> For the complete documentation index, see [llms.txt](https://docs.betterbuilding.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.betterbuilding.io/user-guide/2d-building/building/hvac/hvac-templates/heat-recovery-ventilation.md).
# Heat Recovery Ventilation
A heat recovery ventilation (HRV) system is designed to improve indoor air quality while minimising energy loss. It typically consists of supply and exhaust fans, a heat exchanger, filters and controls. The system draws in fresh outdoor air and removes stale indoor air simultaneously. The heat exchanger transfers thermal energy between the incoming and outgoing air streams, reducing heating or cooling demands on the building. Filters remove particulates from both air streams, and controls regulate airflow rates and system operation based on occupancy, indoor air quality or time schedules.
It is composed of:
* Air Handling Unit(s)
* Air Terminal(s)
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