This paper is based on a three year period of research. In year one, a computer-based data gathering system was installed in each of two 100-sow barns at the Prairie Swine Centre. The ventilation systems in the six rooms in each barn were nodified to enable a detailed study of air inlets, air distribution, heat exchangers, exhaust fans, and fan-heater controllers. In year two, major modifications were made to the continuous slot inlets in the farrowing and breeding/gestation barns. Year three of the project was intended as a clean-up year in which data analysis was to be completed.
What is minimum ventilation and what is the minimum ventilation rate for various swine barns? Tests with variable speed fans and fan controllers is included in this paper. Air inlets should be closed tight enough to maintain negative static pressure across the fan of 0.05 to 0.10 inches. Backdraft devices are needed on intermittenly operating fans to prevent the fan from acting as an air intake when the fan is not running. Energy efficiency is compromised when fans must overcome shutters that close by gravity. Dirty shutters or backdraft shutters will not affect the performance of fans operating at full speed.