Post by Mike Lett
If you look into a commercial kitchen you typically see delicious food being prepared by a chef working over the appliances under a nice stainless steel hood. What you can’t see are the thousands of dollars flowing from the owner’s pocket right outside, being exhausted through that same ventilating hood!
ASHRAE has identified commercial kitchen ventilation as the primary energy consumer in a restaurant. There are 2 steps to implementing an energy efficient approach to ventilation design in a restaurant: the first step is a utilizing a high efficient kitchen hood to provide the lowest exhaust flow possible for proper capture of smoke, cooking smells and grease. Spring Air provides the lowest exhaust rates possible on the market – so with Spring Air you can be assured step one in an energy efficient kitchen design is covered.
The second step ASHRAE has identified is “using demand control ventilation to further reduce exhaust airflow when cooking is not taking place under the hood, but when appliances are hot and ready for food preparation”. Spring Air’s TruFlow Energy Management Controller is the industry leader in complete demand control ventilation solutions.
According to the ASHRAE 90.1 standard, if the kitchen hood exhaust airflow exceeds 5000 CFM then a demand control ventilation system is required. The system has to have the ability to reduce the airflow by at least 50% and not all commercial manufacturers are capable of this. Spring Air hoods can provide this reduction in flow, however vendors can only achieve 30% – so if your high volume kitchen installation is to meet ASHRAE standards be sure that you select your equipment manufacturer carefully. Spring Air is a leader in its field, and you can be sure all equipment is designed to meet the latest ASHRAE guidelines.
Another allowable approach as laid out in ASHRAE 90.1 is to use an energy recovery device with a sensible effectiveness of 40% minimum. If you consider the amount of maintenance required to keep a system like this operating at an acceptable level quickly you will see the potential benefit of the ERV is outweighed by the maintenance nightmare. Filter maintenance in the hood and ERV, wash down of the core itself and cleaning of the ductwork could easily increase your maintenance cost four fold or more depending on the load the hood filters are dealing with. When you consider the cost of labor and service, the clear choice is to look to a VFD demand based control ventilation system.
At the heart of the Spring Air’s TruFlow system is a 10″ color touch screen display which provides visual indication to kitchen staff if they are meeting the demand ventilation goals, and provide complete control of the ventilation system for the kitchen as a whole. The concept of the system is simple – the owner can input the energy savings estimated (typically 30% up to 50% increase in efficiency), once these goals have been entered the display shows the chef when the system is operating within the ventilation goal by displaying a target symbol.
Spring Air’s TruFlow is available for both new installation and retrofit applications which is important as Ontario utilities have been offering rebate incentives of up to $7500 for new installations and retrofits for demand control ventilation (speak with your local utility for more information).
O’Dell Associates has designed and overseen the installation and commissioning of multiple Spring Air projects including University of Guelph, Conestoga College and Longo’s as well as many others. O’Dell’s experience with high efficiency kitchen ventilation is extensive – call your local O’Dell office today to see how we can help you design the most energy efficient commercial kitchen demand ventilation system on the market today.