Before Start-up

Verify airflow balance, filter installation, and that controls (bypass, frost, alarms) are configured.

Measure On Site

• Supply and exhaust airflow
• Inlet and outlet temperatures on both streams
• Pressure drop across the core

Calculate Effectiveness

Use the measured temperatures to compute actual effectiveness and compare it with the rated curve at the same conditions.

Document

Keep the commissioning sheet with the O&M manual. It is the baseline for future troubleshooting and verifies the savings claim.

Plan the Airflows

Recovery works best when supply and exhaust are balanced. Design the duct runs so both sides carry similar flow.

Position the Unit

• Accessible for filter changes and service
• Level, with rigid support to avoid vibration
• Close enough to avoid long, lossy ducts

Condensate and Drainage

Sensible cores condense in cooling mode. Provide a drain or pan with safe routing, and insulate cold ducts to prevent sweating.

Controls

Wire summer bypass and frost protection per the manual so the unit runs efficiently across seasons.

Start With the Test Conditions

A datasheet is only comparable if you know the airflow, temperature difference, and face velocity used. Missing conditions is a red flag.

Key Fields

• Sensible and total effectiveness at stated conditions
• Pressure drop on each side
• Maximum operating temperature and pressure
• Leakage rate between airstreams
• Certification (Eurovent, AHRI)

Watch For

A single best-case effectiveness with no curve, or a pressure drop quoted at a different airflow than the effectiveness. Both hide real-world performance.

Decision Aid

Build a small comparison table of the fields above across shortlisted models before choosing.

Step 1 - Gather Duty

Write down supply and exhaust airflow, indoor and outdoor design temperatures, and the allowable supply-air temperature.

Step 2 - Pick Effectiveness

Choose a target (say 70 percent) and confirm the technology (plate for sensible, membrane for latent).

Step 3 - Estimate Face Area

Effectiveness rises with face area and falls with face velocity. A larger core at lower velocity gives more recovery but costs more space.

Step 4 - Check Pressure Drop

Each core adds static pressure. Confirm the existing fan can deliver the combined airflow at the new total pressure, or upsize the fan.

Step 5 - Verify

Confirm against an EN 308 or AHRI 1060 rating at your actual operating point, not the headline number.