- Prices and running costs
- Winter heating
- Fitting
- Estates, flats and planning
- Servicing and faults
- Where we go
Prices and running costs
How does pricing work?
Give us a postcode and the room, by form or on 01322 952910. We ring you, and when the job looks feasible we arrange a survey and follow it with a quote in writing.
What is a fitted wall unit likely to cost?
Nationally, Checkatrade (May 2026) lists a 12,000 BTU unit at £750 and the fitting at £1,150, with another £400 to £700 for the electrics. The cost guide breaks every part of that down.
How much electricity does it use?
Checkatrade puts it at 20p to 60p an hour. Using the present price cap, a 2.5kW unit holding a room at temperature works out near 9p an hour; the sum is in the cost guide.
Two quotes, very different totals. Why?
Look for what the cheaper one leaves out: the electrics, access equipment, extra pipe, the consents or a company F-gas certificate. Only when all five are in both can you compare them.
Winter heating
Does the unit heat as well as cool?
A reversible one does, by running its cycle the other way to warm the room it is in. Details under air-to-air heat pumps.
Is it cheaper to run than electric heaters?
Considerably. With a seasonal efficiency of 4, a kilowatt-hour of warmth costs around a quarter of the price a plug-in heater charges for the same heat.
Will it do the hot water?
No. Showers and taps remain with the boiler or the cylinder.
Fitting
How powerful a unit does my room need?
Roughly 2.0 to 2.5kW for 15 to 25 square metres, with extra for a lot of glass, a high ceiling or a loft. The size guide has the table.
Is a dedicated circuit needed?
Almost always, and because adding a circuit to a home is notifiable under Part P, a registered electrician installs and certifies it.
Can one outdoor unit serve two rooms?
Yes, through a multi-split, the normal layout for a semi or a terrace that is allowed one outdoor unit.
Is a loft room possible?
Usually, where there is a gable or dormer wall for the indoor unit and a way down for the pipes. The loft guide goes through it.
What if the freeholder forbids anything on the outside?
A monobloc works through two grilles in the wall and has no outdoor box. This guide explains how it performs and where it falls short.
Would a portable do the job?
In a rented room or as a stopgap, quite possibly. Our comparison does not pretend otherwise.
Estates, flats and planning
Our estate has a management company. Where do we start?
With the deeds or the management company's rules, and with a check on whether the estate's original planning permission stripped out permitted development rights. We examine both before the survey.
My flat is leasehold. Whose consent do I need?
The freeholder's, in writing, before anyone measures anything. What they may refuse and what they may charge is set by the lease. See air conditioning in a flat.
Do I need planning permission?
Not for a reversible unit on a house that satisfies all the permitted development conditions. Flats over shops, listed buildings and road-facing walls inside conservation areas do need it. See the planning guide.
What difference does a conservation area make?
The unit may not go on any wall or roof that faces the road, nor anywhere between the house and the road. Dartford has six conservation areas and Bexley 23.
Will the neighbours complain about the noise?
Not if the sums are right: for permitted development the calculated sound at their nearest window must be 37 dB(A) or below, and we give you that figure in writing.
Servicing and faults
How often does it need a service?
Yearly for a home, ideally in spring. A busy shop or salon may want two visits. See servicing.
Why is water coming out of the indoor unit?
Almost always a blocked condensate drain or a dirty coil. Turn it off and ring; it is a quick repair.
Could you just add some gas?
No. A sealed system should keep its charge, so if it is low there is a leak, and the leak is what we fix.
Do you maintain systems other companies installed?
Yes, whatever the make. The label on the indoor unit tells us what we need to know.
Where we go
Where do you work?
Dartford and the DA postcodes, the Bexley side from Crayford round to Sidcup, Gravesend and Northfleet, and Swanley. Every town is on the areas page.
Do you go over the bridge to Thurrock?
Not normally. Send the postcode and we will give you a straight answer.
Can I write rather than call?
Yes. The email address is on the quote page, and the form on that page reaches the same inbox.
Worth knowing before you ring
With these we can usually tell you on the first call whether the job is simple.
- The postcode
- Whether it is a house, a flat or business premises, and roughly its age
- If you rent or lease, who owns the external wall
- Which room, how big, and the direction its window faces
- Any management company, conservation area or listing that applies
Want us to ring you?
Question not here? Leave your number and we ring back with the answer. Or ring 01322 952910.