Hospital kitchens consume a large amount of power in order to prepare and reheat meals. The major consumer of energy in the hospital kitchen space is the refrigerator and freezer which account of 20% of the overall energy consumption in the kitchen. This is closely followed by the dish washers which account for 20% of energy consumption. Ensuring that the two functions of refrigeration and dish washing are done efficiently help to reduce the amount of energy consumed.
Hospital refrigeration can be improved by locating the freezer and refrigerator in a place that is moderately cool. Locating these appliances near existing heat sources will be detrimental to the working of these appliances. Energy loss can be minimized by reducing the number of times the refrigerator or freezer is opened and the amount of time it remains open. Using a thermometer check the cooling of the freezer. The warmer the temperature inside the freezer the less energy the freezer will have to consume. A careful analysis using the thermometer will allow a person to set an energy efficient setting that takes into consideration ambient temperature and cooling needs. The refrigerator and cooling rooms should be cleaned and serviced at a regular basis. This includes cooling of the condenser coils to the actual insides of the refrigerator. This will help improve efficiency by negating the insulating effect of dust and prevent any microorganism growth from occurring.
Using dishwashers that have an integrated heat pump can help in saving energy. The St Norbertus Hospital in Duffel Belgium has used an electrically driven air to water heat pump to heat the water in the dishwasher’s storage tank. This is supplemented with an electrical resistance water heater that heats water for rinsing purposes. The heat pump generates cool air which can be further utilized for cooling purposes. At the same time, inside the evaporator the heat pump recovers waste heat from not only the environment but also excess heat generated from drying of dishes. A super heat exchanger can be used to preheat the water up to 70C. Additional heat can be supplemented using the electrical resistance heater.
Lowering the amount of rinse water that is consumed will help to save on energy consumption by dishwashers substantially. Technological improvements that can supplement and increase the efficiencies of commercial dish washers include the use of insulation for the wash tank, wash compartment insulation, reusing rinse water by using a multi stage system that utilizes the reused washer to pre rinse dishes. Other additions that can improve performance include built in booster heaters, heat exchangers, advanced rinse nozzles and infrared burners. With a lifespan of 20 to 25 years the savings incurred by an efficient dish washer will pay back in the long run.
Today there are various types of dishwashers available including under counter, stationary rack door type, rack conveyor machines and very large flight type (continuous conveyor) machines. Dishwashers may use hot water to wash at high temperatures or chemical treatments to use cold water to wash properly. Using Energy Star compliant dishwashers will help in conserving energy. An Energy Star compliant dishwasher is 41% more efficient than a dishwasher that complies with US Federal energy efficiency standards.