Thermal insulation paint first entered the energy saving market back in the late 1990's. Since then, there has been an increase in companies looking to exploit the seemly attractive potential in insulating paint.
Insulating paint is said to consist of honeycomb or ceramic hollow balls supposedly invented by NASA, which don’t just slow down the heat transfer through the walls but actually stops it all together! Therefore the heat has no choice but to go back into the room. This means that your rooms don’t take as long to heat up and you don’t have to have your boiler on for as long. https://www.thegreenage.co.uk/does-insulation-paint-work/
Typical insulation involves insulating cavity walls or utilising internal or external wall insulation boards. The issue with internal wall insulation is that it reduces the size of the room. As building regulations change, the U-Values of the wall need to change which requires a thicker insulation board.
Insulating paint is nowhere near the thickness you require with internal wall insulation, yet many companies claim that their product still offers 25% savings on customers heating bills. As paint is only applied to around a millimetre thick, these are truly incredible results – but are they true?
“Scientific studies show” is a go-to phrase used by the insulating paint market. When Alex Wilson, a well-known sustainability expert, was asked about the claims that insulating paint generates savings in domestic homes, he stated “they are making claims that defy the laws of physics”. It is claimed that thermal insulation paint works in a different way to traditional insulation techniques, in that it prevents heat from leaving the room. This would actually cause a build up of condensation as opposed to solving the problem. Condensation in a home can make it feel cooler not to mention the damage it causes to the fabric of the building and health to it's occupants. https://www.thegreenage.co.uk/does-insulation-paint-work/
You can read many articles both pro and con about insulating paint. I can not say either way as I have not used the product myself. I can tell you traditional wall insulation products work and work very well. My home was built in 1877, it is solid brick construction (solid brick has a very poor U-Value). I had external wall insulation fitted and it has had incredible results! The average temperature in my home in the winter is 18 c with no heating on. This is due to appliance, lights, and people generating heat in the home. My heating system is rarely on this I have extremely low utility bills. In the summer when it is hot (warm) the home stays cool. The wall insulation keeps the heat out as well.
Internal wall insulation is may not be suitable in some period properties due to the architectural features in the home. These properties always have a solid stone or brick wall construction . External wall insulation may not be allowed due to planning or conservation rules.
You can find thermal wall paint on Amazon www.amazon.co.uk and various other web sites, it is not in short supply.
So I guess we are no farther on with thermal paints. If you have used thermal paints and have a review on the product, please me know. If these products work and do not cause condensation issues we need to look at them as an alternative to wall insulation.