A passive-active dynamic insulation system for all climates

Common features of Passive House design are thick walls and air tight construction, to minimise heat loss and infiltration respectively. This is due to the use of thick conventional insulation to achieve the very low U-values required for the Passive House Standard, which adds to the overall cost of construction and also potentially contributes to problems such as interstitial condensation. High performance, exotic insulation materials such as silica aerogels and vacuum insulation products could help to reduce thickness but at a cost that is at present prohibitive. In this paper the author introduces the basic concept and some illustrative simulated performance results of a new Void Space Dynamic Insulation (VSDI) technology that couples low cost conventional insulation materials with efficient ventilation to deliver low loss building envelopes and high indoor air quality in thin wall construction. The advantages of VSDI are that it eliminates the risk of interstitial condensation and the risk of over-heating during extreme summer months. Importantly, VSDI can be used as a 100% passive component, without a fan to drive the air flow.