My room has the following window:

enter image description here

My room becomes extremely warm whenever the day is sunny (the window is facing the south) and the outside temperature is a bit warn (> 60F/15C). Yesterday for example, my room temperature was over 88F/31C most of the day, despite opening the windows at night and the outside temperature being 70F/21C. Even when outside temperature get colder (I live in Massachusetts and temperatures may vary a lot from day to day, or even within the same day), it takes many hours for my room temperature to get lower.

Opening the windows during the day don't help, because the window opening is tiny and as you can see in the picture it opens to the bottom (which means the cold air from outside cannot enter the warm room, since cold air goes down and warm air goes up).).

Is there anything that can be done to make the room temperature lower?

My 5 ideas so far:

  1. Turning on the air conditioning: this isn't possible (quote from the building house manager where I rent the room: "We are still a couple weeks away from the building wide turnover. It has to be a complete Heat to AC Switch in our building (Heat turned off, Chillers turned on), so we have to wait until risk of cold days/nights are behind us."). I also cannot cut the window to install an AC.
  2. Placing some "air pump" on the window, i.e. some pipe measuring one or two meter that would go from outside to inside through the window. Does such things exist? The only items I could found so far were window air conditioner, e.g.:

    enter image description here

    However, since the outside air is not that warm I don't need to isolate the window: a simple pipe flushing some air from outside to inside would be enough (the pipe doesn't need to cool the air).

  3. Adding more curtains, as it shown below: it helps a bit but not that much.

    enter image description here

  4. Placing some heat control window films to the window. I haven't tried it yet, I don't know to what extent it would reduce the heat. Should I expect some significant improvement with it?

  5. Adding some external window shutter. I'm not allowed to do so:

    enter image description here

  • 2
    Given that you're not allowed to modify anything, VTC as off-topic. The solution is to run a fan though.
    – mmathis
    Apr 19, 2017 at 15:50
  • @mmathis I am allowed to modified some things, e.g. placing films on the window. Apr 19, 2017 at 15:56
  • @mmathis disagree. He has options within the realm of home improvement. For instance there are A/C units specifically designed for this situation, I used one in a server room in a leased building where it was not possible to install sufficient A/C. Apr 19, 2017 at 16:22
  • @Harper fair enough, flag retracted
    – mmathis
    Apr 19, 2017 at 16:31
  • 1
    One of these: doityourselfrv.com/diy-air-conditioner
    – CactusCake
    Apr 19, 2017 at 20:07

5 Answers 5


How about getting a Portable Air Conditioner - these can be moved room to room as long as you have a window you can feed the exhaust out. The link I provide in the example below shows two types of A/C units make sure you get the Portable Unit and NOT a window unit - they are different animals altogether.

Or you could buy a fan and place in front of that window.

Example of Portable Air Conditioner (more examples on Amazon):

enter image description here


As said above a portable AC is a great option. There are shrouds specifically for your type of windows on Amazon. However, two things to keep in mind are power draw and condenser cooling. Many portable AC units have only one hose to vent the hot air from the condenser, which means it is venting the cooled room air. While this does help the AC some (cooler condenser equals happier unit), the air that is exhausted has to be replaced by something. That something is warm outside air sucked in through leaks in window/door seals, through outlets and switches via the dead space in the walls, etc.

If you go the portable AC route, look for one with dual hoses. These units pull outside air into the condenser stage and exhaust it back outside. Also, get another window shroud (as it appears you have two window openings, I could be wrong, to keep the intake and outlet airflow separated as much as possible as to avoid recirculating inlet and outlet air). Of course, the hoses will radiate some heat but keep them short or throw some double over towels over them and that should help minimize how much they radiate into the room.

Unfortunately, if your windows face South they're going to warm up under the heat of direct sunlight. There is not a whole lot you can do about the glass and the frame warming up and radiating into the room from the inside. I have seen some window films advertised as being able to reject heat applied to the inside but I haven't personally confirmed, and my admittedly limited knowledge of physics makes me question their validity. One thing you can do is put up layered curtains. If you use a single heavy curtain that one curtain will heat up and radiate into the room. But if you have two layers of curtains separated by even a small air gap it will help insulate the room from the hot window frame.

Source: Southern California native. We've had to get creative from time to time with heat management.

  • 1
    Honestly, without all the self-deprecation in the first sentence (removed), this is a reasonable answer, as you've actually added new details to existing answers.
    – FreeMan
    Jul 15, 2022 at 11:31
  • Appreciated. I just felt it would have been more appropriate as a comment to the other answer about portable AC units as to not 'steal', if you will, the thunder of the original answer involving the units. Hitting the point wall, again, rustled my jimmies, again. I suppose I still haven't gotten used to the stack format, typically conversing on reddit and such. Whether or not it ends up clicking for me, the SE network is still a great place for information full of knowledgeable people.
    – Tank R.
    Jul 17, 2022 at 3:42

Looking at that window, it's possible it can be detached--probably some clips along the metal arms that hold it in. This is so the outside window can be cleaned from the inside.

If it can't be removed completely, it can at least be adjusted so that it's not as in the way as before.

From there, a bidirectional window fan can be installed to help circulate air. It got me through my Massachusetts college time!


picture of fan to stop having to click through


It's a college, right? Does it have an architecture department? I'd walk through there and talk to random folks or hit their library for best practices in that case. Or perhaps a nearby school that has one... the general public is usually allowed access to halls and specialty department libraries (main libraries, no). You might also ask their facilities department if they have any ideas.

Now if you just need to hasten the changing of air, a fit-to-window fan may do the job. They make commercial units, but you can also do the old trick of "fit a piece of plywood, cut round holes and bolt 5-inch muffin fans to it".

Otherwise they make proper A/C units which allow ducts to be attached to condenser in/out. Obviously you want to dump the hot air overboard, but you might also try to intake the condenser air from the cooler outside, as A/C is very efficient when condenser input is cool.

You also might think about a unit that allows ducting of all 4 inputs/outputs so you can reverse it into a heat pump if you have a cold night.

  • I take it that the picture of the window A/C is not one of your windows. If it was you could just turn it on.
    – d.george
    Apr 19, 2017 at 17:02
  • @d.george that's right, the picture of the window A/C is not one of my windows. Apr 19, 2017 at 18:45

Place a small pedestal fan so that it blows on the opened window pane, and close the room door and any other room openings.

The fan will force room air out the lower opening, lowering the air pressure in the room, and drawing outside air in through the upper opening.

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