Technology
Heat pumps
Two different machines share this name. An air-to-water heat pump feeds radiators and hot water and heats only. An air-to-air heat pump is a reversible air conditioner and does both. They carry different grants and different rules, so this site never says heat pump without saying which.
The units
3 in the database, every figure copied from the manufacturer's own specification page with the date somebody read it. Nothing has been bought, run or measured, so there are no scores.
Air-to-air heat pump, reversible
- MSZ-AP25VGK with MUZ-AP25VG outdoor unit Mitsubishi Electric
- MSZ-AP35VGK with MUZ-AP35VG outdoor unit Mitsubishi Electric
- MSZ-AP50VGK with MUZ-AP50VG outdoor unit Mitsubishi Electric
Writing
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What should be in an air conditioning quote
Choosing and fitting
A quote with one number on it is not a quote. What the survey should have covered, how many units you actually need, and what to settle before signing.
David White -
What the state pays towards a heat pump, and the catch on all of it
Choosing and fitting
£7,500 for air-to-water, £2,500 for air-to-air, £1,500 more if you are off the gas grid on oil or LPG. Every one of them runs through MCS.
David White -
What the October 2026 price cap changes about what you run
Your Home
Electricity loses its VAT and gas rises 8% from 1 October. The verified rates, and the point where a heat pump becomes cheaper than a gas boiler.
David White -
Fitting air conditioning in a flat, and why the lease decides
Choosing and fitting
In a flat the planning rules are the easy half. The lease, the freeholder and who owns the external wall decide whether a split system is possible.
David White -
Air conditioning now qualifies for a £2,500 government grant
Choosing and fitting
Air-to-air heat pumps joined the Boiler Upgrade Scheme on 28 April 2026. A cooling-only unit does not qualify, and neither does a non-MCS installer.
David White -
The planning rule that decides what air conditioning you can fit
Choosing and fitting
In England a unit that only cools is never permitted development, at any size, in any position. One that also heats often is. Most sites miss this.
David White