AIBU to keep the windows open?

[Lochroy]

It seems to be the new 'thing' that we should keep the windows on the sunny side of the house shut to prevent the external warmer air from entering the house.

I understand the logic.

However, with the windows shut, and even with blinds down, the glass act as like a green house and the inside ends up hotter than outside. So surely that's worse???

Plus there's a smidge of a breeze.

I'm not actually that bothered by the heat, I'm just trying to get my head around the argument.

We have a mix.

Cool rooms downstairs with shutters, foil blankets and shady side windows open. Doors closed to keep out any light or heat. This is where we'll sleep and we are preserving it at 23 degrees without a fan right now, despite 37 degrees outside in the shade.

Middle floor is shuttered, tilted shutters on a few small open windows let some warm air in, but minimal and mostly seems to be pulling the cooler air from the back. I think it's about 30 degrees.

Our roasting top floor is just abandoned, the windows are opened to try to at least have it stay similar to the outside temperature as it's usually several degrees hotter. We hope the heat isn't actually intense enough to creep downstairs. I would guess it's in the 40s, it's crazy. I'll go measure it at 4 when the temperature is at its hottest, just to see.

Well, this is the coolest Ive ever felt in a heat wave.

Yesterday we did have windows on the shady side open but as said I'm not risking that today.

Also I'm a huge fan of fresh air but coping at the moment!

What's everyone measuring temps with?

It’s not making a huge difference for me. Upstairs, the rooms on the sunny side are shut up, with the windows and curtains closed. Other rooms have the blinds closed and windows open. Downstairs the kitchen has everything shut and the hall and sitting room has everything open. I’ve a fan with ice water bottles in front of it in the sitting room for the hounds.

The rooms that are shut up are about the same temperature, but do feel stuffy and airless. The sitting room is 22° and quite pleasant. Kitchen is slightly cooler, but on the north side of the house. Upstairs is noticeably hotter, so we will sleep downstairs with the doors open

I think shutting up makes a lot of difference in hotter climates where it doesn’t cool off at night. But with British nights (except tonight, obvs) it’s really easy to lose heat at night and start again in the morning from a lower baseline. In Europe where they don’t have cool nights, the Heat just keeps accumulating day after day, so it’s more important not to let it in. We can usually take advantage of the short term gain from the breeze AND still lose heat overnight.

I have one window open, place is 23c
I don't know the outside temp but it felt like walking into an oven!

Windows and curtains were open all night but have been shut since 9.30am. Currently 37 degrees outside and 28 degrees in doors.

We won't open them until it's warmer inside than out.

Oh and we opened the loft hatch so any hot air can rise into the roof

Its 23 degrees in my house and 35 outside. All the windows and curtains were closed when the house and outside were about 21 degrees. We do have shading on the outside of the windows too which helps keep the sun off.

It’s not a new concept, the media have recently started with these PSA of common sense.

But with British nights (except tonight, obvs) it’s really easy to lose heat at night and start again in the morning from a lower baseline. In Europe where they don’t have cool nights, the Heat just keeps accumulating day after day, so it’s more important not to let it in.

But it's worth bearing in mind that parts of the UK, including London, is forecasting a minimum of 24 celsius overnight...

So the question for somebody who has managed to keep the inside of the house cool today is do they open up at all tonight and risk the internal temperature rising overnight? I don't have the answer, it's case by case and depends very much on the house and the weather forecastt.

Given the UK heat wave is supposed to be a very short one there might actually be an argument that some householders would be better off not "opening up" overnight.

Yes, its a dilemma. I think for us its say 23 overnight which is our current indoor temp so i might go with a fresh set of air.

I live in Spain and we keep the windows closed and shutters down on the windows the sun is shining on from late morning onwards. I air out the house at night and early morning as it does get stuffy keeping the windows closed for too long and although it's still warm at night, the temperature does drop to the low 20s. For a couple of days it's probably ok just to keep them closed, but if you have a cool breeze coming from the shady side I would try to air out the house or you won't be able to sleep at night.

I just tried opening a window in a room that doesn't have A/C. It's north facing so hasn't had the sun, and was OK heat wise anyway. I opened the window and a wall of heat came flooding through it, so I rapidly shut it again before I let any more in!

Hopefully DH has followed my instructions of shutting the curtains and windows on the sunny side of the house, but tomorrow's instruction may very well be keep them all shut, all day!

We have a single door on the north siding face of our house and normally that does pretty well at keeping much of the downstairs cool.

Looks like the temp has peaked here. Was up to 37 and now back at 36, so not quite the 40 they were predicting, thankfully.

I just hope my DCats have been able to find themselves somewhere cool enough for them. Will try wiping them down with a damp towel later, if I can find them and tempt them out from their hiding places!

We’ve experimented extensively over the last ten years 😂 and decided that in our house windows open upstairs and closed downstairs is the best way.

Everyone’s house is different.

I have heavy lined curtains in my living room and bedroom, and haven’t opened them at all today. The temp outside is 37, inside it is 27, which is significant. I spent some time outside as we have shady trees, good size paddling pool etc. Coming back in, the house felt really cool.

I won’t be opening any windows tonight as it won’t dip lower than 27 until gone midnight and I’d need to close them all around 5am before the heat builds again, so no point!

Gro-egg thermometer - stuck out of the window to test outside, plugged into each room inside to test. Outside measured 39, top floor 36.5, ground floor special room 25 (heat getting in since earlier with people roaming in and out, but fine for sleep under a fan), rest of the rooms in the middle.

I've had to be up early (5:30/6am) for the past few days. Throwing open every door and window before 7am really helps to cool the house down. Our house windows face SE and NW so obviously pay attention to when the sun gets round to your windows and keep an wye out for when the temp outdoors starts to climb.

Exactly!

It absolutely works here. My house is cooler inside than the air outside (by 10°C), so opening windows or doors just lets hot air in.

Blinds down and windows shut from about 8.30am. Earlier than that it was cooler outside than inside, so I had the front and back doors open to let a breeze through. Blinds still down to keep the sun out though!

Ok, well I'm happy to experiment tomorrow. Windows are all open tonight and I'll make sure they're shut by 9am in the morning, possibly earlier.