One Room or the Whole House, the Constraint Is Pipework

Room count is not usually what limits a domestic system. Pipe run is. A standard three-zone Mitsubishi or Daikin multi-split handles around 30 metres of total pipework, and the height difference between the indoor units and the outdoor condenser counts towards it. In a three-storey Hendon semi, that figure decides whether one outdoor unit will serve the house or whether you need two.

One room, one unit. Pairing a single indoor unit with one outdoor condenser suits a bedroom, a home office or a south-facing living room. It is the usual starting point in a Hendon house, and a single split system can be added to later.

Several rooms, one condenser. Linking two to five indoor units back to a single outdoor unit keeps the outside of the property tidy. That matters on a period frontage where a second box would be hard to hide.

Flats and newer builds. Balcony and flat-roof siting are both workable off Aerodrome Road and Great North Way. Leasehold consent is often the real hurdle rather than the engineering, and we tell you what to ask your freeholder.

Hendon sits inside our wider North West London coverage, so the same team covers Golders Green, Colindale and Mill Hill.

Brent Street Retail and Offices Have Different Rules

Hendon’s commercial spine runs along Brent Street and Hendon Central, taking in the Sentinel Square shops and serviced office space at Foframe House. Premises there usually need cooling that works through trading hours and stays quiet enough not to trouble the flats above.

One legal point catches out a lot of landlords and managers. Any air conditioning system with an effective rated output above 12kW must have a TM44 inspection, which assesses how efficiently the system is actually running. Our engineers are qualified to carry those out and to issue Energy Performance Certificates.

– Shop and restaurant cooling that runs through trading hours

– Office systems zoned by floor or by meeting room

– Ceiling cassettes where wall space is taken by stock or display

– Server and comms room cooling on small business premises

For larger sites, we handle commercial system design and installation from survey through to commissioning.

Nobody Can Quote Your House Without Seeing It. Here Are the Ranges Anyway.

Across the UK in 2026, a single-room split system typically costs between 1,500 and 3,000 pounds fitted. A two-room multi-split runs around 2,800 to 4,500 pounds, and a three or four room system around 3,500 to 7,000 pounds. Ducted systems for a whole house start higher again, from roughly 6,000 pounds. London and the South East usually sit 10 to 25 per cent above those figures, because labour and access cost more here. Those are published industry ranges rather than our prices, and yours is confirmed after a survey.

Four things move the number more than anything else. Pipe run length and routing come first, because a long or awkward route means more labour and more copper. Unit count is second. Access is third, and reaching the top floor of a three-storey Hendon semi changes the day. Brand is fourth, with Mitsubishi Electric and Daikin sitting above Toshiba and LG for the same kW output.

One cost people forget to compare is certification. The refrigerant side of a split system has to be fitted by an F-Gas certified engineer by law, so a DIY install is not lawful and an uncertified quote is not a like-for-like comparison. Proper F-Gas installation typically adds 200 to 400 pounds over a quote from someone without it.

Running costs are easier to pin down. Under the Ofgem price cap for 1 July to 30 September 2026, electricity is 26.11p per kWh. A 2.5kW inverter split drawing around 0.75kW costs roughly 18p to 21p an hour to run.

Once It Is In, It Needs Looking After Once a Year

An annual service runs roughly 80 to 150 pounds per system nationally, and closer to 120 to 180 pounds per indoor unit in London postcodes. The visit covers filter cleaning, a refrigerant check, a condensate drain check and a performance test.

Most customers book seasonal servicing in spring, before the first warm spell puts the system under load. If something has already failed, a breakdown diagnosis visit finds the fault first, so you are not paying for parts on a guess.