Many utilities provide water heater “blankets” at no cost. Others offer rebates to businesses and individuals who purchase high-efficiency hot-water heaters that have extra insulation built into the unit. If the heater is in the conditioned space, heat emanating from the unit adds to the load on the air-conditioning equipment. If the unit is located outside — and is poorly insulated — a lot of heat will be lost in the winter. In either case, it’s essential to maximize insulation.
The thermal energy lost from a water heater is called “standby loss.” The water heater in my house is in a mechanical/storage room on the lower level. In the winter, the heat lost rises to the upper floor. In this case, there are zero standby losses.
In my last house, the water heater was in a closet on the outside wall, accessed via an outside door. Since doors don’t have much insulation value, the water heater was essentially situated in the ambient temperature. In the winter, this maxed out the possible standby losses from the unit. Likewise in houses where the water heater is in the garage or some other unconditioned space.
__________
Excerpted from Going Green, available as an eBook at this list of eBook retailers online.
