Testing of heating and ventilation equipment with the duct test rig.

Canadian research into residential ventilation and combustion venting revealed that the installed performance of exhaust equipment, ducting passages, and site-built chimneys was largely unknown. It became necessary to establish actual characteristics in order to be better able to predict the safety and effectiveness of various ventilation measures. For this reason, Canada Mortgage and Housing Corporation (CMHC), the federal agency responsible for housing policy, had a research device designed and fabricated. The duct test rig (DTR) can be used for taking a wide variety of field measurements. It uses the principal of a zero-pressure difference across the duct opening to negate the effects of the measurement device. There is an internal fan capable of creating flows in a measurable range of 2-390 L/s, and both heat-generating and temperature-sensing attachments to assess duct thermal performance, The fan can be used to generate the pressure-vs-flow characteristics of passive devices, or to aid in fan system flow measurement. Contractors across Canada used the DTR to test 205 houses in the winter of 1988-1989. Preliminary analysis is available on the installed flows of exhaust equipment. Data analysis is ongoing on the areas such as the following: chimney performance, chimney and duct leakage areas, and the comparison of installed exhaust and intake flows.