Boosting Restaurant Profits With Energy Efficiency
Sanitation and Water Use: Dishwashers
From an operational standpoint, dishwashers are one of the most expensive pieces of equipment in your kitchen. Every rack of dishes you wash can include as many as eleven separate cost items within the three main categories of water, water heating and chemicals. Smart purchasing, operations, and maintenance can save you thousands of dollars in the dishroom.
Don't waste the space! You'll pay the same amount to run a half loaded dish rack as a fully load one, so make sure you only run fully loaded dish racks through the dish machine. Cutting wash cycles could save you hundreds of dollars annually.
Turn it off. High-temp dishwashers typically feature internal tank heaters. If you've got one of these dishwashers and you're not turning it off at night, you're wasting energy by heating water that you don't need. The same holds true for booster heaters and dishwasher exhaust hoods: turn them off at night to save.
Check rinse pressure. Pay attention to your dishwasher's pressure gauge-if it's showing pressure above 25 psi, there's a good chance you're using much more water than is necessary. Most dishwashers require only around 20 psi.
Check water temperature. Follow manufacturer specifications for tank temperature and rinse temperature.
Operate conveyors in auto mode. If you have a conveyor-style dishwasher, make sure you're using it in auto mode, which saves electricity by running the conveyor motor only when needed.
Add or maintain wash curtains. Wash curtains-the plastic strips that hang on both sides of conveyor dishwashers-improve washing efficiency by trapping heat. Replace curtains when the old ones begin to deteriorate.
Design your new dishwashing system with both energy and water efficiency in mind. If you're in the market for a new dishwashing system, it'll pay to look into energy-efficient gas booster heaters. Compared to a standard electric booster heater, a gas booster heater could trim energy costs significantly due to the relative lower cost of natural gas as a fuel (though keep in mind that a gas booster heater could have a higher first cost and installation cost than the electric unit). Also, look for dishwashing systems that use one gallon or less of water per rack washed-typically, the less water required per rack, the less you'll pay in energy costs.
Consider heat recovery. Refrigerant heat-recovery systems use waste heat from the walk-in refrigerators and freezers to preheat water that can be used in the kitchen. These systems are relatively simple and have reasonable payback periods when installed in kitchens with moderate to high hot-water needs.