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Guides 2026-09-29

Air-to-Air Heat Recovery for Commercial Buildings & AHUs

Air-to-Air Heat Recovery for Commercial Buildings & AHUs

A commercial building's fresh-air handling unit (AHU) brings in outdoor air to meet ventilation codes — and in winter that make-up air must be heated from scratch while an equal volume of warm indoor air is exhausted. An air-to-air heat exchanger in the AHU recovers the heat from the exhaust and pre-warms the incoming air, cutting heating (and summer cooling) cost with no moving heat carrier. This guide covers AHU heat-recovery selection.

Why AHU Recovery Pays

Buildings with high outdoor-air rates (offices, schools, hospitals, labs) lose the most through ventilation. A sensible plate or heat-pipe core recovers 60–90% of the exhaust heat; an enthalpy wheel adds latent recovery for humid climates. The math is in our efficiency reference and the HRV piece heat recovery ventilation (HRV) system.

Plate vs Wheel in an AHU

For most commercial AHUs a fixed plate core is the default: silent, no motor, no cross-leak. Choose an enthalpy wheel when indoor humidity must be balanced (hot-humid climates, pools) — the latent question is in sensible vs latent recovery and the wheel explainer enthalpy wheel heat recovery. Where a wheel is unsuitable (contamination-sensitive exhaust), a plate or heat pipe wins — see where wheels are banned and rotary vs plate.

Sizing the AHU Core

Match the core to the design outdoor-airflow, not peak. Oversizing hurts effectiveness. Our sizing guide walks the calculation, and the pressure-drop reference sizes the fans. A worked winter example: indoor 22°C, outdoor −8°C, 80% effective plate → supply arrives at ~10.8°C instead of −8°C.

What to Specify

Item Recommendation
Core (default) Counter-flow plate
Core (humid climate) Enthalpy wheel / membrane ERV
Effectiveness 70–90% sensible
Frost protection See frost prevention

Related

See our application library and how an air-to-air exchanger works.

Get an AHU Core

We supply plate, heat-pipe, and enthalpy-wheel cores for commercial AHUs, sized to your outdoor-air rate and climate. For a quotation, contact +86 15753355505.

Engineering calculators

Run the numbers for your project: savings, sizing, psychrometrics and duct pressure.

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