geekhack
geekhack Community => Off Topic => Topic started by: tp4tissue on Fri, 03 July 2020, 15:47:07
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The basement is only ~300 cubic meters. Dehumidifier running 8 hours removed ~6 liters of water, measured in the bucket.
This morning the meter read 73 F @ 75% humidity
Now, it reads 75 F @ 63% humidity
The difference should be ~477ml of water, ~0.5 Liter.
How does this work ? is the humidity meter just busted ?
(https://i.imgur.com/hVaXskJ.gif)
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I think that there will be a base line or latent humidity that will not allow accurate measurement below some threshold.
My guess is that the device sucked out quite a bit of water in an initial (initiation?) draw down but can't easily get much lower.
A dozen of the machines working full time probably could not achieve a level below maybe 20%-30% in basement air because there is a near infinite supply of moisture in the soil behind the walls that can be pulled through continuously.
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The system must be extremely open, with more water coming in constantly, otherwise I can't understand how there's this much of it.
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Isn't the whole reason that damp basements are such a typical problem is that they're underground and subject to moisture coming in from the ground?
You've got 4 walls and a floors worth of surface area for ingress.
Regarding the achievable RH comment above. iirc standard compressor based dehumidifiers won't effectively work below about 50%. Dessicant/hybrid ones will go lower but are less energy efficient.
You could also supplement with a $5 temperature and humidity sensor as a second check.
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This is why people get sump pumps in their basement, because water obeys the laws of gravity
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Sump pumps handle liquid water in a pool.
This concept is about water vapor passing through concrete.
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I invested in one of these when I moved my room into the basement. I forget the specs, but it was one of the better ones (on paper). I have a hose running from its reservoir directly to the drain in the floor (not all dehumidifiers have this feature, unfortunately), since we've run one of these things before and I knew the sheer volume of water it could accumulate in a relatively short amount of time.
I set the thing to about 45% humidity, just because I want a margin of error to keep it roughly around 50%. During the summer, it runs almost entirely constantly. It is rare for me to go into the laundry room and not hear a trickle of water dripping from it into the drain.
That basement was gross before. It smelled, it was musty, everything in it would accumulate some sort of grunge/film over time. Steel would literally rust down there. Yes, this is all in spite of a functional central air system. I'm glad I invested in a decent one, because the difference is night and day.
Without the humidifier on, in the summer, I'm pretty sure that basement can reach upwards of 75-80% humidity.