[Closed] Changes to the house to make it cooler

With sweltering hot spells seemingly more common,

It was nearly 23 degrees on the one day last week when it didn't piss down.

Loft has a decent amount of insulation, 300mm in some, 150mm where I have it boarded for storage

That's not very much. We had 300mm, and then I added another 300mm or so before putting in a suspended floor above that. Made a big difference in winter even though the house was previously pretty warm. However I'm not sure it does much in summer because there can be a huge heat differential between the loft and house even with the door open.

You could try taping or hanging pieces of foil-backed insulation that block all light to the windows. You might also want to look at ceiling fans - won't keep the temps any lower but a bit of air movement does wonders.

Do you have a fire place and or wood burner? If so is it blocked / doors closed? Open it up to create a draft

leave you loft hatch open during the night to let heat out ?
works in our bungalow

I had ridge vents in my last house (build circa 1985) and found that opening the loft hatch would increase airflow through the house as the warmer air would flow up and out, like a chimney. You could try this.

Also, given the age of your property, do you have open fireplaces? If so, make sure the throat plates are open, this may well help (probably).

Edit

Beaten to it by Sofaking

House is 1930s brick built, solid walls (no cavity), rendered and painted white (thankfully! I nearly changed it to trendy grey, very glad I didn’t now). Loft has a decent amount of insulation, 300mm in some, 150mm where I have it boarded for storage. Tiled, unfelted.

Snap! I think you've done a lot of sensible stuff... unfortunately your solid walls are quite effective at retaining heat overnight, as you're finding out. You're looking at about £1500 for internal shutters on a large bay, not sure about external. If the back of your house is southerly you could think about a brise soleil or pergola across the back of the house, which would keep the sun off the ground floor. You could top up all of your loft to 300mm by fitting new timbers at right angles to the existing, and then topping up with insulation to their depth. Fix the boards over the top and don't bury any wiring underneath the insulation.

2 wood burners, heat the house almost exclusively with them all winter (gas Ch used by the wife if I'm out of an evening, that's it). Fairly sure I left the site vents open on the stoves, I'll go and check.

In the 2 bedrooms one fireplace is blocked off, one is open. The closed one is the hottest room but that's the front of the house with a South facing bay window. I ought to put an air vent in it though, the fireplace that is.

Also, if you have a hot water tank make sure it's mega insulated. We have one on the top floor where it's hottest - I super-lagged the pipes in the airing cupboard and draped a duvet over it (even though it's already insulated) which has made a big difference in the warmth coming from it.

One more thing - at night our downstairs is cooler of course so we have a big powerful fan (the one I use for Zwifting) blowing up the stairs - with our bedroom doors open it creates just enough air movement to be beneficial.

£250 on aircon will be far more effective

With sweltering hot spells seemingly more common, how do I update the house to make it cooler?

I don’t want air con. I’m after sensible changes to make.

It is ridiculously hot for 2 weeks max a year. Just get a portable air con unit as it will only be turned on for a small period of time and then store it out of sight the rest of the time. At least it will work, unlike fans...

You'd be looking at a lot more than £250 for a decent air con (with external condenser), more like £1.5-2k fitted + the running costs (although this is what I'm going to do as I don't think anything else is going to make enough of a difference even if it's a cheaper option)

Ceiling fans make a huge difference at night, and they're IME a lot quieter than free-standing models. You can also reverse them which is supposed to help with heating a room, although I can't say I've ever bothered.

leave you loft hatch open during the night to let heat out ?

+1

Creates quite a through flow of air. Its pretty ventilated up there but luckily we also have a velux in the loft so if that is open too the air rushes out.

Couple of nice guitars strategically placed in the lounge works for us.

Fairly sure I left the site vents open on the stoves, I’ll go and check.

I mean fully open the door. Don't restrict that air flow though small vents. Re the blocked fire place you could try some sort of door or system that allows you to block in winter and open fully in summer.

One stove was shut, now open.
Combi boiler so no tank.
This is London perchy, it's way warmer than 23C. .... Right now I crave 23C! You lucky sod!

Yep doing the fan thing, I set it at the open beck door and you can feel the flow of cold air at the top of the stairs so it must push a lot of hot air out the windows that are open up there in the evening.

Open loft hatch? Hmm. Hadn't tried that...I know it's sweltering up there in the day and evening, I don't know if it cools much over night or not. I would consider adding vent tiles or such like though.

Yes ransos, Indeed! We need external wall insulation solutions that arent so costly. I reckon payback on winter heading bills, based on when I heated with gas, would be 15-20 years. Ok it would also make for better comfort, but I'm looking for the cheaper and easier improvements first. Particularly as I hope to move in a few years.

