Seeking sunblock for windows

June 23, 2022 10:28 AM

I have installed external shutters on most of the windows on the southeast side of my house, with the goal of blocking out as much sun as possie during summer heatwaves. There is one window (about 65 x 140cm) that still lacks sun protection, so the sun & heat still get in through there. What easy, cheap, and above all effective solutions will keep out most of this sunlight? (Definitions for all three adjectives below the fold.)

Cheap = under €100, ideally
Easy = no actual drilling or material alterations needed
Effective = keeps out most of the sun, but doesn't have to block it entirely

I suggested to my husband that we just put up aluminium foil on the window in question; he opposed it on the basis that it would annoy the neighbours (probably true). I saw something about bubble wrap; would this work? Or just putting up an easy-to-install roller blind? Have you tried any quick DIY hacks that successfully kept the sun out of your home? If you have any specific product recs, that would be amazing.

I live in the Netherlands, so ideally any proposed solution would be available here.

posted by littlegreen to Home & Garden (13 answers total)

We have one window like that, and I ended up taping pieces of foamboard into a piece that fit inside the window. It's white and so unobjectionable to anyone outside, and a tiny bit insulated, and reflective so it helped with the heat from the window.

You might also find paper blinds at your local hardware/diy store. I believe they just use an adhesive strip similar to Command adhesive.
posted by Lyn Never at 10:42 AM on June 23, 2022 [3 favorites]

I would not advise foil, it is reflective but it also doesn't breathe and you can end up with a lot of trapped water vapor and mold. But along that line there are reflective films you can apply directly to the glass that will block some of the light but also a lot of the heat and UV. (Not necessarily all of the infrared.) They're tricky to put on, especially for larger windows because it's easy to get bubbles. But they'll also still allow you to look out the window (though it does look like a smoky gray filter). You could probably do that for less than €40. The neighbors would see a reflective surface, but more mirror-like than silver.

Have you looked at tension rods? You can get some very inexpensive lined curtains, which usually have a white liner which reflects heat very well and the double layer also insulates. It allows you to take it down during the cooler months.

A roller blind on a tension rod is also an excellent solution.

The Command line from 3M has removable hooks, that you could also hang a roller blind or other curtain rod from without putting holes in anything .
posted by typetive at 10:58 AM on June 23, 2022

Not sure how available these are in the Netherlands, but with your requirement for no alterations, your best options are probably: window film (doesn't block as much as aluminum foil, but it's better than nothing, and less ugly for your neighbors) and blinds mounted with adhesive.
posted by caek at 11:01 AM on June 23, 2022 [1 favorite]

3 options:

1. If your windows have the space for it, telescopic curtain rods that you can hang a thick enough fabric for curtain material. Blackout curtains might be expensive and heavy where you are, but search for variations of japanese cafe curtains + rod. (On preview: yes these are also known as tension rods)

1a. Adhesive-based brackets to hang those rods if there's no bit of recessed space to attach those rods otherwise.

1c. Flexible curtain tracks that are applied with adhesive especially if the distance to the ceiling isn't too high so you're basically doing a window treatment.

2. Magnetic window screens - one side of the magnetic strip does use adhesive though.

3. Yup, window tinting film.
posted by cendawanita at 11:01 AM on June 23, 2022

I have a new streetlight outside my bedroom that's as bright as a parked UFO. I got some of this fabric (sorry, it's from Amazon). It is very light, such that you could put it up with just a strip of painter's tape. The silver side is a matte silver, so it's unlikely to bother the neighbors. It blocks 100% of the light as far as I can tell (of course, there will be leakage around the edges unless you fasten it all around).
posted by bricoleur at 11:48 AM on June 23, 2022 [3 favorites]

IIRC the Netherlands should have normal windows that open in a civilised non-sliding manner - mini-blinds that you slide over the top of the window pane should do nicely. Or in a pinch, craft paper taped to the window.
posted by I claim sanctuary at 11:50 AM on June 23, 2022

I just taped (masking tape) white paper to the inside of the windows. I suggest this as a stop-gap measure while you figure out something you like better in terms of effectiveness and aesthetics!
posted by spamandkimchi at 1:25 PM on June 23, 2022

Very similar to spamandkimchi, I've used brown butcher paper with painter's tape applied directly to the metal window frame. It is very inexpensive and very effective! And you can totally reuse the paper year to year if you have a place to roll it or fold it up and store it. I found that two rooms were the primary heat culprits, so I just covered windows and /or sliding glass doors in these rooms.
posted by happy_cat at 1:58 PM on June 23, 2022 [1 favorite]

We put up paper blinds when we needed to turn an office into a spare bedroom. Super cheap, taped up in a minute, and looks very proper if you don't get too close. Highly recommend. We bought our at a local big hardware store, but these online look slightly nicer.
posted by advicepig at 2:05 PM on June 23, 2022

I have a mylar blanket taped loosely over my bedroom windows. It keeps out enough heat that I haven't had to put in the window AC unit as of yet - I have had to put in the one in my living room, because if I put up a mylar blanket in there the lack of light will kill my ficus.
posted by bile and syntax at 2:13 PM on June 23, 2022

Posting on behalf of a friend, who says:

https://www.3mnederland.nl/3M/nl_NL/p/d/b00016721/

We used the Prestige 70 exterior window film at the cottage and it made a big difference without darkening the windows too much. It's not going to be under 100 euros to have someone install it but two of out of three of their criteria isn't bad
posted by tiamat at 3:00 PM on June 23, 2022

On the off-chance that you own ground below the window, annual vines on lightweight string trellises are wonderful seasonal shade. Evapotranspirative cooling, dappled shade, flowers, hummingbirds.

(Window boxes also make this possible but require drilling, so not this window now.)
posted by clew at 6:21 PM on June 23, 2022 [1 favorite]

I have IKEA schottis black out blinds for this. They are really cheap, thick treated papery blinds, easily cut with scissors and stick directly to the glass if need be so no damage or drilling etc. You can clip them up out of the way and they are fairly unobtrusive. They work amazingly well for me.
posted by ElasticParrot at 5:18 AM on June 24, 2022