To ensure good indoor air quality, installing an Energy Recovery or Heat Recovery Ventilator (E/HRV) is often employed as a solution. Yet, E/HRV installations can lead to unbalanced airflow in three key ways.
According to Srikanth Puttagunta, PE, principal mechanical engineer with Steven Winter Associates, writing for The Energy & Environmental Building Alliance (EEBA), identifies duct issues, install errors, and ineffective frost prevention controls as the three drivers causing unbalanced airflow with E/HRV installations, and offers a solution, by way of a new design that relies on builder input.
To deliver the needed fresh air, an E/HRV must be installed in a way that guarantees balanced airflows—where the intake and exhaust airstreams move equal volumes. But the design of these units makes proper installation difficult and, when integrated with the HVAC system (as most are), almost ensures that they fail to work as advertised.