Hmmm I'm thinking foil insulation like used inside car windscreens, suckered on to the windows outside. It would look a sight, but cheap and easy enough to put up and take down maybe.

It was nearly 23 degrees on the one day last week when it didn’t piss down.

think it's about 21 now, but it did rain this morning...

Open loft hatch? Hmm. Hadn’t tried that…I know it’s sweltering up there in the day and evening, I don’t know if it cools much over night or not. I would consider adding vent tiles or such like though.

cools down very quickly as roof tiles arent very insulating. and there should be lots of airflow up there too

You’d be looking at a lot more than £250 for a decent air con (with external condenser), more like £1.5-2k fitted + the running costs

Couple of nice guitars strategically placed in the lounge works for us

Respecting the work there. 👍🏼
Is pampas grass still a thing?

Of course i'm not referring to a plumbed in split system for £250!

a stand alone unit moved around the house to where you are spending the time provides an ample solution for a couple of days a year

Are there better ways of doing it ? yes.

We have all been on holiday, everywhere is fitted with a split system and a brise soleil if not roller shutters, depends on your budget, by the sounds of it a 20" fan and opening windows means quite a low number.

21C, now you're really taking the p***. That's been the overnight low for the last 3-4 nights.

Opening loft hatch makes a massive difference at our place, especially since the cavity wall insulation and extra loft insulation was fitted ~10 years ago.

Ceiling fans can make a huge difference. I used to live in Houston and most nights I could sleep without a/c if I had the ceiling fan on.

I agree with the venting via loft hatch and ridge vents.

Loft has a decent amount of insulation, 300mm in some, 150mm where I have it boarded for storage

Lightweight Insulation is rubbish at keeping you cool.
As is the solid wall of only one brick. Look up 'decrement delay' - basically how long it takes for heat to transmit in or out a house. A long day of belting sunshine is far more energy than a winter night of heating.

Reflective layer would stop heat getting into the roof space quite well - just make sure the heat it reflects back can chimney out the ridge. Same with windows, a reflective and opaque surface outside of the window will work well.

Other than that, knock the house down and start again... 🤪

Sprinkler wetting down outside walls and patio takes heat out of the structure quite rapidly. You'll be amazed how quickly a wet wall drys though.

It is ridiculously hot for 2 weeks max a year

Depends what you consider ridiculous, I get hot at about 22, when the house is 26 overnight (second prolonged spell of that already this year) I don't really sleep even doing what I can to keep the place cool, I will try the loft hatch tonight though.

Sprinkler wetting down outside walls and patio takes heat out of the structure quite rapidly. You’ll be amazed how quickly a wet wall drys though.

Hmmmm, This a leaving the loft hatch open might be worth a try for us tonight...

Currently 29C in the coolest back bedroom, front bedroom must be 32+. I'll likely get it down 1-2C over night.

Thank you Moab. I think I'll look at making some window shades to stick on the outside in the future hot spells

When I win the lottery I'll have external insulation fitted, triple glazing and external blinds. And a Velux window in the loft with remote control.

Solar control film on windows on the sunny side. Correct product and good fitting should give a few degrees of benefit. I’m not just talking tinted, proper reflective solar control.
Like
https://www.windowfilm.co.uk/buy-online/window-film-by-the-metre/solar-control

Indeed Murray. Next house I might!

Ooo, I'll take a look at that film, thank you. I think I need to make the walls reflective too, ha ha!

Ceiling fans make a huge difference at night

One of the best things I ever bought. Quiet it is not when at full lick, but it's pretty old and well overdue me balancing it.

are ceiling fans easy to instal? any extra wiring needed? any recommendations?

Eddiebaby, on the Pampas it is.

I just remembered a relatively easy mod you could do. We have three floors so the upstairs is always hot. You can get in-line extractor fans that have a pipe in and out, it would be pretty easy to fit one of those with vents in the ceiling of your rooms to suck out hot air. And these days you could easily make it remote controlled using home automation plugs.

1930s house in SW france:

Shutters, the latted type that let light in ( and have netting to keep the insects out). No solar gain in the day and ventilation without a security risk at night. In winter a board covers the latts to provide more insulation.

More than twice as much insulation as you have in the roof.

Insulated walls

Triple glazed windows.

We cook outside

The temperature gradually creeps up during a heat wave but so far this year we haven't seen more than 28°C inside even though it's been up to 40°C outside. We haven't got A/C - edit: or fans either.

are ceiling fans easy to instal?

I managed to install a simple one from B&Q a couple of years ago and my house hasn't burnt down yet, so I'd say yes. 😀

are ceiling fans easy to instal? any extra wiring needed? any recommendations?

I have this, only in a 5-blade flavour:

https://www.argos.co.uk/product/4306528

Piece of piss to fit, you screw the baseplate to the ceiling and the rest of the assembly to that.

