Table of Contents
- An AHU conditions outdoor air before it enters a building. The core components are: the supply fan, the exhaust fan, filters, coils (heating/cooling), and - increasingly - a heat recovery core. How these are arranged decides both air quality and energy use.
- Supply and exhaust fans move the air. Their efficiency and the pressure drop across every component set the fan power. A recovery device that adds 100 Pa can quietly raise energy use by 10-20%.
- Filters protect occupants and coils. Rating runs from coarse (ISO Coarse / MERV 8) to fine (ePM1 / MERV 13+). Cleaner air costs more pressure drop, so filter choice and recovery placement must be balanced together.
- The recovery core - plate, rotary, heat pipe, or run-around coil - sits between the two airstreams. In a new build it is designed in; in a retrofit it is added to the exhaust riser (see retrofit guide).
- Recovery must be sized with the AHU, not bolted on. Use our AHU selection calculation to balance effectiveness, pressure drop, and fan energy before ordering.
An AHU conditions outdoor air before it enters a building. The core components are: the supply fan, the exhaust fan, filters, coils (heating/cooling), and - increasingly - a heat recovery core. How these are arranged decides both air quality and energy use.
Supply and exhaust fans move the air. Their efficiency and the pressure drop across every component set the fan power. A recovery device that adds 100 Pa can quietly raise energy use by 10-20%.
Filters protect occupants and coils. Rating runs from coarse (ISO Coarse / MERV 8) to fine (ePM1 / MERV 13+). Cleaner air costs more pressure drop, so filter choice and recovery placement must be balanced together.
The recovery core - plate, rotary, heat pipe, or run-around coil - sits between the two airstreams. In a new build it is designed in; in a retrofit it is added to the exhaust riser (see retrofit guide).
Recovery must be sized with the AHU, not bolted on. Use our AHU selection calculation to balance effectiveness, pressure drop, and fan energy before ordering.