An Experimental Study on the Effect of Outdoor Temperature and Humidity Conditions on the Performance of a Heat Recovery Ventilator

The purpose of the present paper is to investigate the effect of outdoor weather conditions on the performance of a plate-type heat recovery ventilator. The performance should not be affected in a theoretical point of view. However, the performance varies in real applications, because of air leakage, motor heat generation, and etc. Experiments have been conducted to measure the sensible, latent, and enthalpy efficiencies by varying outdoor temperature and humidity conditions with the indoor conditions fixed at the standard heating or cooling conditions. The coefficient of energy has been introduced to quantify recovered energy in comparison with the electric power consumption. Results indicate that the temperature exchange efficiency under winter conditions shows larger values than in summer conditions due to the heat generation by an internal fan. With the heat gain eliminated, the modified temperature efficiency remains almost constant regardless of outdoor temperature conditions. The enthalpy efficiency can exhibit very large values or negative values in case outdoor conditions are in the vicinity of the indoor enthalpy line. The direction of heat flow, in such a case, can be opposite to that of moisture flow between two air streams. Discussions are included about various interesting features of the psychrometric processes occurring in a heat recovery ventilator for various outdoor temperature and humidity conditions