The paper presents the results of a simulation study performed by means of the COMIS multizone infiltration and ventilation model. The simulations were carried out for a two-storey single-family passive-stack-ventilated house in a cold climate (Stockholm, Sweden). Main conclusions of the study include the following: it is possible - during at least 75 % of the heating season - to achieve a ventilation rate in the whole house of at least 0.5 ach or approx. 30 l/s only if the house has a leakage rate above approx.

Three ventilation systems were installed in the EA Technology Ventilation Test House: passive stack ventilation (PSV), mechanical ventilation with heat recovery (MVHR) and extract fans. Humidifiers were used to simulate occupancy and the performance of the systems monitored over the winter of 1993/94. The aim was to assess the effectiveness of different ventilation systems in controlling indoor humidity at a level that will inhibit the growth of house dust mites.

Elevated temperatures in urban 'heat islands' increase cooling energy use and accelerate the formation of urban smog. Urban shade _trees and light-colored surfaces can offset or reverse the heat island and conceive energy. Implementation of heat island mitigation measures is now a prominent part of President Clinton's Climate Change Action Plan to control the emissions of greenhouse gases, necessitating a better understanding of the quantitative benefits of these control measures.