Should I buy another window ac or a dehumidifier to mitigate mold growth?

Details: loft style 500sqft apartment with an oversized "window ac" unit upstairs that's meant to cool the entire apartment. Ac cycle only stays on about 5m even on "low mode". Causing moisture to stay in the air because the unit doesn't stay on long enough to dehumidify. The warmer air downstairs and outside, mixed with the moisture output from the ac upstairs is causing mold to grow on everything. 

Question: would it be more effective to get a dehumidifier to keep moisture low, or get another window ac for downstairs? 

Concern: another window ac (downstairs) might not be able to pull the moisture from upstairs 

9 Answers

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  • 2 months ago

    def dehumidifier but i dont know your condition of the area but  around 75 and 85 are the perfect conditions for mold to grow i just know ac units can drop water and since there is mold present then there is already signs of humid conditions... just the dehumidifier will cost a little more. dont need a thumbs up just want you to be aware of the conditions each unit will do (ac or dehum.)

  • Mr. P
    Lv 7
    2 months ago

    Find out what is producing the moisture in the air to build up. It will always encourage mold on the coldest areas.

     You need an extractor fan above your cooker, and one in the bathroom to remove damp air. If one wall is cold and encouraging mold - put a fan near it to improve airflow over it and allow it to dry. Paint that wall with mold resistant (kitchen) paint. There may even be a water ingress problem in that area from outside.

    Ceiling fans will help, also having windows that open at the top will let out hot air. Ideally you want to let in cold air at night on the lowest floor, and have a wind tunnel effect to let the hot air out on the top floor. This will cool the whole structure during the night so it will be cooler during the next day.

    If your walls are getting full sun heating them then it is more effective to install a shade panel outside than run an air conditioner all day.

    Think of better building design rather than spending cash keeping it cooler.

  • 2 months ago

    Air conditioners are not fixes for a mold problem. You DO need a dehumidifier. Pulling the moist air out will go a long way toward making your AC unit run better, too. AC units pull air from OUTSIDE into the interior of a room. If that air is humid, you're not fixing anything by running the AC. You definitely need to use a dehumidifier. 

  • Anonymous
    2 months ago

    Dehumidifier is much better for mold . It gets worse with if you have wall to wall  carpet . 

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  • 2 months ago

    You definitively should get a dehumidifier. In case you don't know, unless properly sized, an air conditioner will increase the humidity. That's because humidity is relative to temperature. Change the temperature and you change the humidity, even though the water content in the air remains the same.

    If you walked into a room that was at 50% humidity and turned up the heat, the humidity would drop and it would become drier even though the water content of the air is unchanged. If you lowered the temperature instead, the air would become wetter (more humid). It would be like if you had a sponge that was half full of water (50% humidity). If you start squeezing the sponge (cooling the air) then a point would be reached when the sponge would start dripping water (100% humidity). So the sponge would be at 100% humidity at that squeeze level (temperature). So you very the RELATIVE humidity of the sponge by squeezing it even though the water content (absolute humidity) is the same.

    Your air conditioning is causing the mold problem because it is increasing the relative humidity. If your A/C was able to "over cool" the air it could extract moisture from it and lower the humidity. But a window A/C unit usually isn't that. Adding another unit downstairs would only make the situation worse. You need a dehumidifier.

  • Anonymous
    2 months ago

    Put the oversized ac downstairs, set it to a colder setting and high fan, put a fan in the loft  and see if it improves the humidity issue.  If not, get another ac upstairs.

  • 2 months ago

    first, suggest a major size [ceiling] fan to circulate the air.  You'll probably want that anyway ... and then the dehumidifier.  another a/c won't accomplish much -- it won't run longer  -- grampa

  • 2 months ago

    You could try turning on a fan..or even finding where the temperature reading is on the unit and cover it with cardboard...or a dehumidifier

  • y
    Lv 7
    2 months ago

    Dehumidifier, You can control the humidity levels to ensure your comfort and safety. They will also reduce the run times on the AC becouse the AC will no longer waster energy, removing as much moisture in the air.  I have central AC and still monitor humidity levels and such, when they start creeping above 60/65, it's time to turn on the dehumidifier. 

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