reflective screens to cover windows?

[agroot]

My cheap air-con is now running almost 24/7 since yesterday! Outside 34 and inside 25... need some creative way to reduce the heat further and save $$$.

Any suggestions? The heat appears to come from the two huge windows stretching to the long side of apartment - I have white fly screens installed on the outside and two layers of curtains inside (translucent + black-out), but not enough. Have anyone tried reflective screens on the outside, or something else? I have a long balcony but not glazed.

Also the bathroom is kind of hot, probably due to hot water pipes... can I cover them with heat-insulating materials?


EDIT: it just reached 40C outside! I'm glad I bought the ac in winter...

[SecretCode]

Anything inside the windows (curtains, blinds) is going to have only a limited time effect - the heat still gets in and just takes longer to dissipate through the flat.

Reflective sheets that you stick onto the outside of windows would help - but I believe are quite difficult to install, normally only used on office buildings - and of course you then have reduced light even in cold weather.

What do southern European countries do? They have shutters! Low tech, environmentally friendly wood, and very effective. I'm not at all sure about availability in Finland though, or whether your building would permit it.

[agroot]

Anything inside the windows (curtains, blinds) is going to have only a limited time effect - the heat still gets in and just takes longer to dissipate through the flat.

Reflective sheets that you stick onto the outside of windows would help - but I believe are quite difficult to install, normally only used on office buildings - and of course you then have reduced light even in cold weather.

What do southern European countries do? They have shutters! Low tech, environmentally friendly wood, and very effective. I'm not at all sure about availability in Finland though, or whether your building would permit it.

All right I installed the reflective film first outside of the window. It sticks to the glass by static electricity so installation isn't too difficult once I figured out the whole process. Outside is ugly as hell since I did it in a hurry and it's full of bubbles and some windows need several films combined, but from the inside it looks fine, just like raining on glass. Not sure how it will last winter, but I'd do anything just to survive this summer myself. (I forgot how I survived the first 2 years - aircon has lowered my heat tolerance significantly it seems)

How does shutters help? Are they heat insulated?

[SecretCode]

If the film comes off easily, that sounds like a good plan.

Shutters just keep the sun's rays out so there's practically no heating from that source. None of this is going to stop the flat heating up through the walls and ceiling and floor when the outdoor temperature is high for more than a week!

[Upphew]

How does shutters help? Are they heat insulated?

Shutters aren't insulated, but they block sun's rays really well. And then those rays won't go through the transparent window and heat non transparent stuff behind. Which is bad as the window is insulated and will keep the heat in. With shutters they would keep the heat out.

[agroot]

Shutters aren't insulated, but they block sun's rays really well. And then those rays won't go through the transparent window and heat non transparent stuff behind. Which is bad as the window is insulated and will keep the heat in. With shutters they would keep the heat out.

But Finnish apartment windows cannot even be fully opened - I can only get sufficient cooling by opening both doors.


I got another idea! Since there is a balcony right outside of windows, why not install outdoor curtains? that can be taken off in winter and washed - just need to figure out how to glue the curtain rails to ceiling.

Or something like outdoor partition/divider but reflective on the outside?

If the film comes off easily, that sounds like a good plan.

It can, but now it looks really horrible from outside because manufacturer put glue on that side (it's supposed to stick by static not glue), so some parts have been folded by accident and needed to be separated by force, leaving lots of wrinkles

[SecretCode]

Thinking about it, shutters work best with inward-opening windows or sash windows (that slide up and down).

But since you've got a balcony, putting shutters on the outside and going onto the balcony to open and close them would be easy!

I got another idea! Since there is a balcony right outside of windows, why not install outdoor curtains? that can be taken off in winter and washed - just need to figure out how to glue the curtain rails to ceiling.

Or something like outdoor partition/divider but reflective on the outside?

An outdoor curtain would need to be very strong, and tied down at the bottom as well as the top, for winds.

An outdoor partition, however, is pretty much exactly what a shutter is! Let's see if I can find some images of shutters ...

[Upphew]

But Finnish apartment windows cannot even be fully opened - I can only get sufficient cooling by opening both doors.

Shutters keep the heat out, but if you push air through them to inside, you warm up the blinds and with them the air coming through.

I got another idea! Since there is a balcony right outside of windows, why not install outdoor curtains? that can be taken off in winter and washed - just need to figure out how to glue the curtain rails to ceiling.

That is the way to go. Stop the infrared radiation as far as possible. I'd likely use blinds rather than curtains. Although curtains might be easier to wash or cheaper to replace.

[Ulminpoika]

Back in my old apartment in Munich we had the oldest windows in town and direct sunlight shining on them. The place would heat up to 30°C in summer. Our solution was to attach newspaper (on the outside!) of the windows, with that painter's tape that can easily be removed. After all this heat wave will be over in a while and I would not spend to much on something that will annoy you for the rest of the year.

A friend has done that on the inside of a window and the heat that accumulated in the window actually broke the glass, so don't do that.

[NukkuMatti]

Almost all Finish houses have triple glass with the outside glass having about 3-4 cm space to the inside 2 glasses (or single thermopane vacuum/low air density double glass).