Wiring wise there might be issues with the additional load across wiring intended for a couple of bulbs but I thought "bugger it" and my Victorian wiring has so far failed to burn down the house in like 20 years of use despite at one point having the bath burst directly above and gallons of water flowing through the fitting.

The cord to toggle the lights snapped years ago but I just took the hit that if the fan was on then the lights had to be too, until fixing that problem a couple of years back with a job lot of Philips Hue.

Ceiling fans run off the light circuit I expect. My upstairs ceiling height isn't so much, 7'9" I think, so fan might not fit but I had considered them briefly, I know fans help.

Flip me, outside is still 28C... Trying to cool the house with hot air is a wee problem.

Forecast too still be 25C at midnight.

thanks gents, ill look into it i think. although by the time i get round to fitting one i bet itll be arctic conditions again....

My upstairs ceiling height isn’t so much, 7’9″ I think,

The minimum ceiling height for mine was 2.3m which is about 7'6" so you're probably OK (depending on fan choice I suppose).

Mine came with a long- and a short-drop suspending pole, I used the longer one because the ceiling of this 1890s terrace is in the lower troposphere.

As educator says in hotter climates people tend to shut the heat out so you don’t get the solar gain in the day and the fabric of the interior  house acting like a thermal store and releasing that heat again at night. Try to stop the heat getting in rather than work to get it out - that might be as simple as closing the curtains during the day but shutters or canopies on the outside would be more effective

Uk housing stock is a bit weird - we seem to have to wrong size windows for our latitude - too big for both the heat in the summer and the cold in the winter. The bog standard 70s house I grew up in has one whole wall in each ground floor room as glass - floor to ceiling edge to edge. It originally had a porch at the front that was glazed Floor to ceiling on all three sides too but we had to replace it with a brick built one because our front door handle was too hot to touch. Pretty crazy way to spec houses in either a UK summer or a UK winter really.

jeez even the frogs are too hot! I just got joined by a very large one in the lounge! got him in a box after a bit of a chase and shifting the sofa. He must have been looking for somewhere cooler than the garden, hopped up 23 steps, in the conservatory through the open door, into the kitchen, out into the hall, straight down and into the lounge. I caught the movement out the corner of my eye and for a moment thought, f***, another mouse....but then nooo...its way too big and its...well...frog shaped, bl00dy hell! wife shrieks and then starts videoing me chasing it round the house!

and yes I try and do the 'shut the heat out' and then ventilate in the evening. I find it works very well but if the hot is intense like this, for over 3 days, well the house eventually levels out with outside. external shutters and external wall insulation would probably help massively, but although I think it is very wrong from a green point of view, a decent air conditioning system would be a fraction of the cost of that lot, quite possibly not more than just shutters. Daft.

UK housing stock is old, and of a generally poor standard, and not designed with this heat in mind at all.

Sitting in bed with our cold water bottles from the freezer.

You can get in-line extractor fans that have a pipe in and out,

I've been to some pretty hot places and in the absence of A/C that's pretty common. Whole house fans is one name. Either a big fan in a central spot on the ceiling of the uppermost floor, or a small powerful one in the loft with ducts to all the rooms on the upper floor. Leave upper windows closed and lower ones open, so you don't short circuit the stack effect.

You might be better putting the fan upstairs blowing out rather than downstairs blowing in, if you have downstairs windows open.

Solid walls give good thermal mass which helps the interior temperature maintain a flatter cure over the day/night cycle. Thermal mass is good.

Trying to eliminate some of the solar-gain through windows is your best bet IMHO. Preventing the sun hitting the glass is far better than blocking it once it's already in the room (i.e by using internal blinds or curtains).

UK housing stock is old, and of a generally poor standard, and not designed with this heat in mind at all.

I can only speak anecdotally but the 00's flat I used to live in was utter murder during hot summer days. I think the solar gain was to blame having windows on three sides. The insulated cavity walls and floor and ceiling insulation afforded little thermal mass so there was no dampening effect to offset.

My 1850's terrace performs far better in the summer IMHO although it's cold as **** in winter.

I have a 2.5kw Toshiba split ac unit in my bedroom. Cost me £900 including fitting. I’m as careful with bills as you can be but set at 21 degrees and running all night I hardly notice the cost.

Insulate as much as possible it works to keep the heat out too, white or reflective blinds they do make a difference, interior / exterior thermometer so when it's hotter outside close your doors and windows!

28c at 7am this morning in my living room (where I'm currently WFH home), it's going to be a fun day 🙁

I managed to install a simple one from B&Q a couple of years ago and my house hasn’t burnt down yet, so I’d say yes

Likewise 🙂

Our front door which has a window used to be the weak point so I made up a cover out of a doubled old sheet. You could make one for any window.

