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DRSMPS
Explorer
Jul 08, 2013

Humidity at Night

We just got back from a week long trip to Michigan. The trip was great with our only complaint being the humid conditions both inside and outside the RV. It rained just about every night and the outside humidity was near 80% with temperatures in the low 80's.

Inside the RV was also humid. I experimented with the AC settings to try and drop the humidity as much as possibly. Still at night the humidity inside our 21ft TT would climb to around 70% with a temperature setting on the t-stat of about 72 deg F. Over the course of the week I tried several things to drop the humidity. Ultimately, I found turning the AC off in the afternoon and then on just before bed would drop it to the 55% range. However over the course of the night it would climb back up to 70% again making for an uncomfortable sleep.

This is the first time I experience this to this extent. Does anyone have any recommendations for dropping the RH inside the RV? Is my 1.5 ton A/C too large for the TT to draw out the humidity? Does anyone run a dehumidifier inside their TT?

14 Replies

  • You can also run an oscilating fan which moves the air around. This in itself will reduce humidity, add the AC and you should be good. We are from MI, in MI right now, so we know what you have been experiencing. We have our AC on and the humidity level in our motorhome stays around 55%. We keep all doors, windows and vents closed and are using the 13,500 btu unit.
  • This is why for almost everyone the 13,500 AC works the best… the 15,000 is to big…

    The real and bigger problem is inefficient insulation and rapid air exchange…

    The 13.5 was far too big for my old 20 trailer…

    Running a heater to force the AC to run longer might work, but is extremely counter intuitive… unfortunately energy efficiency isn’t even in the RV industries vocabulary…
    You would be far better off with a smaller AC than running a heater…
  • X2 on heat and AC. Our newest locomotives, they removed the adjustable thermostat for the AC, so I turn on the strip heaters and run the AC and it helps.
  • Hi,

    Run the air conditioner AND a small electric heater (about 500 watts). The heater will cause the air to remove a whole bunch more moisture.

    Otherwise, what happens as the end result, is cold and clammy with high humidity.

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