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Community and Q&A

Air conditioning (off-topic)

Mark Walker | Posted in General Questions on

My 99 y.o. Granny-in-law lives on the top floor of a rent-subsidized retirement home. She can’t have a window air conditioner hanging out the window and her portable air conditioner (with hose to window) simply doesn’t get the job done.

What kind of work around could I do to use a window AC but not have it hanging out? The window ACs have vents on the sides which make things more difficult.

Climate zone 4c. Yesterday was officially 98F.

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  1. Expert Member
    Zephyr7 | | #1

    There are two kinds of spot coolers, which is what the little floor-sitting air conditioners are. The cheaper kind usually has only one exhaust hose, so it sucks some of the air in the cooled space out to cool itself off while it's running. The more efficient kind has two hoses that go out, one brings air in, the other blows hot air out. These kind don't pull conditioned air from the interior space. It's similar to how sealed combustion furnaces work. I'd try to get one of those units as an upgrade as a first step since the installation would be easiest.

    The requirement for "nothing hanging out the window" is probably for safety to people on the ground below. You might try a mini split type of system, that has a smaller outdoor unit, but that would require more installation work and the OK of the building management people. Mini split systems are a permanently installed option, so that might pass muster with the building people.

    You could potentially rig something to use a window mount air conditioner as you describe, but I wouldn't recommend it. Try to find a spot cooler as I described above, and make sure it's big enough to handle the space you have. Another thing to try is to use some reflective window shades to limit solar gain (sunlight heating the space during the day).


  2. Expert Member
    Dana Dorsett | | #2

    By "...hose..." rather than "hoses" to the window, I'm assuming it's a single hose portable. If true that is THE problem.

    A single-hose portable craps out on capacity with rising temperatures due to the fact that it is pulling outdoor air into the room. The hotter it is and the higher the duty cycle, the more the capacity degrades. The labeled performance is never met, since it's counting on INDOOR air entering the condenser coil side, not outdoor air, and that indoor air exhausted from the room, replaced by hot outdoor air. The hotter it is, the less cooling capacity it has. It's much worse than just not having enough rated capacity. At 98F outdoors a single hose portable delivers WELL UNDER HALF it's labeled capacity.

    By contrast a dual hose portable keeps the outdoor air contained within the hose & cabinet on the condensing coil side, never mixing with indoor air, and runs pretty much at it's rated capacity.

    For diagrams and more detailed explanation see:

    (note the chart: a 12,000 BTU/hr unit delivers only 4400 BTU/hr of cooling @ 98F outdoors.)

    See also this related thread:

    1. Mark Walker | | #3


  3. dionport99 | | #4

    I think that instead of stopping opting for portable air conditioning, you should look for other models that if they can fulfill their functions perfectly, in the market there is a variety of these air conditioners and that little by little have been improving the performance of these. I have one and the situation was similar to your grandmother's, I bought another and I do not complain about it until now, it has been up to the task.
    You can look at some interesting models here:

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