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Community and Q&A

Dehumidifier in home

DANIACHUCK | Posted in General Questions on

Last year I replaced my ac with a new system.  Everything was well with no issues.  2 months ago, the city of Dania installed soundproofing/Storm windows and doors.  The added a fresh air intake to my ac.  They also added insulation to my attic.  Problem am having now, is that the ac vents sweat and water drips and home smells of humidity.  My NEST says humidity is at 58%.

How can I address this?  Do I need to install a whole house humidifier?

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  1. Jon R | | #1

    Try a portable dehumidifier (much less expensive) first. Also verify that the fresh air intake isn't more than needed and that the AC fan doesn't run continuously.

  2. Trevor Lambert | | #2

    58% doesn't seem excessive. My house has been in the high 60s a lot this summer, and we have no "humidity smell" .

  3. Expert Member
    Zephyr7 | | #3

    You probably have too much makeup (outside) air coming in and it’s overwhelming your system’s ability to dehumidify the air. It’s easy to test this, just cap off the makeup air intake temporarily and see if that makes the problem go away. If no makeup air = no humidity problems, then you know what’s going on.

    If you have too much makeup air coming in, you need to adjust things a little. Running a dehumidifier is not an energy efficient way to solve the problem you’re seeing.


  4. DANIACHUCK | | #4

    Thanks for replies.. WIll try.

  5. DANIACHUCK | | #5

    2 days ago when I posted this, I openned the fresh air intake that was installed. (I had it closed). This morning my NEST says outisde temp is 84, inside temp is 72 and inside humidity is 84%. That is excessive.

  6. Walter Ahlgrim | | #6

    My guess is the old AC unit was 2-3X over sized as many are and after the improvements it is now 3-5X oversized. The way to tell if this is correct is to time how long the unit runs each cycle Nest may keep a log for you. To remove humidity you want to see run times over 15 minutes.

    If you are in FL you may want to run a portable dehumidifier mostly for the humid days when the outdoor temp is about the same as your set point so the AC runs very little.

    I think Nest has a “cool dry” mode you may want to try if you have not.


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