Gyms, fitness studios and leisure centres put more strain on air conditioning than almost any other kind of room. People are working hard, often in large numbers, for long hours. They breathe heavily and sweat, so the air gets warm and damp at the same time.
This guide is for gym owners, studio operators and facilities managers planning a new installation or replacing an old one.
Why a gym needs its own approach
Three things make gym air conditioning different from ordinary comfort cooling.
- Heat from people. Someone on a rowing machine gives off far more heat than someone sat at a desk. In a busy class the people are often the biggest single heat source in the room, so we size for the room at its busiest hour, not an average.
- Moisture. Breathing and sweating put a lot of water into the air. Air conditioning removes some of it as condensate while it cools, but the system has to be chosen and set up with humidity in mind, or the room feels clammy even at a sensible temperature.
- Long hours. The equipment needs to suit long running hours, and maintenance has to be planned around that use.
The law doesn’t set a maximum temperature for a workplace. HSE says employers must provide a reasonable indoor temperature, and its guidance on what the law says notes the Approved Code of Practice suggests at least 13°C where much of the work involves rigorous physical effort. Heat is treated as a hazard, so if your staff coach classes all day, cooling is part of managing their working conditions as well as keeping members happy.
Fresh air comes first
Most air conditioning indoor units, such as wall-mounted and cassette units, recirculate the room air. They cool it and filter it, but they don’t bring in outside air. In a gym that’s a problem, because a full room needs a steady supply of fresh air to keep carbon dioxide and stale air down.
HSE’s guidance on improving ventilation says systems that recirculate air, including air conditioning, should be designed with fresh air inlets, and that recirculated air should be adequately filtered. HSE also suggests CO2 monitors as a broad guide: it says levels consistently above 1500ppm in an occupied room indicate poor ventilation.
So the right answer for most gyms is two systems working together: mechanical ventilation (ideally with heat recovery, so you aren’t throwing away the heat or cooling you’ve paid for) and air conditioning to handle the temperature. Changing rooms and showers need their own extract. See our ventilation and MVHR page for that side.
Which system suits which space
There isn’t one gym layout, so there isn’t one gym system. What we usually consider:
| Space | Typical choice | Why |
|---|---|---|
| Small studio or PT room | Wall-mounted split | Simple, quick to fit, easy to reach for filter cleaning |
| Open gym floor with a suspended ceiling | Ceiling cassettes | Air thrown in several directions, units out of the way of equipment |
| Larger or high-spec fit-outs | Ducted units | Only grilles on show; can be paired with the fresh air system |
| Multi-room sites and leisure centres | VRF | Many indoor units on one refrigerant system, each zone controlled separately |
Placement matters as much as the type. We keep air off the faces of people on fixed machines, avoid blowing straight onto mirrors and screens, and keep indoor units away from dumbbell racks and anything that could be thrown or swung.
Noise, studios and the outdoor units
On a busy weights floor, music and equipment will usually drown out the air conditioning. Yoga, Pilates, stretching and treatment rooms are different. For quiet rooms we choose indoor units with low fan speeds, comparing the manufacturer’s published sound data.
The outdoor units are often the bigger question. They need airflow, clearance set out in the manufacturer’s installation manual, a solid base or brackets, and a route for the refrigerant pipes. On a high street or industrial unit they often go on a flat roof or in a rear yard. We check what neighbours are close by, because planning permission for cooling plant on commercial premises is a matter for the local council, and a landlord’s consent is usually needed on a leased unit.
Want it done properly? AirCon Doctor installs, repairs and services air conditioning and heat pumps across London and the South East, from our base in East Grinstead. We’re an F-Gas certified company and NICEIC approved. Get a fixed-price quote.
Condensate and humidity
A gym system produces a lot of condensate. Every indoor unit needs a reliable way to get that water away: a gravity drain with a proper fall where possible, or a condensate pump where there’s no fall. Pumps need to be quiet enough for the room and accessible for cleaning, because a failed pump in a ceiling void means water through the tiles. We also make sure drains discharge somewhere suitable, not onto a path where it can ice over or grow algae.
