Split air conditioner installation
Updated: October 2026
Split air conditioner installation becomes a regulated job as soon as a refrigerant circuit must be connected, opened or altered. A pre-gassed wall kit is not a legal shortcut. You can plan the position and prepare questions, but a properly qualified person must carry out the refrigerant work. A sealed portable split is the narrower exception, because normal temporary setup leaves its circuit intact. Before you order from our [split air conditioner comparison](/hub/cooling/split-air-conditioner), agree who will install it, check planning for the property, and establish whether the electrical or fixed-system work must be notified. We did not run a lab test. A purchase through our links may earn a commission at no extra cost to you.
Split air conditioner installation becomes a regulated job as soon as a refrigerant circuit must be connected, opened or altered. A pre-gassed wall kit is not a legal shortcut.
Split air conditioner installation becomes a regulated job as soon as a refrigerant circuit must be connected, opened or altered. A pre-gassed wall kit is not a legal shortcut. You can plan the position and prepare questions, but a properly qualified person must carry out the refrigerant work. A sealed portable split is the narrower exception, because normal temporary setup leaves its circuit intact. Before you order from our split air conditioner comparison, agree who will install it, check planning for the property, and establish whether the electrical or fixed-system work must be notified. We did not run a lab test. A purchase through our links may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Type | Who connects it | Heating claim | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Midea Midea PortaSplit 12,000 BTU | Portable split | Temporary setup, circuit stays sealed | Heat pump | 9.2 | about £1,099.99 | View offer |
| Preis-Tipp |  Generic Generic 12,000 BTU wall split AC12000 | Wall split | Pre-gassed for a qualified fitter | Heat pump | 7.8 | about £500 | View offer |
| Alternative |  Generic Generic 24,000 BTU wall split WC18 | Wall split | 3 m kit, qualified fitter | Heat pump | 6.5 | about £849.99 | View offer |
On this page
Two ways a split gets into a home
A wall split has an indoor evaporator, an outdoor condenser and pipes through the building. Even with pre-charged pipework, making those connections is work on F-gas equipment. Easy install does not move those duties onto an unqualified buyer.
A sealed portable split arrives with the sections connected. The Midea PortaSplit can be set up temporarily without a technician in normal use: place the outdoor part safely outside and route the factory connection through a suitable opening. That exception ends if you fix it permanently or extend the hose. Midea then says a qualified installer is required. A copper pipe kit is not the same thing as a sealed portable, even if both say pre-gassed. Capacity and heating sit in the split air conditioner buying guide.
What an F-gas certificate covers
Stationary air-conditioning work involving F-gas needs an appropriately qualified person. GOV.UK identifies Category 1 for the full range of relevant activities. Category 2 is limited to equipment containing less than 3 kg of F-gas, or less than 6 kg if the system is hermetically sealed. When an engineer works for you through a business, the company also needs certification.
Before non-hermetically sealed equipment is sold to an end user, the seller needs evidence of the certified installer. Hermetically sealed means permanent joints and a tested leakage rate below 3 g per year. A wall split with a copper pipe kit is generally not hermetically sealed because the outdoor unit is pre-charged.
Contact installers before you buy. One AC12000 reviewer found no firm willing to fit a customer-supplied unit. Do not open the pipework yourself. Pre-gassed does not waive the certificate. Conditional picks are in the best split air conditioner guide.
Planning permission in England
Planning and an F-gas certificate answer different questions. The certificate controls who may work on the refrigerant. Planning controls whether the unit may be installed there. In England, a cooling-only outdoor unit sits outside the permitted-development route that can apply to a heat pump. The Planning Portal advises that cooling-only air conditioning needs an application.
For a system that heats and cools, England’s Class G can apply. Outdoor-unit volume is limited to 1.5 m³ for a house and 0.6 m³ for a flat, with the applicable MCS planning standards. That is not automatic approval, and the unit must not be solely for cooling. Listed buildings and conservation areas can add restrictions. These Class G details are for England. Scotland, Wales and Northern Ireland have their own systems, so do not copy the English volumes into a UK-wide decision.
Building regulations, then stop
Planning permission asks whether the development may proceed. Building regulations govern how the work is carried out. In England, installing a fixed air-conditioning system is notifiable unless a competent-person installer can self-certify it. A new electrical circuit is separately notifiable under Part P. The refrigerant qualification does not automatically cover structure, drainage or electrics.
Confirm the room load and the positions, check planning, appoint the certified trades, and only then order the accepted model. Stop if the job needs refrigerant connections, permanent fixing, a hose extension, a new circuit, listed-building work, or a disputed spot near a neighbour. For a PortaSplit in normal temporary use, follow the securing instructions and do not improvise an extension. That plug-in path does not make a pipe-connected wall split a DIY job.
Common questions
Can I install a wall split myself?
You may plan positions and carry out work that is lawfully within your competence. You must not connect or open the F-gas refrigerant circuit without the required qualification. Fixed-system work, drilling, drainage and a new electrical circuit can add planning, building-control and Part P duties. Easy install on a listing does not move those duties onto an unqualified buyer.
Does pre-gassed mean DIY installation?
No. Pre-gassed means refrigerant is already in part of the packaged system. A wall split still needs qualified work when its refrigerant pipes are connected or commissioned. The label also does not prove that the supplied pipe length, the electrical arrangement or the brackets suit your property. Do not open, cut or extend the pipework yourself.
What does hermetically sealed mean?
For the sale rules, it means the refrigerant-containing parts use permanent joints and meet a leakage-rate threshold below 3 g per year. A factory-connected portable split may keep that sealed circuit in normal temporary setup. A wall kit with copper connections is not made hermetically sealed by a pre-gassed label, even if the outdoor unit arrives charged.
Does a cooling-only unit need planning permission in England?
The Planning Portal says cooling-only air conditioning falls outside the permitted-development rights that can apply to a system which also heats, so an application is needed. Listed buildings, conservation areas and local constraints need particular care. Ask the local planning authority before you purchase. A quiet operating mode is not a substitute for that check.
Do England’s Class G rules apply across the UK?
No. Class G, and the cited limits of 1.5 m³ for a house and 0.6 m³ for a flat, concern England. The unit must also heat, not cool only, and approval is not automatic. Scotland, Wales and Northern Ireland operate different planning systems. Check the rules for the nation and the council where the equipment will be installed.
Can I set up a Midea PortaSplit without an engineer?
Midea says normal temporary setup needs no technician because the connection remains sealed. You still need a safe outdoor position within about 2 m, and you must follow the securing instructions. If you fix the system permanently or extend the hose, a qualified installer is required. That plug-in path does not apply to a pipe-connected wall split.
Related pages
Sources
Public UK sources and the manufacturer page below. amazon.co.uk listings checked on 15 October 2026.
- GOV.UK: qualifications required to work on equipment containing F gas (retrieved 15 October 2026)
- GOV.UK: selling F gas or equipment (retrieved 15 October 2026)
- Planning Portal: planning permission to add air conditioning (retrieved 15 October 2026)
- legislation.gov.uk: England GPDO Class G (retrieved 15 October 2026)
- GOV.UK: building work, replacements and repairs to your home (retrieved 15 October 2026)
- legislation.gov.uk: Regulation (EU) No 206/2012 (retrieved 15 October 2026)
- legislation.gov.uk: Regulation (EU) No 626/2011 Annex III (retrieved 15 October 2026)
- GOV.UK: noise nuisances and how councils deal with complaints (retrieved 15 October 2026)
- Midea UK: PortaSplit air conditioner (retrieved 15 October 2026)