Alternative Methods for Preheating Outdoor Ventilation Air

In the pursuit of energy efficiency one has developed a complex technology of earth-air heat exchangers (EAHX). In this process, one discovered some drawbacks such as possible entry of radon gas or high humidity in the shoulder seasons. Elsewhere, we highlighted that when the outdoor temperature changes frequently, one needs using two different air intake sources with an automatic selection of the one more appropriate for the actual weather …