Ideal/max RH [relative humidity] for finished basement

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newbie003
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Ideal/max RH [relative humidity] for finished basement

Post by newbie003 »

What should the RH be in my finished basement (and what's a safe max)?

I had been maintaining it at 50% with a portable dehumidifier (during/after work had been done in my basement and my Santa Fe dehumidifier was disconnected), and finally had the basement company reinstall my Santa Fe.

Now I can't get the RH below 63% even with the Santa Fe running non-stop.

Thank you.
Last edited by Misenplace on Thu Jun 10, 2021 4:27 pm, edited 1 time in total.
Bapple1420
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Re: Ideal/max RH for finished basement

Post by Bapple1420 »

Your dehumidifier is undersized, and you likely need higher air flow rates through the unit to get to a target relative humidity of 40% to 50%
Topic Author
newbie003
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Re: Ideal/max RH for finished basement

Post by newbie003 »

This is my unit: https://www.santa-fe-products.com/wp-co ... Manual.pdf which I think is actually/possibly overkill for my 700 sq ft, and I have the duct kit to help air flow from utility room (where it's located) to the finished space.

I think it's just not working right :(
livesoft
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Re: Ideal/max RH for finished basement

Post by livesoft »

I have some thermometers/hygrometers around the house and outside. Right now it is about 85% Rel Humidity outside heading to 95%.

Inside the house is about 53% to 65% Relative humidity over the past few days.
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lthenderson
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Re: Ideal/max RH for finished basement

Post by lthenderson »

newbie003 wrote: Thu Jun 10, 2021 9:07 am What should the RH be in my finished basement (and what's a safe max)?

I had been maintaining it at 50% with a portable dehumidifier (during/after work had been done in my basement and my Santa Fe dehumidifier was disconnected), and finally had the basement company reinstall my Santa Fe.

Now I can't get the RH below 63% even with the Santa Fe running non-stop.
What was the work done in your basement? Certain jobs like drywall mudding or texturing can add a lot of humidity to your house and take a long time to lower, especially when normal humidity levels are high at this time of the year.

Is water draining out of the hose when in use? This should give you a good idea if it is a working issue or just just a high humidity load.

You should always try to keep humidity levels inside below 55%. Above that for extended periods of time you run the risk of mold developing.
Topic Author
newbie003
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Re: Ideal/max RH for finished basement

Post by newbie003 »

lthenderson wrote: Thu Jun 10, 2021 2:50 pm
newbie003 wrote: Thu Jun 10, 2021 9:07 am What should the RH be in my finished basement (and what's a safe max)?

I had been maintaining it at 50% with a portable dehumidifier (during/after work had been done in my basement and my Santa Fe dehumidifier was disconnected), and finally had the basement company reinstall my Santa Fe.

Now I can't get the RH below 63% even with the Santa Fe running non-stop.
What was the work done in your basement? Certain jobs like drywall mudding or texturing can add a lot of humidity to your house and take a long time to lower, especially when normal humidity levels are high at this time of the year.

Is water draining out of the hose when in use? This should give you a good idea if it is a working issue or just just a high humidity load.

You should always try to keep humidity levels inside below 55%. Above that for extended periods of time you run the risk of mold developing.
The work was indeed drywall, mudding... but that was a couple of months ago and long-since solved by the portable dehumidifier which did a great/nearly instant job of lowering the humidity (from 75+) to basically whatever I set it at (60, 55, 50, 45...). After that, the humidity was generally around 68 or so, so I continued to use the portable until the basement company could come out to keep up the big Santa Fe. After about 24 hours (at perhaps a 50 or 55% setting), the portable (https://www.bestbuy.com/site/ge-50-pint ... Id=6390682) would be about half full, so maybe around 1 gallon of water if my math is right, give or take.

There is minimal water draining out of the Santa Fe, so it's not entirely dead, it's just not working well. It seems to be more of a drip, drip, drip than a constant flow. This is why I think it's a working issue vs. a humidity issue (I'd feel much differently if the humidity level wasn't dropping but water was pouring out, as that would of course indicate high humidity).

Given that I likely need a new unit, any thoughts on what to get? Brand/size/etc...? I'm not sure if my current unit is actually oversized, or if it's better to be oversized given that it has to pull via the duct kit, and isn't in the actual finished space.
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lthenderson
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Re: Ideal/max RH for finished basement

Post by lthenderson »

Assuming your basement temp isn't below 65 degrees (page 4 in the manual), it sounds like it isn't working properly. I would probably verify with another hygrometer and then try to exchange or return it. I don't have a dehumidifier other than my A/C unit so no recommendations.
BIGal
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Re: Ideal/max RH [relative humidity] for finished basement

Post by BIGal »

I have been quite satisfied with our Frigidaire 70 pint unit. They also make a smaller size. Expect to pay quite a bit for these units, however, they have an excellent warranty and they are worth it. You will have to do some calculations to determine what size you need. I have a hose connected to ours and then run to a drain in our mechanical room so I don't have to constantly empty a tank. Good Luck
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newbie003
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Re: Ideal/max RH [relative humidity] for finished basement

Post by newbie003 »

BIGal wrote: Thu Jun 10, 2021 5:03 pm I have been quite satisfied with our Frigidaire 70 pint unit. They also make a smaller size. Expect to pay quite a bit for these units, however, they have an excellent warranty and they are worth it. You will have to do some calculations to determine what size you need. I have a hose connected to ours and then run to a drain in our mechanical room so I don't have to constantly empty a tank. Good Luck
Is the unit in your mechanical room and vented to finished area, or is it located in finished area? thanks!
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