commercialhvacuk
Get a Quote

Commercial portable air conditioning: when it works and when it doesn't

Updated 23 October 2026 · SEO Dons Editorial

Is portable air conditioning illegal in the UK?

No. The legislation and guidance checked on 22 October 2026 contain no rule that bans owning or using a portable air conditioner in a workplace. What exists is a set of product rules, most of which fall on whoever supplies the unit, plus electrical and refrigerant duties that can fall on the user.

RuleWhat it saysMainly affects
F-gas product banGOV.UK lists movable air conditioning equipment, which the user can move between rooms, with HFCs above a GWP of 150 as banned now. Annex III of the retained F-gas regulation gives 1 January 2020Suppliers placing units on the GB market
Scope of that banArticle 11 prohibits placing products on the market, meaning supplying them to another party. It does not order units already supplied to be removedSuppliers and importers
Ecodesign and energy labelBoth regulations cover electric mains-operated air conditioners up to 12 kW. Single and double duct units must meet a minimum EER and an indoor sound power limitSuppliers and dealers, including for hire
Leak checksThe regulation's "stationary" includes moveable room air-conditioning appliances, so the check rules can apply where the charge is large enoughUsers, or the hire company, depending on the rental agreement
Electrical safetyEmployers must keep electrical equipment maintained to prevent danger; the law sets no test intervalEmployers and hire suppliers

The wider question of whether any air conditioning is being restricted is answered in the guide to whether air conditioning is being banned.

What counts as a commercial portable air conditioner?

Two designs sit under the name. A monoblock unit holds the whole refrigeration circuit in one cabinet and sends the heat it removes outside through a hose. The labelling regulation separates two kinds: a single duct unit takes its condenser air from the room and discharges it outside, while a double duct unit brings that air in from outdoors by a second duct. A mobile split unit has a separate outdoor unit joined by a refrigerant line, so the heat is rejected at the condenser outdoors. The guide to how commercial air conditioning works explains the cycle behind both.

DesignHow heat leavesOne manufacturer's declared data
MonoblockExhaust hose to the outside3.5 kW maximum cooling, 1,600 W power consumption, R290 at 230 g (GWP 3), 1,500 mm hose with a 153 mm connection
Mobile splitOutdoor unit, joined by a refrigerant line3.5 kW maximum cooling, 1,200 W power consumption, R32 at 640 g (GWP 675, 0.432 t CO2e)

Those are two models from one supplier, shown to illustrate what a datasheet declares, not to rank products. GOV.UK treats split systems separately: it describes a single split as a system with one cooling coil connected to a remote condensing unit, with its own limits. Which product rule a given unit was placed on the market under depends on how the supplier classes it, so ask for that in writing.

When does portable cooling work well?

  • Temporary cover while fixed plant is repaired or replaced.
  • A stopgap for a small equipment room while resilient cooling is arranged. The server room cooling requirements cover temperatures, sizing and backup.
  • One hot room where fixed work is not possible, for example because of lease terms. Check the lease and the landlord's consent first.
  • Events and trials that last days or weeks rather than years.

In each case the rating is a maximum, so total the heat sources first. The sizing guide shows how.

When does it not work, and why?

The heat has to go somewhere. The manufacturer above says the heat from a monoblock must be led outside without mixing again with the indoor air, and that at least one exhaust hose is necessary. A hose that ends in a ceiling void or corridor leaves the heat in the building. A single duct unit also takes its condenser air from the room, so the same volume of air has to be replaced from somewhere else.

Water needs a plan. The monoblock datasheet lists a maximum dehumidification capacity of 3.38 litres an hour and a condensation tray or drain. The split model pumps its condensate to the outdoor unit instead.

Noise is quoted several ways. The ecodesign limit for single and double duct units is an indoor sound power level of 65 dB(A). The monoblock datasheet gives 64 dB(A) as sound emission to EN ISO 3745:2012 and 54.5 dB(A) at 1 m. Ask which figure a comparison uses.

Running cost needs checking. For single and double duct units the minimum rated EER is 2.4 where the refrigerant GWP is above 150 and 2.16 where it is 150 or less. The monoblock example delivers 3.5 kW for 1,600 W, a ratio of about 2.2. As an illustration only, assume a fixed system works at a seasonal ratio of 4.0. EER and seasonal ratios are measured differently, so this is not a test result. Even so, 100 hours of 3.5 kW cooling would need about 160 kWh at 2.2 and about 88 kWh at 4.0. Multiply the gap by the unit rate on your own bill.

What should you check before hiring or buying?

  1. Design and exhaust route. Single duct, double duct or split; hose length and diameter; window, wall or ceiling kit; where condensate goes.
  2. Refrigerant and classification. Read the gas type and charge on the data plate, and ask which F-gas product rule applies. If the charge is large enough, the leak-check thresholds are 5 tonnes of CO2 equivalent, or 10 tonnes for hermetically sealed equipment. The rental agreement can shift leak-check responsibility.
  3. Documents. Suppliers must provide a printed label with each air conditioner, and dealers marketing units for sale or hire to customers who cannot see the product must pass on the supplier's information. Ask the hire company for the label and product fiche.
  4. Electrical supply. HSE recommends that suppliers inspect and test equipment before each hire. Confirm the circuit can carry the load, as set out in the electrical supply guide, and keep the lead out of walkways.
  5. How long you need it. Compare the cost of repeated cover with a fixed system using the hire versus buy guide.

A fixed system designed and zoned for the building is the usual answer when the need is permanent, as the office air conditioning page explains. Readers who want one assessed can send an enquiry through the site's form.

Sources

Common questions

Do hired portable units come with an energy label?

The labelling regulation requires suppliers to provide a printed label with each air conditioner up to 12 kW. It also requires dealers marketing units for sale or hire, where the customer cannot see the product, to pass on the supplier's information. Ask the hire company for the label and product fiche.

Does a propane refrigerant fall under the F-gas rules?

The F-gas regulation defines fluorinated greenhouse gases as HFCs, perfluorocarbons, sulphur hexafluoride and other fluorine-containing gases. One manufacturer describes R290 as propane, a hydrocarbon with a GWP of 3, so it is not an HFC. A flammable refrigerant has its own safety considerations, which the R290 air conditioning guide on this site covers.

What changes for units above 12 kW?

The ecodesign and labelling regulations cited here cover air conditioners with a rated capacity of 12 kW or less for cooling. A larger mobile cooler sits outside those two regulations, although other product rules can apply to larger plant, as the SEER guide explains. Electrical safety duties still apply.

Does a portable air conditioner always need a window?

A monoblock needs an exhaust route to the outside, and its manufacturer says at least one hose is necessary. A mobile split places its outdoor unit outside, so it needs a position for that unit and a route for the connecting line. Any wall or ceiling route should be agreed with the building owner first.

Ask for commercial HVAC quotes

SEO Dons Ltd publishes this site and replies to every enquiry by email. It does not install, service or maintain HVAC.

Get a quote
Get a quote