An inflatable ice bath to try the cold before you build the pool

Why begin with a tub you can fold

A built-in plunge pool is a commitment: a slab, a plant niche, a chiller, weeks of work. An inflatable tub is a season. It tells you whether the cold session survives the novelty, whether the balcony is the right place, whether one person or the whole family turns up at seven in the morning. A fighter at a camp near Rawai, a couple in a Thonglor condo, a yoga studio in Chiang Mai that wants one tub for its retreat weeks: all three are better served by this than by a pool they are not sure about. When the answer is yes, the cold plunge pool or a teak cold tub follows, and the tub goes to a friend or into the car for the next trip.

Bagged ice or a chiller: the arithmetic for Thai tap water

Tap water in Thailand arrives at about 28⁠-⁠30 °C. Bringing 300 litres from 29 °C down to 10 °C with ice alone takes roughly 63 kg, because melting ice absorbs about 334 kJ per kilo and the melt water still has to be warmed to the bath temperature: a car boot of bags from the corner shop every day, and the water is back in the twenties by the afternoon. A 1 HP chiller removes the 7.6 kWh that take the working fill from 29 °C to 4 °C in an overnight run, then holds 3⁠-⁠5 °C for as long as the lid is used. Ice is the right way to try the cold for a week; the chiller is the right way to keep it for a year.

What arrives, and what we do on the day

• The tub. Drop-stitch PVC walls that stand rigid when inflated, a soft floor, a drain valve low on the side.
• The lid. Insulated and fitted; without it, Thai air warms the water several degrees an hour and leaves and insects move in.
• The pump. A small electric pump inflates the walls in minutes; a hand pump is in the bag for the day the power is out.
• The chiller set, if chosen. Our 1 HP unit, a filter, two insulated hoses and the fittings; we place the unit where its warm exhaust goes outside, not back into its own intake.
• Set-up. About an hour from the box to a full tub, with a walk-through of the drain, the valve and the routine.

The folding tub against the three things it is not

The trade is plain: the inflatable costs a fraction, moves with you and survives a season of hard use, but it has no seat, its walls insulate less than a shell, and the sun on a Phuket terrace is unkind to PVC. The free-standing ice bath tub is the next step up once the habit has stuck and the spot is settled.

Balcony, camp or studio: three Thai places it goes

• A condo balcony. A full tub weighs 300-450 kg on a small footprint, so the slab and its drain are the first questions; the chiller is the second, because the juristic person may want a word about noise. The condo field note lists what to ask.
• A Muay Thai camp or a small gym. One tub beside the ring for the fighters after the afternoon session, a rinse-first rule on the wall and a water change every two days without a chiller. When the queue grows, the club page explains why the pool takes over.
• A yoga studio or a retreat week. The tub stands for the week, then folds; the chiller waits in a cupboard for the next one. The retreat page shows the built version.

Keeping the water clear in a tub with no filter of its own

Without a chiller the tub has no circulation, so the rules are short: rinse before you step in, lid on after, and change the water every two or three days in Thai heat, more often if several people use it. With the chiller the water passes a filter whenever the unit runs and lasts far longer; wipe the walls at the waterline when you change it, and keep the tub out of direct sun so that the PVC and the cold both last.

When the tub has done its job

The chiller is the part that lasts. The same 1 HP unit that held the inflatable at 4 °C pairs with the 250 litre compact composite tub later, and a 2 or 4 HP unit from the chiller page takes over when the pool is built. The configurator lists the inflatable tub as a cold-side option with its chiller, and the budget ranges page puts it next to everything it might grow into.