Commercial Building Heat Recovery

Offices, retail and mixed-use buildings run high outside-air rates for occupants, and that air is conditioned year-round. Recovery is the single biggest HVAC energy lever in a commercial building — and in many climates it is now code-mandated. This is the general case; sector specifics live in the applications guide.

The DOAS + ERV pattern

Most modern commercial designs separate ventilation (a Dedicated Outdoor Air System) from heating/cooling. The ERV sits on the DOAS, recovering heat and moisture between exhaust and supply so the cooling coil and boiler see a much smaller load. Background: DOAS, ERV guide, ERV vs HRV.

Cooling-dominated buildings

In hot-humid climates the win is mostly dehumidification: an ERV pre-dries incoming air, cutting compressor work and mould risk. This is where an enthalpy core beats a plain HRV — see enthalpy vs sensible.

Code drivers

ASHRAE 90.1 and most energy codes now require energy recovery above a ventilation airflow threshold (typically ~1,400–2,000 m³/h) when the climate justifies it. Specifying recovery is often a pass/fail compliance gate, not a nice-to-have — see ASHRAE 90.1 recovery requirements and certifications.

Payback

Commercial buildings run ventilation 8–12 h/day, 250–320 days/yr. At 70–80% effectiveness that is typically 2–4 year payback, faster where cooling dominates. Model it with the payback tool and load estimator.

Spec checklist

• Ventilation airflow (convert with CFM–m³/h).
• Climate → ERV (humid) or HRV (dry heating).
• Cap ΔP (see fan energy).
• Require certification for the tender.