the air it just expelled. Air-to-air heat recovery closes that loop: it captures heat from the outgoing exhaust and uses it to pre-warm the incoming fresh air, without the two streams mixing. On mechanically ventilated buildings it is often the single largest heat recovery opportunity, and modern Building Regulations effectively require it on new systems. This lesson covers how it works, the HRV-versus-ERV choice, and what it saves.