If damp persists, we look at the ventilation rate and controls before adding capacity: an oversized system that cycles on and off can leave the air damper.
What we check at a gym site survey
- Floor areas, ceiling heights and what’s above the ceiling (void depth, services, access).
- Peak class sizes and opening hours, plus which rooms are hard workouts and which are quiet.
- Glazing and orientation: a glass shopfront facing south is a large heat gain.
- Existing ventilation, its fresh air rate and changing room extract.
- Electrical supply and distribution board capacity for the new circuits.
- Outdoor unit positions, pipe routes, condensate routes and roof or yard access.
- Lease terms, landlord requirements and any planning questions.
- When we can work: most gyms want installation planned around opening hours.
From that we produce a fixed-price quote with the equipment, positions and programme set out.
F-Gas, TM44 and maintenance
As the operator of the equipment, the gym has legal duties. Systems with 5 tonnes CO2 equivalent or more of refrigerant need leak checks at least every 12 months (every 6 months from 50 tCO2e), with records kept. A tonne of CO2 equivalent is the refrigerant charge in kg multiplied by its global warming potential, divided by 1,000. R32 has a GWP of 675 under Annex I of Regulation 517/2014, so a 3 kg R32 system is about 2.0 tCO2e and below the threshold, while larger multi-room and VRF systems often cross it.
If the total effective rated output of the air conditioning in the building is more than 12 kW, the building also needs an air conditioning energy inspection by an accredited energy assessor, no more than five years apart. Our TM44 page explains how we prepare for those.
Whatever the size, a gym system works hard and benefits from regular servicing: filters cleaned, coils cleaned, drains and pumps checked, and refrigerant performance checked. Many gyms choose a maintenance contract so visits happen on schedule without anyone having to remember.
What it costs
Gym projects vary too much for a single figure, so commercial systems are priced after a survey. As a guide, a single-room wall-mounted split for a small studio falls in our standard range of £1,200 to £2,200 + VAT, including supply, installation, commissioning and F-Gas documentation. Multi-room systems, cassettes, ducted units and VRF are quoted at a fixed price once we’ve seen the site. Businesses pay the standard rate of VAT. See our commercial air conditioning and gym and leisure pages for more.
Quick answers
Can domestic air conditioning units be used in a gym?
Small studios sometimes use the same wall-mounted splits found in homes, but busy gyms need equipment sized for peak occupancy and long hours, plus a separate fresh air system. We specify from the manufacturer’s commercial and light commercial ranges where the load calls for it.
Does air conditioning provide fresh air in a gym?
Usually not. Wall-mounted, cassette and most ducted indoor units recirculate room air. HSE says recirculating systems should be designed with fresh air inlets, so we plan ventilation alongside the cooling.
What temperature should a gym be kept at?
There is no legal maximum. HSE says employers must provide a reasonable temperature and its code suggests at least 13°C where work involves rigorous physical effort. Most gyms set a cool target for workout areas and a warmer one for quiet studios.
Does our gym need a TM44 inspection?
If the air conditioning in the building has a total effective rated output of more than 12 kW, yes: an accredited energy assessor must inspect it at least every five years.
Related services
- Gym and leisure air conditioning
- Commercial air conditioning
- Ventilation systems and MVHR
- Cassette air conditioning
- Air conditioning maintenance contracts
More advice
- Air Conditioning for Offices: What You Need to Know
- Air Conditioning Maintenance Contract: What It Includes and Is It Worth It?
- How to Choose the Right Size Air Conditioning Unit
- Can Air Conditioning Improve Air Quality?
- All advice
This guide is general information, checked against the sources linked on 30 October 2026. It isn’t legal, tax or financial advice. Rules, grants and product ranges change, so check the current position before you rely on it.