Inflatable hot tub vs a hard shell hot tub

The main differences at a glance

The table sums up the usual differences. Individual models vary, so check the specifications of any tub you are considering.

Heating and insulation

A 13 A socket in the UK can supply about 3 kW in total, and the pump, blower and controls share it. That is why most inflatable heaters are rated around 2 kW and why some models pause the heater when the bubbles run. Heating 800 litres from 10 to 38 °C needs at least 26 kWh, which is about 12 hours at 2.2 kW before any heat loss. Try your own numbers with the heat-up calculator.

A hard shell tub on a 32 A supply usually has a heater of around 3 kW and can run jets and heater together. More important, its foam insulated cabinet and thick lid keep heat in, so the heater runs for less time between uses. Air walls on an inflatable lose heat faster, especially in wind and cold.

Energy use over a week

Weekly energy depends on how much heat escapes, which depends on insulation, cover, air temperature and how long the lid is off. An inflatable that is kept warm all week in cold weather can use a lot of energy, because its heater has to keep replacing the heat lost through the walls. A well insulated hard shell tub needs less energy to hold the same temperature.

As a simple example, a 2.2 kW heater that runs six hours a day uses 13.2 kWh a day, or about 92 kWh a week. Run times change with the season and the cover, so treat this as a way of working out your own figure, not a prediction. Our running costs article explains the sums.

Base and space

Both kinds need a level, firm base that can take the full weight of water, tub and people. A filled inflatable of 800 litres weighs around a tonne with bathers, while a large hard shell tub can be well over two tonnes. Hard shell tubs usually need a concrete slab or an engineered base, and decking must be checked by someone qualified to judge its load.

An inflatable is more forgiving about where it goes, but it still needs a flat surface clear of sharp stones, and a mat or ground sheet underneath. See base ideas for the options.

Electrics and safety

An inflatable plugs into a 13 A weatherproof outdoor socket protected by an RCD. A 32 A hard shell tub needs its own circuit from the consumer unit, with an isolator near the tub, and in England new outdoor circuits come under building regulations, so the work must be done or signed off by a qualified electrician.

Note:Never run a hot tub from an extension lead unless the manual allows it, and never improvise wiring. Have new sockets and circuits installed by a qualified electrician. Supervise children around any hot tub, and keep the cover locked when not in use.

Lifespan and upkeep

Inflatable tubs commonly last a few seasons with good care, and the pump is often the first part to fail. Packing the tub away in winter, keeping water balanced and cleaning filters all help. Hard shell tubs are built to last many years, with replaceable pumps, heaters and covers, but they need regular servicing and their parts cost more.

Water care is similar for both: a sanitiser, balanced pH and alkalinity, clean filters and a regular drain and refill, following the chemical maker's instructions.

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Frequently asked questions

Is an inflatable hot tub as good as a real one? It gives you warm water and bubbles for far less outlay, but it heats more slowly, loses heat faster and does not last as long.

Can an inflatable tub stay up all year? Some can, if they have freeze protection and a good cover, but energy use rises in winter. Check the manual for the lowest air temperature allowed.

Do hard shell tubs always need 32 A? Most do. Some plug and play models run from 13 A but cannot heat and run all jets at once.

Which uses less energy? A well insulated hard shell tub usually uses less to hold temperature, while an inflatable that is drained between uses may use less overall.