Energy Implications of Domestic Ventilation Strategy.

Mechanical ventilation with heat recovery (MVHR) and passive stack ventilation (PSV) systems are both proposed as methods of ensuring satisfactory ventilation rates in UK housing. MVHR provides controlled ventilation in all rooms together with heat recovery, while the cheaper PSV system offers lower running costs, but without heat recovery and without a controlled air supply to all rooms. The relative energy consumption of the two systems depends on a number of factors that are difficult to predict. To provide a direct comparison, a test house at EA Technology was fitted with both MVHR and PSV systems. In a pilot study, the systems were operated alternately during the winter of 1993, with controlled internal air temperature and humidity. Both systems provided satisfactory humidity control; the use of humidity sensitive extract with PSV was found to be effective. Overall energy consumption of the PSV system was similar to MVHR.