This paper presents a new technology for capture and containment testing in commercial kitchen ventilation research. It is called large-scale focusing schlieren system and offers a nonintrusive approach to effluent flow observation. Schlieren systems can be added to conventional kitchen ventilation research laboratories or other hood testing facilities and allow continuous observation of a large area around a hood-appliance setup.
This paper presents results of applying the capture and containment test procedures in ASTM Fl 704-96, Standard Test Method for Performance of Commercial Kitchen Ventilation Systems, to determine the threshold capture and containment exhaust flow rates for a number of cooking appliances and two types of kitchen exhaust hoods.
Commercial cooking equipment exhaust systems have a significant impact on the total energy consumption of Foodservice facilities. It is estimated that commercial cooking exhaust ventilation capacity in food-service facilities across the United States totals 3 billion cfm (1 . 4 billion L/s) with an associated annual energy cost approaching $3 billion, based on an average of $1/cfm ($0.47 per L/s) per year. Significant energy and cost savings can be achieved by reducing ventilation rates.
The effects of different kinds of room ventilation were evaluated in an experimental chamber and in kitchens of four residences in Beijing. Carbon monoxide was used as a tracer gas in the chamber, and this together with nitric oxide and nitrogen dioxide concentrations from the gas appliances were measured in the chamber and the kitchens. The ventilation styles evaluated were natural ventilation, an exhaust fan and a kitchen range hood.
The ventilated ceiling is a flexible solution for kitchen ventilation where heat loads are relatively low and aesthetics is a concern. By using a capture jet in the ventilated ceiling, it is possible to improve the total effectiveness of the ventilation system. This means better indoor air quality and thermal comfort. In addition, the energy consumption of a capture jet ceiling is lower than that of a traditional ceiling concept.