A demonstration of low cost DCV technology on five Canadian houses.

Field investigations were undertaken on five houses to determine the potential for improved performance and lower costs through the use of a demand controlled ventilation (DCV) systems. All 5 houses were energy efficient, low toxicity construction, and were chosen to reflect a range of mechanical systems consistent with Canada's new ventilation standard (CSA F326). Three of the test houses were extensively monitored and, after 90 days of conventional operation, were converted to DCV using a wide variety of sensors and controls. A fourth house with a previously installed DCV system was submitted to a series of "activity scenarios" to evaluate the performance of a DCV system based on extractors and inlets that respond to indoor relative humidity. The fifth house was a new house, designed to demonstrate DCV technology, and to validate the insights obtained from the other 4 houses. Commissioning of the new DCV house showed the suitability of using low cost sensors for detecting VOCs, absolute humidity, air flow and activity levels. A low-cost but sophisticated computerized control and monitoring system was used to analyze the ventilation needs and to switch fan motor windings and speeds to create a range of "operating modes" for the ventilation system. A video monitor display with occupant control added a further measure of demand control. The result was a successful demonstration of how currently available and affordable sensors and controls can be used to improve the performance of typical ventilation systems.