Has anyone retrospectively fit aircon in a loft conversion?

[redjam]

OK so we are having our annual conversation about getting aircon fitted, as our west-facing loft turns into an ACTUAL FURNACE whenever the temperature goes over 25 degrees. (It's 33 degrees in here now and that's with the blackout blinds closed all day.)

We have Velux windows that are hinged in the middle so I think a portable unit is out of the question as it would be a nightmare with the vent. So maybe we just need to bite the bullet and get a proper unit installed. Has anyone had experience of doing this, particularly in a loft? Any things to watch out for/recommendations for installers, and would you be willing to say how much it cost (I'm seeing wildly varying prices quoted online)?

I know it's a lot of money for only a few days a year but as the summers are getting hotter it's becoming more of an issue every year. Any advice appreciated!

[Soizic]

We used a firm called Smile air con to do ours. Very simple and quick. Also there is another firm in Herne Hill we have used to service ours. Couldn’t live without it now

[HeadNun]

It's a good time to be in the AC business. Soizic, may I ask how many units you had fitted and roughly how much it cost? 

[Bob Buzzard]

I’ve got a full loft conversion - it’s massive.

[redjam]

14 hours ago, Soizic said:

We used a firm called Smile air con to do ours. Very simple and quick. Also there is another firm in Herne Hill we have used to service ours. Couldn’t live without it now

Thanks, Soizic. Was yours in a loft? How did they vent out the pipe for the hot air? And would you mind sharing (via PM if you prefer) how much it cost? I want to get a vague idea before deciding whether it's worth calling in a quote. Tbh at the moment I would consider selling my own children to pay for it.

[Peckhamgatecrasher]

I'm an air conditioning installer - this is everything you need to know about getting it fitted https://mol.im/a/14875047 via https://dailym.ai/android

 

This may be helpful (sorry it's the Daily Mail!)

[Sue]

On 04/07/2025 at 13:51, Peckhamgatecrasher said:

I'm an air conditioning installer - this is everything you need to know about getting it fitted https://mol.im/a/14875047 via https://dailym.ai/android

 

This may be helpful (sorry it's the Daily Mail!)

For one minute there I thought you were passing yourself off as an air conditioning installer, PGC 🤣

[Peckhamgatecrasher]

Put the Yorkshire on luv!

[Soizic]

Sorry on holiday so cannot send any photos or price , but think it was about 2,300 from memory. It does heating as well as it gets very cold in winter

[Sue]

On 05/07/2025 at 16:00, Peckhamgatecrasher said:

Put the Yorkshire on luv!

That has completely gone over my head!

[Peckhamgatecrasher]

That was my impression of an archetypal fitter requesting a strong cup of tea.

[green bean]

On 30/06/2025 at 17:41, redjam said:

OK so we are having our annual conversation about getting aircon fitted, as our west-facing loft turns into an ACTUAL FURNACE whenever the temperature goes over 25 degrees. (It's 33 degrees in here now and that's with the blackout blinds closed all day.)

We have Velux windows that are hinged in the middle so I think a portable unit is out of the question as it would be a nightmare with the vent. So maybe we just need to bite the bullet and get a proper unit installed. Has anyone had experience of doing this, particularly in a loft? Any things to watch out for/recommendations for installers, and would you be willing to say how much it cost (I'm seeing wildly varying prices quoted online)?

I know it's a lot of money for only a few days a year but as the summers are getting hotter it's becoming more of an issue every year. Any advice appreciated!

If you have velux windows, I’d highly recommend their external blinds - they are black mesh so allow light through but they stop the sun heating up the windows (which then act like radiators). On full sun days we shut all windows in the loft & use both external blinds and internal blackout blinds which significantly reduces the heat. We have shutters with internal thermal blackout blinds on the other window so use these too.

Velux also sell external metal shutters (not felt the need to stretch to these - much more expensive).

[penfold]

We had two air con units fitted with the heat pump mounted on the back wall.  one indoor unit in the loft and one in the kitchen/diner.  would not have been able to sleep in this heat in the loft without it - absolutely love it.  We have solar+batteries so with the amount of sun we having then its covering the cost of the aircon. 

we used Progas Heating Services Ltd,
176 Sydenham road,
London, SE26 5JZ
Tel: 020 8 676 0101
[email protected]

they were brilliant.  quick and straightforward to deal with.  highly recommend.  cost was ballpark £5k all in.  was quite a bit of chasing pipework into the walls and running pipes from the heat pump to the 2 units.

 

[redjam]

This is so helpful, everyone, thank you.

@green bean Yes we have just (as of yesterday) installed the same external blinds you mention! We already had blackout blinds and we now have the external awnings too. Of course that will guarantee the end of the summer sunshine but I can see that they're going to be helpful as they let the light through but not the glare of the sun - I'm fed up of working in darkness with both the blackout blinds closed on sunny days.

We'll see how we go with those for a bit but I reckon we'll get a couple of quotes from the other recommendations in case we end up going the whole hog. @penfold Love the idea of getting solar+batteries to offset the electricity usage so will look into that. 

Thanks, all.

[FellbriggSam]

On 19/07/2025 at 16:49, penfold said:

We had two air con units fitted with the heat pump mounted on the back wall.  one indoor unit in the loft and one in the kitchen/diner.  would not have been able to sleep in this heat in the loft without it - absolutely love it.  We have solar+batteries so with the amount of sun we having then its covering the cost of the aircon. 

we used Progas Heating Services Ltd,
176 Sydenham road,
London, SE26 5JZ
Tel: 020 8 676 0101
[email protected]

they were brilliant.  quick and straightforward to deal with.  highly recommend.  cost was ballpark £5k all in.  was quite a bit of chasing pipework into the walls and running pipes from the heat pump to the 2 units.

 

I installed an all-in-one air conditioning unit at my holiday home since I wasn’t allowed to have an external fan unit outside. It actually works just as well, was easier to fit, and although it’s slightly noisier, it’s a good solution overall.
https://www.orionairsales.co.uk/all-in-one-air-conditioning-142-c.asp?srsltid=AfmBOopZSVZj1_utAO-Hr4m5M323nRZru6Zmf1YuT4KP2touJ2OLaruU

[vladi]

Have you considered PIV - positive input ventilation. We retro fitted a Soler & Palau super quiet in-line fan system. This takes cool air from the outside ans is ducted into the loft. It is really quiet and very efficient.

It is controlled by a reverse thermostat ie one which shuts the system off when the temperature drops to a set level. We are very pleased with it especially as it costs a fraction of a/c and provides greater flexibility in terms of location of vents and ducting.