Hot water may be used in your building for 'domestic' purposes such as showers or washing hands in employee restrooms. It may also be used in specialized machines such as restaurant dishwashers or commercial laundry machines. No matter how you use water or how much you use, there are many ways to cut back on unnecessary energy use.
Reduce heat loss
Install or repair insulation on the hot water storage tank and distribution pipes. If you have an uninsulated or poorly insulated hot water storage tank or uninsulated distribution pipes, adding an insulating jacket or 'wrap' to the tank and installing tubular insulation on the pipes will reduce 'stand-by' heat losses. If the tank is hot or warm to the touch, it needs insulation. Insulating your water tank and piping can reduce your energy consumption by about 4-9%. When insulating, be careful to leave openings for areas on your water heater that need to be accessed. Also, check with the tank manufacturer to make sure insulating your tank is not prohibited.
Reduce the temperature
Often the water heater control is set quite high in order to overcome heat losses from the tank and distribution pipes. A 10-degree reduction in water temperature can result in about a 3-5% reduction in energy usage. With proper insulation of the storage tank and distribution pipes, you should be able to reduce the temperature control setting.
| Hot Water Temperatures |
| Hand Washing | 105 degrees F |
| Showers | 105 degrees F |
| Laundry* | 160 degrees F |
| Dishwasher Rinse** | 180 degrees F |
| *Check code requirements. Even lower temperatures may be practical with some soaps and detergents. |
| **Most dishwashers need water to enter at 140 degrees F to boost it to 180 degrees F |
| Source: 'How to Reduce Your Energy Costs', Advantage Publications and Insights, Boston, MA 1996 |
Use less water
Faucet aerators, which 'spread' the water can reduce the amount of water flow to the tap by up to 50%. Installing occupancy sensing controls and automatic shut-off valves are other efficient ways to control water loss.
Maintenance
It always pays to make inexpensive repairs on leaky hot water faucets, showerheads, and pipe joints. And delaying a repair is not a good idea, since most leaks gradually get worse. Many repairs, such as replacing a sink faucet washer, you can do yourself quickly and easily, and at virtually no expense.
Other maintenance tips:
- Test and adjust your fuel-fired heater
A fuel-fired (gas or oil) water heater can waste energy if it is not burning the fuel properly. Have such a heater checked to reveal whether excess heat is being loss. - Turn off just the circulation pump when hot water will not be needed
Consider turning the circulation system off when your space is unoccupied and hot water is not needed. You can install a simple timer to do this. - Clean out sediment
Any tank-type water heater will lose efficiency if sediment accumulates in the bottom and acts as an internal insulator to inhibit transfer of heat from the heating elements to the water. To make sure these deposits don't build up, periodically open the drain valve near the bottom of the tank and draw off water until it runs clear and the sediment has been removed. For large commercial equipment, a technician should do this.
Change to a high efficiency water heater
If you are replacing your water heater, replace with high efficiency units. As with most energy using replacements, the additional cost for a high efficiency model is quickly paid back in energy cost savings.
Consider a heat pump water heater
The most energy efficient water heater is a heat pump water heater (HPWH). It is available either as an integral unit incorporating a storage tank, or as an add-on to your present water heater where the heat pump heats the water and the storage tank stores it.
