I live in a two story apartment and I'm in the top floor. The apartment is pretty old, 54 years old. Due to that, the insulation is really lack luster. The windows are single paned walls are relatively thin.

Even if I keep my windows covered and windows closed, after a hot day, the room becomes a sauna when I get home at night. It's cool at night so I just have to vent the heat out. However, during the day, r it is almost impossible to get the AC to make much of a difference. I have to stand in front of the AC to feel cool. The AC feels plenty cold and strong and my apartment isn't very large(<600sqft).

What is causing this? Is the cool air simply escaping? Is it all the heat coming through the windows? I have pretty thick light blocking blinds.

What can a renter do to make the apartment a little nicer in the summer?

  • What is the size of the A/C unit, in BTU or tons/hr? Is it a window unit? What color is the roof? Yes it matters. Commented Apr 28, 2017 at 22:00
  • @Harper its a window unit. I have a portable one in my bedroom as well that is 8000 btu. The one in the living room seems more powerful but it is an old frigidaire, can't tell what btu it is. I'd say at least 10k. roof color is tan brown
    – mugetsu
    Commented Apr 28, 2017 at 22:03
  • Model number? You can usually find BTUs from that. Commented Apr 29, 2017 at 5:41
  • My son has a house with a 3 sided sun room,about 25'X30'. The 3 walls are mostly glass single pane (5 foot high windows). Even with no one in the room the 2 10,000 btu window A/C units struggle to cool the space due to sun exposire on the glass.
    – d.george
    Commented May 3, 2017 at 10:24

2 Answers 2


Get a reliable thermometer and measure the temperature difference between the supply and return air. Run the unit for 15/20 minutes then check the temperature difference. Standing in front of the unit does not tell me anything. The size of the A/C needed is dependent upon the construction and orientation of the area to be cooled. You may need to run the A/C unit all day to reduce the humidity and to keep your room cool. If your area has high humidity, reducing the humidity will take a lot of the units capacity As others have said, you need to find out the size of that unit. Every thing said above will determine the size of the unit needed to cool your area.The more information you present the better advice you will receive.

  • Many years ago a rule of thumb for an older non insulated Pittsburgh home was 600 sq. ft. of living area to 1 ton of A/C (12,000 BTU's). Adding wall insulation , thermopane windows, and an attic fan to reduce the attic temperature, would raise the square footage area to about 900 to 1000 sq. ft. for the same size A/C unit. That is figuring a house with 4 walls and a roof. Your space is an apartment that is only part of a building and is Probably facing towards the sun., So you may need a larger than normal A/C unit. Just food for thought.
    – d.george
    Commented Apr 30, 2017 at 11:37

there is a proportion to be observed for the air to be cooled down, between the square feet of the whole area (home or apartment) against the basic "1 ton" of equipment capacity. One ton = 12,000 BTU which is barely enough force in your a/c unit to transform the air of 400 sq.ft from hot to fresh.

I hope this gives you the idea how to size the equipment properly according to the square footage.

  • It depends massively on the outdoor temperature, insulation, windows etc. 1ton can do 1000+ sqft in a new home. Commented Apr 29, 2017 at 5:41
  • user69064--- What does your statement mean?
    – d.george
    Commented Aug 21, 2017 at 11:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.