Our house gets too hot in the summer (in Manchester of all places) - two bedrooms are south facing and get the sun all day - curtains shut, but with the house being well insulated, the southern wall is like a heat sink. Downstairs is OK as only the kitchen window is south facing, and the lounge doesn't get direct sun. We've has a portable AC for at least 15 years.

It's loud, but you get used to the noise and we probably run it for 4 weeks during the summer, like now when it's over 20c. We have it upstairs with the exhaust pipe going out of the bathroom window. Touch wood, it's been incredibly reliable. Only ever had problems once and that was caused by build up of dust (had to strip the casing down to get at it).

Educator, what's the wall construction on houses Like yours in France? I'm guessing possibly thicker then here in UK, but around as that is just a guess.

Victorian house. Working from upstairs SW facing room with windows and doors open for slight breeze through the house (upstairs has better airflow). Blinds down once the sun passes but it was 34C outside and nearer 40C inside yesterday. I don't mind the heat to be honest.

I freeze small thermos flasks with 1/4 water then drink iced water all day. Then go for a swim with the dog in the Thames!

We also have a small AC unit in the loft room. It's 900W and used sparingly.

Well I briefly got it down to 28C in the girls bedroom last night, before the wife had a shower, shutting the bathroom window and like most women, having it far hotter than i could bear. Despite the bathroom fan that pushed the bedroom temp back up to 29.5 and it's taken until this morning to get it back down. Outside temps hit 29C an hour ago so windows are shut again now, I'm working in a different room with the fan blowing at me and currently feel comfortable, but it's 2-7pm ish that is the hottest here. Hoping the rain arrives and cools us properly!

Just sprayed the path and flower bed outside my home office window. Temperature is now down to 30.5 in the office...

This is with all the leaving windows open at night, using curtains to keep the heat out during the day (with windows open when in direct sunlight to allow the hot air to escape).

Mid 60s timber framed house with a brick skin, so f all thermal mass or insulation and external insulation only possibility to improve due to timber frame.

Does anyone have any real world experience of external skylight blinds.

One website stated the difference between internal and external blinds as being 37% heat transmission Vs 4-14%. They are trying to sell window blinds though so pinch of salt and all.

It seems obvious that stoping the heat on the outside of the house would be better than once it's already inside but how much better really?

It seems obvious that stoping the heat on the outside of the house would be better than once it’s already inside but how much better really?

Yes it's significant.

This is why a lot of commercial buildings have brise soleils and vertical fins now. Years ago they would just rely on blinds to keep the sun out in summer.

Ideally, you want a set-up which allows the exclusion of the sun during summer but takes advantage of solar gain in winter. This could even be a deciduous tree for example which gives the window/house shade in summer but when all the leaves fall off in winter the sun can provide solar gain.

Ideally, you want a set-up which allows the exclusion of the sun during summer but takes advantage of solar gain in winter. This could even be a deciduous tree for example which gives the window/house shade in summer but when all the leaves fall off in winter the sun can provide solar gain.

Yeah this is why reflective coatings aren't something I'm looking at.

I think I need to setup some data logging thermometers and then try covering the outside of the window and compare.

Educator, what’s the wall construction on houses Like yours in France? I’m guessing possibly thicker then here in UK, but around as that is just a guess.

I've seen houses being built in Southern France, they seem to favour hollow terracotta blocks which I think are designed to let the hot air rise through the bricks instead of transmitting. The roof tiles are similar I think, and of course they are whitewashed.

Plant a grape vine on the south facing wall. They can be very big plants and could be trained on a series of wires to give shade to the wall. Before the winter, prune it back to get maximum solar gain back onto the wall.
Added benefit is they look attractive and provide you/the birds with grapes or even wine!

Those walls are blocks lined with thin hollow bricks, no better than a UK cavity wall at R=.6 or thereabouts. I've added R=3.2 insulation to the inside so the wall is now about R=4.

The temperature indoors dropped from 28°C to 26°C overnight with a dawn minimum outside of 24°C. We shut up when we went out and have just got back to find 27°C indoors. It wasn't as hot out today, low 30s. If we time the opening up and shutting up right we can usually keep the indoor temperature to within 5° of the outside dawn minimum.

Closing curtains makes little or no difference, the important thing is to keep the sun off the glass. Once the sun's rays get through the glass the green house effect means the heat stays in.

Closing curtains makes little or no difference

Disagree with this - makes a big difference in our house, but they are thick and dark curtains with blackout fabric.

Plant a grape vine on the south facing wall. They can be very big plants and could be trained on a series of wires to give shade to the wall. Before the winter, prune it back to get maximum solar gain back onto the wall.

Or just go for Virginia Creeper which is deciduous and trains itself to the wall.