Eastman Chemical received many complaints about the temperature in the kitchen and dining hall. During peak summer months the temperatures where reaching 90° F and during the winter months it was extremely cold. Storer determined the issue was inadequate amounts of outside air provided to the space. All of the exterior doors were bringing in large amounts of untreated outside air. The kitchen had two exhaust fans that were exhausting approximately 7,000 CFM with no makeup air. This created negative pressure, relative to the dining area, and caused conditioned air to be pulled from the dining area into the kitchen.
Storer proposed providing a direct-fire makeup air unit (MAU) capable of providing enough outside air to keep the kitchen slightly negative relative to the dining area. The MAU included a variable frequency drive to modulate the amount of outside air to each one of the exhaust fans. DDC controls with control dampers and pressure sensors were installed to maintain the proper pressure differential between the kitchen and the surrounding areas, varying outside air supply as required to meet the exhaust air demand. Storer also provided a packaged AC unit to serve the comfort cooling and heating load.
This solution corrected the pressure issues in the kitchen and dining room areas, and comfort has been greatly improved for the occupants.