HRV vs. ERV: The Complete Engineering Guide to Energy Recovery Ventilation Modern building envelopes are tighter than ever. While high-performance insulation, double-glazed windows, and airtight vapour barriers drastically lower envelope transmission losses, they create an inevitable side effect: trapped air, VOC buildup, high CO2  levels, and uncontrolled moisture. Opening a window throws conditioned energy straight into the street. Uncontrolled infiltration, on the other hand, forces heating and cooling plants to run continuously. The industry standard solution relies on Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs) . These mechanical ventilation devices introduce outdoor air while recovering thermal energy from outgoing exhaust air. Here is the complete engineering breakdown of how they work, the thermodynamic distinctions between them, key terminology, pros and cons, and how to select the right system. 1. Core Terminology You Must Know Before diving i...