Controlling ventilation and space depressurization in restaurants in hot and humid climates.

Testing was performed in 9 restaurants to identify uncontrolled air flows and pressureimbalances, building and duct system airtightness, building air barrier location, pressuredifferentials, building air flow balance, and ventilation rates. All restaurants are depressurizedunder normal operating conditions, ranging from -1.0 to -43 pascals. Space depressurizationis a function of exhaust fan flow rates, missing or undersized make-up air, intermittentoutdoor air caused by the cycling of air handlers, dirty outdoor air and make-up air filters, andbuilding airtightness. Ventilation rates were found to be high, generally exceeding ASHRAE62-1989 minimum recommended levels. Pressure imbalances and excessive ventilation ratesimpact energy use, heating/cooling system sizing, indoor comfort and humidity, buildingmoisture damage, mold growth, com- bustion equipment problems, and indoor air quality.The objectives of good restaurant air flow management (in hot and humid climates) are to: 1)achieve positive pressure in the building under a majority of operating conditions, 2) avoidexcessive ventilation, and 3) maintain air flow from dining area to kitchen, all whileminimizing heatingkooling energy use and achieving acceptable dehumidification (>60% RHmost of the time). Recommendations are presented to achieve these objectives.