Nesta, the research and innovation foundation, said at an online event on 25 August 2026 that it will launch a heat planning tool in February, designed with and for local authorities1. The announcement came during a webinar on air-to-air heat pumps, held as part of the organisation's sustainable future work1.
"We're launching a heat planning tool in February designed with and for local authorities"
The event drew on a Nesta report published at the start of this year, which included interviews with 16 homeowners, eight installers and eight non-installer experts, alongside desk research on manufacturer data sheets, forums and scientific papers1. Nesta said air-to-air heat pumps could work in "pretty much all different UK homes", with the main constraint being the need for an outdoor unit, although it noted that fully internal ducted units are in development1. It said some units can put out over 7 kilowatts, making them suitable for smaller open-plan properties where few internal heads are needed1.
On running costs, one contributor said she spent £170 this summer for a 3.5 kilowatt unit1. Nesta also cited figures "floated around saying that 5% of UK homes have air conditioning"1. On cooling performance, it said that for many of the units tested, output falls away at around 35 degrees C1, and that a 2.4 kilowatt battery charged by solar during the day is "probably sufficient to cover a flat's cooling load on a very hot day in the evening"1.
The event also covered refrigerant rules. Nesta said the Kigali Amendment in 2016 set out phase-down schedules and baseline years1, and that some air-to-water heat pumps containing refrigerants with a global warming potential above 150 will be banned from 2027, with some air-to-air heat pumps containing HFC refrigerant banned from 20291. A speaker referred to a date of "the 27th" as the point at which something becomes legal in the UK, without stating the month or year1.
On grants, Nesta said those seeking the Boiler Upgrade Scheme grant or going down the MCS route will require full decarbonisation, and the boiler will have to be removed1. It noted that permitted development allows for only one outdoor heat pump unit, apart from in detached homes1. Nesta said it is going to do testing at the Salford Energy House on air-to-air units used intermittently versus continuously1.
Why it matters for households
Air-to-air heat pumps provide both heating and cooling from the same unit, which matters for homes weighing up how to cut reliance on gas1. Nesta's finding that they can suit most UK homes, including smaller open-plan properties, is relevant to households that cannot easily accommodate the radiators and hot water cylinder an air-to-water system needs1. The refrigerant phase-down dates mean the equipment available to households will change over the next few years, with air-to-water units affected from 2027 and air-to-air units from 20291. The planning rules on outdoor units, and the grant conditions requiring boiler removal, shape what a household can install and claim1. The regulation-policy hub covers the wider rules affecting home energy installations.
What happens next
Nesta said the heat planning tool will launch in February1. It also said testing at the Salford Energy House on intermittent versus continuous use of air-to-air units is planned1. No further dates for either were given in the material published on 25 August 20261.