Resorts and boutique hotels
Sixteen hours of cold plunge a day: what a resort pool and its plant must be built for
A hotel does not use a plunge pool the way a villa does. Guests arrive in waves after a class, a spa slot or a day on the beach, and the water has to be at 4 °C for the last of them as it was for the first. We design the spa garden, the rooftop pool or the wellness deck for that duty, and write the paperwork your technical team will ask for.
An example day in a spa garden, and what it asks of the water
| Hour | Who arrives | What the pool must do |
|---|---|---|
| 06:30 | yoga and breakfast guests | be at 3-5 °C after the overnight run; take 4-6 people in 20 minutes |
| 11:00 | couples with a booked slot | recover between sessions; look clean at eleven as at seven |
| 16:00 | beach-day guests, glass sauna rounds | hold temperature in the hottest, brightest hours |
| 20:30 | after-dinner soak, evening ritual | stay quiet beside the rooms; low light, no glare |
The peak is the hour after the class, not the average hour. That is why a hotel plunge pool starts at 1,100 litres and often goes to 2,000-2,400 litres on two units, with the chillers sized for the queue and not for one early guest. Cold plunge pools explains the heat balance; this page is about duty.
Two units, so that one can be serviced while the other holds
Shared pools run two chillers in parallel. One carries the load, the second is the margin and the backup, and either can be switched off for service without the pool warming up. The duty we design for is up to sixteen hours a day at 3-5 °C within ±0.3 °C. Plant niches get a shaded, louvred position with the exhaust pointing away from rooms, and noise estimates go on the drawing before a unit is ordered.
What your technical team will ask for, and what we supply
| Item | What the team wants | From us, with the free layout |
|---|---|---|
| Drawings | plan, section and plant niche on the architect's grid | 3D layout and plan; shop-level drawings when the contract starts |
| Loads | kW, water and drainage, structural weight | a one-page schedule: heater and chiller loads, litres, floor load |
| Heat rejection and noise | where the hot air goes, how loud it is | an exhaust path on the plan and a noise estimate |
| Water routine | who tests, how often, what is logged | a written routine your housekeeping team can run |
| Warranty and service | who answers, and how fast | two years, plus a service year with assisted visits |
Hygiene: a routine, and a question for the right office
A hotel plunge pool gets filtration, UV or ozone and a sanitiser, a test routine with a log sheet, and a drain-and-refill schedule that follows the traffic. Which water standard applies to a hotel's plunge pool is a question for your provincial public-health office; we do not state a rule, and we put the answer into the specification once you have it. A sauna in the same garden adds a rinse-before-entering rule and a shower between the cabin and the pool.
Renovating in the quiet months without losing to the weather
Resorts renovate between seasons, and the Thai calendar is not the same on both coasts. Phuket's wettest months are August to October, with September the peak at about 350 mm, while Koh Samui's rain peaks later, with November at about 445 mm and June to September far gentler (Thai Meteorological Department, 1991-2020 normals). So an Andaman-coast resort sequences shells and mosaic around the rain, while a Samui resort can often use the middle of the year. The Phuket and Koh Samui pages go through it.
The market numbers, and what they do not say
- International arrivals reached 32.97 million in 2025 (preliminary), after 35.55 million in 2024 (Ministry of Tourism and Sports).
- By province in 2025: Phuket about 10.7 million foreign visitors (76 percent hotel occupancy), Chon Buri (Pattaya) about 10.7 million, Surat Thani including Koh Samui 4.4 million and Krabi 3.6 million (Ministry of Tourism and Sports provincial statistics, counted per province).
- Wellness tourism spending rose 36.4 percent to US$ 14 billion in 2024, within a US$ 42.7 billion wellness economy that ranks 24th globally (Global Wellness Institute, 2026).
Those figures show a large and busy market; they do not show what a plunge pool adds to your rate or occupancy, and we will not invent such a number. The Global Wellness Summit comes to Phuket on 10-13 November 2026, which is a sign of where the conversation is, not a forecast. Budget the cold side as an amenity and the cabin as an add-on; commercial circuits run THB 870k-2.23M before site works.
How many guests can a plunge pool take per hour?
That depends on its size and chiller. A 1,100 litre pool suits two people at a time with a short turnover; hotels expecting a class-sized queue go to 2,000-2,400 litres on two chillers, and further with a third unit. We size it from your expected guests per hour.
Can we retrofit a rooftop pool?
Sometimes. The roof slab, waterproofing, drainage and the lift route decide. We ask for the structural drawings first and tell you at layout stage if it works.
What does a hotel put on the pool-area sign?
A short notice: sessions are short, never plunge alone, avoid after alcohol, people with heart conditions or pregnancy should ask a doctor first. We supply a draft in English and, in phase two, Thai.
Do you build glass saunas for groups?
Yes: eight to twelve seats, from THB 720k-1.03M to THB 1.08-1.48M, with a rinse zone and a separate door onto the pool walk. See glass saunas.
Other clients
A different client, a different circuit
Villa developers and managers
A repeatable spa module drawn into the villa before the slab, and a routine that fits a morning shift.
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Retreats and yoga studios
A warm and a cold pool between the yoga deck and the spa, with a small glass cabin when the budget allows.
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Condos and residences
A compact glass sauna and small cold pool in 10-15 m², planned around the slab, the lift and the committee.
Look closerYour property
Send the spa-garden plan, the room count and the expected guests per hour; we draw the pool and the plant
Start with a photograph
Send the corner of the garden, the terrace or the plant room you have in mind. We answer with questions first, then a layout and a range.
Open WhatsAppOr build the circuit yourself