PROPER VENTILATION :
THE KEY TO SAVING ENERGY AND MONEY
By Thomas Christiansen
Monday, February 16, 2009
Controlling and lowering costs makes good business sense at the best of times. However, in a slowing economy it becomes essential.
The question is: Where and how much?
Determining how much to cut is the more difficult question as you can only cut a certain amount before it impacts your customers’ experience.
Identifying where to find savings seems easier; inventory controls on food and beverages, lighting controls, temperature controls and choices in small wares can all produce cost cuts and savings.
But where are the real savings to be found?
The top three variable expenses for any restaurant are typically food, labour and utilities, with utilities being the only variable expense that can be reduced without having a negative impact on your customers’ experience. Also, the potential savings are substantial.
Utilities are usually comprised of gas, electricity and water. The utility expense encompasses your entire restaurant, so employing strategies such as lighting controls and water use reduction will definitely save you money.
But have you given any thought to what is going on in your kitchen? Your appliances — both gas and electric — are using tremendous amounts of energy.
In most kitchens, the exhaust hood is connected to a single speed fan, which is turned on in the morning and left running all day. While this means nothing when your dining room is full and your kitchen is serving meals as fast as it can, what about the period between services? The air being exhausted must be replaced. This replacement (or makeup) air can be brought back into the restaurant in different ways. In most cases, however, the makeup air is drawn from outside the building and is then heated or cooled. It is this cost of either heating or cooling the makeup air that can have a huge impact on your profits.
But there are solutions.
Kitchen exhaust hood technology has evolved tremendously over the last 20 years. It is now possible to purchase an exhaust hood that dramatically reduces the kitchen exhaust rate. This is fine for new construction but what about your existing restaurant?
Demand control ventilation has been available for commercial kitchen ventilation for more than 20 years. This technology enables exhaust and supply fans to be controlled based on the demand for air. Demand for air within a commercial kitchen is determined by heat measured within the hood. The higher the temperature, the faster the fans will run to ensure proper capture and containment.
In the course of an operating day, there will be fluctuations in temperature between and during service. Demand control systems sense these fluctuations and control fans accordingly. There are significant savings to be found in taking advantage of these fluctuations, especially if you are heating or cooling the air being brought back into your kitchen.
There are several demand control systems on the market today. All of them control fan speeds by measuring temperature. However, no technology can replace good management. This applies to demand control systems as well. As previously mentioned, the higher the temperature, the faster the fans run. Therefore, if the temperature stays high, the fans will continue to run fast. To maximize savings, a commercial kitchen should implement appliance management programs to turn down or shut off appliances when not in use or during off-peak periods. This will dramatically reduce temperatures in the hood, which will allow the demand control system to further reduce fan speeds. Ideally, the demand control system can also serve as a tool by prompting you or your staff to turn down or shut-off appliances when not in use.
Thomas Christiansen is the sales manager at Spring Air Systems Inc., which specializes in commercial kitchen ventilation systems.
