Can ‘energy hog’ hot tubs be made greener?

There are measures that can make the hogs a bit less greedy.

One factor is how a hut tub is powered.

Hot tubs usually come with their own electric heaters, so using a green energy source will cut the carbon dioxide footprint.

Those heaters can also be combined with solar water heating, to cut the need for electricity.

However, for those installing hot tubs in their owns homes, that might be an extra level of complexity.

For retail customers, “simplicity is key,” says Karl Rowntree, the technical director for the UK hot tub manufacturer RotoSpa.

Holiday parks are more open to alternative heating systems, including solar and biomass boilers (which can run on wood pellets or even coffee waste) and heat pumps.

A heat pump for a hot tub would be more energy-efficient, external than an electric heater. The buyer’s guide WhatSpa? estimates that a standard electric heater uses more than three times as much power, external during a heating cycle, compared with an air-source heat pump.

Mr Rowntree says that an air-source heat pump can cut energy costs by up to 75%, and can pay for itself within three years.

Other factors include how well the tub is insulated and covered, to reduce heat loss; how large it is, which affects how much water needs to be heated; and the temperature settings.

Mr Rowntree says that energy efficiency features on the control system can also help. He uses a sleep timer on his own tub, which he puts in sleep mode between 11:00 and 07:00.

Although it cools down overnight, it’s still cheaper than leaving it on through the night, he explains.

Of course, there is the option of a wood-fired hot tub. Its environmental impact would partly depend on whether the wood was from a sustainable source, but burning wood is always going to produce carbon dioxide.