Calculate air flow needed to cool warehouse

We have a warehouse that is 25 ft long by 22 ft wide with ceilings 15 ft tall and a peak in the middle of 20 ft. Inside the warehouse we have machinery that produces 60 kW of heat. The ambient temperature outside the building is between 70F and 80F. We need to know how much air flow is needed to keep the inside air approximately the same as the outside air. Cooling will be accomplished with ventilation only (no air conditioning). The building is constructed of corrugated metal and plywood with drywall on the walls and thin insulation beneath a plywood shingled roof. This warehouse is in Washington state where we have many cloudy and rainy days.