Moisture levels in intensive swine operations (ISOs) are a concern in cold climates, as excess moisture may lead to condensation and bacterial growth inside the rooms. The moisture production (MP) of two grower-finisher rooms were measured and compared to predicted values to determine the validity of moisture production equations currently used for design purposes. The CIGR (1984) equations provided the best average MP values, with an 8% difference, and for all the prediction equations used in this study, diurnal MP patterns were not predicted.

If the current MP is actually higher than predicted in swine barns, the minimum ventilation rate to control the humidity level of the room needs to be higher than the current design criteria. If the minimum ventilation rate increases, the current heater capacity may not be sufficient to compensate for the additional heat loss in cold conditions. The CIGR (1984) equations may be used to predict average MP values for design purposes, but additional work needs to be done to update the MP equations to better reflect the actual MP conditions in swine grower-finisher rooms. This will help to ensure the engineer selects the proper minimum ventilation system design for the ISO.