Passive dynamic insulation systems for cold 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 use of thick conventional insulation to achieve the very low U-values required by the Passive House Standard, which adds to the overall cost of construction and also 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 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 reduces the risk of overheating during extreme summer months. Importantly, VSDI can be used as a 100% passive component, without a fan to drive the air flow.