So for a more esthetic view you might want to opt for this solution:

There are blinds for sale that fit in between this 3-4 cm space (take white ones, not dark ones) for example:
https://www.k-rauta.fi/tuote/salekaihdi ... 4106801014

And they can be operated by the control wires going through the inside window frame (need to drill small holes for that). I have had them myself in my previous homes, had to leave some of them mounted in the last, because otherwise the housing company would charge me for repairing the window frames.... (removed half of them and reused them in my new apartment and plugged all holes with same color filler ). Special bendable tubes and connection rods are available a K-rauta for operating the blinds and feed through the wires.

https://www.k-rauta.fi/tuote/kaihtimien ... 4675149317 .... this one goes through the top hole of this one:
https://www.k-rauta.fi/tuote/naruohjain ... 4676001065

You got to connect the "säätotanko" to the end of the turning iron spoke inside of the blinds,that make the blinds open and close horizontally, the wires for pulling up the blinds, goes through the flexible tube, readjusting the blinds is needed to have it work, but if you are a bit handy yourself, you can do it... I converted standard blinds into these in between blinds quite often myself... but there is a reason my friends call me MacGyver..

2 benefits: there will come virtually no dust on the blinds for a long time so cleaning is rarely needed, and it keeps the heat outside the inner double glass window, therefore only heating up the space between the ventilated outside window and frame and the double glazed insulated inside frame.. Never had any problems with that and it worked quite well to keep the inside glass cool as well.
In winter you just pull them up and the small winter sun can still heat up your cold home a little...

just an idea...

[Upphew]

2 benefits: there will come virtually no dust on the blinds for a long time so cleaning is rarely needed, and it keeps the heat outside the inner double glass window, therefore only heating up the space between the ventilated outside window and frame and the double glazed insulated inside frame.. Never had any problems with that and it worked quite well to keep the inside glass cool as well.
In winter you just pull them up and the small winter sun can still heat up your cold home a little...

I won't agree with the no dust part. Unless you live in place with no dust. Either dust from street or pollen will make them dusty. And cleaning them is _pain_. I dread the day I need to move out from my current apartment and the 5+ years of dust need to be dealt with...

[agroot]

I think some sort of active cooling is going to be needed.. was 26C outside last night after dark and I could barely keep the room at 28C. While it was a mistake to buy a less powerful aircon, electricity fee is not saved either way and there was no sunlight to block.

But what can I do? I noticed that:

1. The main heat source is the exposed hot water pipes from bathroom - it's always hotter than the rest
2. Tap water is still cool even when it's 40C outside at day

So... water cooling whole apartment anyone?

[NukkuMatti]

2 benefits: there will come virtually no dust on the blinds for a long time so cleaning is rarely needed, and it keeps the heat outside the inner double glass window, therefore only heating up the space between the ventilated outside window and frame and the double glazed insulated inside frame.. Never had any problems with that and it worked quite well to keep the inside glass cool as well.
In winter you just pull them up and the small winter sun can still heat up your cold home a little...

I won't agree with the no dust part. Unless you live in place with no dust. Either dust from street or pollen will make them dusty. And cleaning them is _pain_. I dread the day I need to move out from my current apartment and the 5+ years of dust need to be dealt with...

How would the dust get there? That means the insulation of the outside window to the space between the outside window and inside windows, is leaking too much air, if the construction is supposed to ventilate (depending on the brand and system used) one should place pollen filters in the vents.. problem solved, I have never ever needed to clean them (or maybe I just moved away to another building before that time ...grin..)

Regarding the heat pipes of OP.s bathroom, there are round preformed insulation foam tubes for sale that go around the pipes to prevent heat loss of the hot water pipes to the surrounding air, might make a difference to use those in the bathroom. Make sure to paint them after mounting (or before) on the outside, to prevent they will act as a sponge and lose their insulating efficiency.

[Upphew]

2 benefits: there will come virtually no dust on the blinds for a long time so cleaning is rarely needed, and it keeps the heat outside the inner double glass window, therefore only heating up the space between the ventilated outside window and frame and the double glazed insulated inside frame.. Never had any problems with that and it worked quite well to keep the inside glass cool as well.
In winter you just pull them up and the small winter sun can still heat up your cold home a little...

I won't agree with the no dust part. Unless you live in place with no dust. Either dust from street or pollen will make them dusty. And cleaning them is _pain_. I dread the day I need to move out from my current apartment and the 5+ years of dust need to be dealt with...

How would the dust get there? That means the insulation of the outside window to the space between the outside window and inside windows, is leaking too much air, if the construction is supposed to ventilate (depending on the brand and system used) one should place pollen filters in the vents.. problem solved, I have never ever needed to clean them (or maybe I just moved away to another building before that time ...grin..)

Outer pane isn't airtight. Windows with vents can circulate the air between inner and outer pane to warm it.

[rhodri]

We hung one of those emergency mylar blankets from a first aid kit over our big window with sticky tape and it worked wonders. Gave one to our neighbours and they did the same. Has made a huge difference to the temperature inside the apartment. They do let a small amount of light in which is nice. They are cheap and easy to put up.