Heating & Cooling Loads6 / 13
Free Cooling & Heat Recovery
Economisers, heat recovery ventilation, and thermal wheels.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
One of the biggest wins in HVAC efficiency is using the outdoors to do your cooling instead of running the chiller. In the UK, this is possible for much of the year.
In this lesson
- 01Outdoor air economizer (free cooling)
- 02When economizer works
- 03Enthalpy recovery (heat recovery ventilation)
- 04Hybrid systems
- 05Practical implementation
- 06Sources and further reading