Internal shutters and curtains absolutely do a lot. The difference is most noticeable here in the kitchen, simply because I am more likely to forget to close the blinds there, but it is several degrees cooler after a day of sun intercepted by the blinds versus sun pouring directly into the room. The difference comes from the fact that visible light is reflected straight back out of the window (rather than bouncing around inside the room, heating up each surface it hits), and that a layer of hot air develops behind the blind - this hot air passes its heat slowly into the room, yes - but it also conducts into the outside. Because the air directly next to the window is significantly hotter than it would be with no barrier, it conducts outside much faster than it would be (because rate of heat transfer increases with the difference in heat). Meanwhile the heat transfer into the room is slower (because it’s instantaneous if you allow the sun in).
I hope we start putting external shutters on buildings faster. Everyone getting A/C is unsustainable, and as you say, it’s a lot for just a few weeks each year.
Absolutely - I’d love it if some of the energy efficiency grants would also go towards shutters (which can work for cold in the winter too). Not so useful for rooms you’re actually in, but great for keeping a room at home dark and cool whilst you’re at work.
Blinds are probably a lot better than curtains at this time of year as well. Most people (myself included) tend to leave rooms with “whatever they already had in them”, but it wouldn’t be a great hardship to swap curtains out for blinds for some of the year.
I disagree. Turning the lights on during the day for a few weeks every year isn’t a big problem! And I’d certainly rather do that than run A/C.
(As an aside, my desk is right in front of a window so I actually have to draw the curtains and have a light on a lot of the time anyway to be able to see my screen)
Internal shutters and curtains absolutely do a lot. The difference is most noticeable here in the kitchen, simply because I am more likely to forget to close the blinds there, but it is several degrees cooler after a day of sun intercepted by the blinds versus sun pouring directly into the room. The difference comes from the fact that visible light is reflected straight back out of the window (rather than bouncing around inside the room, heating up each surface it hits), and that a layer of hot air develops behind the blind - this hot air passes its heat slowly into the room, yes - but it also conducts into the outside. Because the air directly next to the window is significantly hotter than it would be with no barrier, it conducts outside much faster than it would be (because rate of heat transfer increases with the difference in heat). Meanwhile the heat transfer into the room is slower (because it’s instantaneous if you allow the sun in).
I hope we start putting external shutters on buildings faster. Everyone getting A/C is unsustainable, and as you say, it’s a lot for just a few weeks each year.
Absolutely - I’d love it if some of the energy efficiency grants would also go towards shutters (which can work for cold in the winter too). Not so useful for rooms you’re actually in, but great for keeping a room at home dark and cool whilst you’re at work.
Blinds are probably a lot better than curtains at this time of year as well. Most people (myself included) tend to leave rooms with “whatever they already had in them”, but it wouldn’t be a great hardship to swap curtains out for blinds for some of the year.
I disagree. Turning the lights on during the day for a few weeks every year isn’t a big problem! And I’d certainly rather do that than run A/C.
(As an aside, my desk is right in front of a window so I actually have to draw the curtains and have a light on a lot of the time anyway to be able to see my screen)