Most small businesses use hot water even if only for employee hand washing. Restaurants, hotels, and other businesses that use hot water for large purposes such as dishwashing and doing laundry can spend 25 percent or more of their total energy bill on hot water. Fortunately there are many low-cost, easy-to-apply methods for reducing your hot water costs.

Turn off your water heater. Although this may seem obvious, it really is a great idea. Buy a 7-day thermostat (you can get one for about $30) to turn off your electric water heater at night and on weekends and to turn it back on one hour before your business starts up in the morning. If you have a big water heater, you can get even more aggressive and turn it off an hour or two before quitting time. The already-heated water will be sufficient for late-day needs. You’ll save anywhere from $10 to $50 per year with a water heater timer. Along the same lines, consider shutting off a dedicated water heater that is rarely used and turning it on only when it is needed. If you use a circulating pump, be sure that it is shut off when the facility is unoccupied. Again, a timer will help you remember. Circulating pumps increase heat loss through pipes that circulate hot water. A 1/8 horsepower pump that is turned off for 2,000 hours per year will save you $25 in pump energy alone.

Lower the thermostat setting. The hotter the water temperature, the faster you lose energy through the pipes and water heater tank walls. Therefore, lower the thermostat to provide hot water at the lowest acceptable temperature. Some tasks, such as doing laundry or washing dishes, and some businesses, such as health care facilities, require higher water temperatures than others. These temperatures may be set by state and local codes. A small office with an electric water heater that is used only for hand washing purposes would save about $10 per year if the setting is changed from 130 degrees to 120 degrees at no cost. If one task, such as laundry, requires significantly higher temperatures than other tasks, it may be more efficient to reconfigure your piping to include a blending valve. (The hottest water should be piped directly from the heater to the high-temperature task; the water for the remaining tasks should branch off and pass through a blending valve, which mixes in coldwater to reduce the water temperature for the other tasks.) Alternatively, you may wish to install separate heaters for high-temperature and low-temperature tasks or to provide booster heaters for high-temperature tasks. Some machines provide their own booster-heating mechanisms.

Insulate your tank. To reduce heat losses in your hot water system, make sure that your hot water storage tank and the hot water pipes connected to it are insulated. Few hot water tanks are totally uninsulated nowadays.

Move your water heater. If you are remodeling, take the opportunity to relocate your water heater as close as possible to the main point of water consumption. This will reduce heat loss from the pipes.

Buy a new water heater. If you buy a new water heater, be sure to consult the EnergyGuide label on the appliance so that you select an efficient model. Consider using a heat pump water heater, particularly in situations where the simultaneous cooling it would provide would be useful. A relatively new and more efficient technology, heat pump water heaters remove heat from the surrounding air and transfer it to the water. Because these water heaters also cool and dehumidify the surrounding air, they are particularly beneficial in warm, humid areas such as kitchens and laundry rooms. Another excellent alternative is tankless, instantaneous, on-demand water heaters, which are quite popular in Europe. They are growing in popularity here, too, especially in areas where relatively small amounts of hot water are used on occasion. Tankless water heaters eliminate tank losses and are great for office buildings that have only sinks. Tankless water heaters typically supply up to two gallons per minute of hot water, about the same as required for a shower and more than enough for most office sinks. One catch is that they may require heavier wiring, so check with your contractor before making a decision. Or, don’t buy a new water heater. Consider turning your standard water off except for emergencies and using “free” waste heat recovery to meet some of your water heating needs. Waste heat sources include laundry or dishwashing rinse water, steam condensate lines, and refrigeration equipment.

Maintenance
To maximize savings and keep your hot water system operating efficiently, you should perform periodic maintenance procedures. Storage-type water heater tanks should be flushed out about annually to remove sediments that reduce system efficiency. (Flushing involves opening the drain valve at the bottom of the tank and drawing off water until the water runs clear. Follow your manufacturer’s instructions. In areas with high mineral content in the water, you may need to do this more often.) The burners of gas- or oil-fired water heaters should be tested and adjusted annually to make sure that the fuel is being burned as efficiently as possible. In addition, it is good practice to periodically flush your fixtures with very hot water to control bacteria growth.

Source: U.S. EPA, Putting Energy Into Profits, ENERGY STAR® Small Business Guide