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Standalone dehumidification required in zone 4a?

qbrt | Posted in General Questions on

I’ve lived in an 1100 sqft NYC apartment for a number of years but recently bought an old townhouse (3 story, ~2500 sqft) that I’m bringing up to modern spec. My experience in the apartment is our AC gets the place plenty cold (~72F) but doesn’t do enough humidity (60-65%). To counteract this, I bought a 35 pint dehumidifier which fills up twice a day during the summer and once a day during the spring and fall.

I often see advice that standalone dehumidification is a waste of money and energy, and the AC system should handle it. However, this isn’t my experience and was curious what other people in similar climates observe. I don’t want to pay to install a dehumidifier that I don’t need, but I also don’t want to finish building the house to discover I really should have put in ductwork for the dehumidifer.

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  1. walta100 | | #1

    Sounds like the classic symptoms for an oversized AC system.

    You may want to upgrade your thermostat to one that can try to control the humidity by overcooling.

    If your set point is 72° the unit will run until the room is 70°. The longer run time and lower temp remove more moisture. The Ac will start the next cooling cycle when the room gets over 72°

    I found the link for the Ecobee thermostat that shows its setting for this feature.


    1. qbrt | | #3

      Like most NYC apartments, I don't have a thermostat -- I have window units :)

      You may be right about oversized AC during the summer. I will have to check the BTUs on my window units -- I didn't buy them, they belong to the unit owner. However, my AC basically doesn't run during the shoulder seasons. NYC spring and fall are very nice...except for the humidity. It's somewhere around of 60-70% RH year round, even when the temperature drops below where you really need AC.

  2. Deleted | | #2


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