Can I install air conditioning myself?
A straight answer to the question, with the two laws that decide it and what you can legally do without either.
- REFCOM certified, REF1025662
- Daikin registered installer
The short answer
Not a fitted wall mounted system, no. Two separate laws stop it and both apply to a normal domestic install. The refrigerant is a fluorinated gas, and the government's guidance says plainly that it is against the law to work with F gas without the correct qualifications, with a civil penalty for doing so. You will also struggle to buy the equipment: before selling a non hermetically sealed system a retailer must ask for the details of the qualified technician who will install it, in writing, and check those details are valid. Separately, a 5.0kW unit needs its own circuit from your consumer unit, and installing a new circuit is notifiable work under Part P of the Building Regulations in England. What you can do without any qualification is buy a portable unit, because those are sealed at the factory.
The refrigerant is the first problem
A wall mounted air conditioner is a split system: an indoor unit, an outdoor unit, and a sealed circuit of refrigerant running between them. Connecting that circuit is the part that needs qualifications, and it is not a formality.
The government's guidance is unusually direct about it. It states that you must have your own qualifications to work on equipment containing F gas, even if you work for someone else, and that it is against the law to work with F gas if you do not have the correct qualifications, with a civil penalty for breaking that law. It also gives an email address for reporting people working on F gas without them.
The refrigerant in a modern domestic system is usually R32, which has a global warming potential of 675. That is the reason the rules exist. A badly made joint that vents its charge is not just an expensive fault, it is a release of greenhouse gas several hundred times more potent than carbon dioxide.
What the qualifications actually are
Two different things, and a competent installer holds both. A personal qualification covers the individual doing the work. A company certification covers the business.
| What it covers | Who needs it | |
|---|---|---|
| Category 1 certificate | All activities on refrigeration, air conditioning and heat pump systems, with no charge size limit | The engineer, personally |
| Category 2 certificate | Install, maintain, service and recover refrigerant from systems under 3kg of F gas, or under 6kg if hermetically sealed | The engineer, personally |
| Company certification | Required for a business to work on these systems for others, renewed every three years | The company |
From the government's guidance on qualifications and company certification for working with F gas. NVK Air holds Category 1 personally and REFCOM company certification REF1025662.
You will also struggle to buy the equipment
This is the part that surprises people. The duty does not only sit on the installer, it sits on the seller. Before selling non hermetically sealed equipment containing F gas, a retailer must ask the end user for the details of the qualified technician who will install it, should get those details in writing, and must check that the technician's details are valid. A split system is not hermetically sealed, so a seller following the law cannot simply put one in a homeowner's van. If a supplier offers to sell you one with no questions asked, that tells you something about the supplier rather than about the rules.
The electrics are a second, separate problem
Even if the refrigerant side were solved, the electrical work is regulated on its own terms, and the threshold lands right in the middle of a normal domestic job.
A 2.5kW or 3.5kW unit runs off a fused spur. From 5.0kW up it needs its own circuit from your consumer unit, and in England the installation of a complete new circuit connected to the consumer unit is notifiable work under Part P of the Building Regulations. Notifiable means it has to be notified to a building control body in advance so it can be inspected, or carried out by someone registered with a competent person scheme who can self certify it.
So the moment a job is a living room rather than a bedroom, a second set of rules applies. That is not an obstacle we invented to sell a service, it is where the threshold happens to sit.
What it actually costs to get wrong
Not scare stories. These are the four things that bite, in the order people meet them.
The manufacturer's warranty
Every manufacturer we fit requires installation by a qualified person and commissioning records. An uncertified install is not a warranty claim waiting to happen, it is simply not covered, and the unit is the expensive part.
Your home insurance
Insurers ask whether work was carried out by a suitably qualified person. Water damage from a condensate line, or a fire traced to an unnotified circuit, is where that question gets asked and it is a bad moment to find out.
Selling the house
A buyer's solicitor asks for certificates for notifiable electrical work. Not having one is not fatal, but it becomes a retention or a price reduction at the worst possible moment, and a regularisation certificate after the fact costs more than doing it properly did.
The civil penalty
The one people discount. Working with F gas unqualified is an offence with a civil penalty attached, and the Environment Agency publishes an address for reporting it.
What you can legally do yourself
A portable air conditioner. Those are hermetically sealed at the factory, which means the refrigerant circuit is permanently closed and tested to leak less than 3 grams a year, and the government's own guidance exempts hermetically sealed equipment from the checks a seller has to make. You can buy one, plug it in and use it today with no qualification of any kind.
We do not sell them and we are not going to pretend they are as good. A portable is louder because the compressor is in the room with you, it is less efficient, it needs a hose out of a window that lets warm air back in, and it does not heat your house in winter the way a reversible system does. But it is a legitimate answer for a rented flat, a room you cannot alter, or a single hot fortnight, and anybody telling you otherwise is selling.
What you cannot do is buy a split system and fit it at the weekend. That is the honest line, and it is drawn by legislation rather than by us.
What to ask whoever you do use
If you are getting quotes, the credentials are checkable and you should check them. Ask for the company's F gas certification number and the body that issued it, and ask whether the engineer holds Category 1 or Category 2, because Category 2 is limited by charge size.
Ask who is doing the electrical work and, on a 5.0kW or larger unit, how the new circuit is being certified. A firm that cannot answer that second question quickly has not thought about the part of the job that ends up on your paperwork.
For the record, ours are REFCOM company certification REF1025662 and F Gas Category 1, and the electrical connection is carried out by a qualified electrician as part of the quoted price rather than as an extra.
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