Comparative ventilation systems tests in a mixed climate.

A lab house constructed in Pittsburgh has been used as a site for the comparative evaluation of several ventilation systems. The house was built to relatively high performance standards and is representative of the type of house that would be a candidate for a purposely designed ventilation system. The systems installed and tested were (1) supply fan, (2) exhaust fan, (3) heat recovery ventilator, (4) balanced flow fan, and (5) open pipe to the RA plenum. A number of operational variations were tested with these systems: (1) central HVAC fan off/on/autocycling, (2) internal house doors open/closed, and (3) passive relief vents open/closed. The house was set up for continuous STEM test measurements from November 19, 1997, toJanuaryB, 1998. These tests included (1) overall house UA under each ventilation approach, which yielded a measure of the thermal impact of a system; (2) system operating power; and (3) overall house A CH measurement, yielding an indication of ventilation effectiveness. This paper will present an evaluation of these tests with conclusions concerning the relative performance merit of the five systems in the lab house.