A Timer, a Cover and Foam...
Hot Tubs Have Energy Saving Options
Timers to the Rescue
If you're like many hot tub owners, you really only use the tub (at most) once or twice a day, and generally at pretty routine hours: often in the morning and then again after dinner or just before
Some electric utilities offer “off-peak” rates — times of day when the cost of electricity is lower. If your utility offers this rate, you may want to consider operating the tub heater during those times. Your monthly hot tub operating costs are determined by how often and for how long the heater has to run to maintain the desired temperature. There are several factors that affect this: the location of the tub, age and insulation level of the tub and the kind of fuel used to heat the tub.
If your hot tub is located inside the house, or in an enclosed area outside, the tub will lose less heat to the environment, and therefore cost less to heat. If it's outside, poorly insulated, or not well shielded from the wind, it may cost considerably more to heat.
Today's modern hot tubs are better insulated than their predecessors. Depending on the age of the hot tub, the insulation can range from a thin layer of foam under the tub shell, all the way up to a fully-foamed cabinet. A fully-insulated tub will maintain its temperature longer, with less supplemental heat required to maintain the desired temperature.
The condition of the hot tub's insulated cover will also have an impact on the cost of operation. If the insulated cover is more than five years old, you may want to think about replacing it. Over time, the foam insulation in the cover absorbs water. That's why the cover gets heavier as it ages. Once the cover becomes water logged, it loses a lot of insulation value and doesn't work as well to stop heat loss. Replacing the cover with a new dry cover will lower your monthly operating costs.
If your tub is located outside, and in a particularly windy spot, consider adding a wind/privacy screen. Not only will the screen reduce the heat loss from the tub caused by exposure to the wind, but it may also increase your comfort while getting into and out of the tub.
More information on reducing energy use in hot tubs, Hot Tub and Pool Conservation Tips, is available from the Washington State University Extension Energy Program.