In the RenewAire (formerly Lossnay) energy exchange core, the exhausted stale air and the fresh ventilation air pass through multiple air passages separated by an engineered composite resin partition plate. Sensible heat transfers from the warmer to the cooler air stream. Also, latent energy (water vapor in the gas state) transfers from the wetter to the drier air stream. The fresh incoming air is automatically preheated or precooled depending on the season. This dramatically reduces the energy costs of ventilation.

This unique moisture transfer feature of the RenewAire (formerly Lossnay) energy exchange core eliminates condensate and frosting in most applications. No mechanical or electrical defrost systems are needed, which means higher heat recovery efficiencies, simpler installation and more reliable operation.