dehumidifier % in basement?

[bowtie]

First time home owner here. Purchased a dehumidifier for a finished 1500sqft basement. Just gathering some opinions on where the optimum % should be. When I plugged it in it was registering around 60%. Thanks

 

[ruger1800]

50%

 

[troy28]

as from my limited understanding the majority of the real bad mold can't start growing till at least 55%. that is not to say if your basement hits 55% you will instantly have the "bad" mold everywhere. Dehumidifier and just a little circulating air and no worries.

 

[ErickW]

40-60% is optimal humidity level in your home, in warmer and summer months. Depending how new or tight your home is you may even need to dehumidify in the winter.

 

[ws6guy]

I keep ours at 45%. However you shouldn't completely trust the gauge on the dehumidifier. In my experience they are usually off by 5%, either up or down. I go by a separate hydrometer across the room and adjust the dehumidifier accordingly.

 

[snorko]

On a related note, anyone have trouble with the unit freezing up in the winter? This will be the first winter I have one running in a 2,000 SF unfinished/unheated basement

 

[Indy_Guy_77]

On a related note, anyone have trouble with the unit freezing up in the winter? This will be the first winter I have one running in a 2,000 SF unfinished/unheated basement

If your dehumidifier is freezing up (summer or winter) - it's low on coolant. Either time to recharge it or replace if it can't be recharged.

-J-

 

[snorko]

If your dehumidifier is freezing up (summer or winter) - it's low on coolant. Either time to recharge it or replace if it can't be recharged.

-J-

Good to know. I dealt with several units on a part time job years ago and in the winter they would cake with ice. Mine is new so I should be good.

 

[Indy_Guy_77]

Good to know. I dealt with several units on a part time job years ago and in the winter they would cake with ice. Mine is new so I should be good.

Seems rather odd that they'd cake with ice only in the winter if they were in a basement.

I can see cold air being a small issue if they were in a crawlspace...

But running a D/H in a crawl space in the winter seems like it'd be a waste of electricity.

All a D/H is is an air conditioner. Ever see window units / central air units that have "frozen up"? Low on coolant - working much harder than they need to - temps of the important bits get too low and viola: block of ice!

 

[looney2ns]

The DH unit needs to be rated for low temp usage. I think they are supposed to run down to 45 degrees or so without freezing. Other wise they will freeze up when temp is much below 70.
They don't have to be low on gas to freeze.

More info here: Appliance411 FAQ: My Dehumidifier's Coils are Frosting/Icing Up, Why?

Insulate those basement walls, seal up the gapes in the bandboard area, your utility bill will thank you.
Then the DH will raise the temp of the basement while running.

Buy a Hygrometer. Don't trust the readings on the DH.

50-55% will keep the mold at bay.

 

[snorko]

Seems rather odd that they'd cake with ice only in the winter if they were in a basement.

Oddly enough this was on the third floor of a college library.

 

[eric001]

They will also freeze up if the filter gets clogged with lint. Some of the new ones have an auto shutdown for clogged filter, and some don't.

 

[Expat]

Mine never runs in the winter as the humidity level is naturally low during that time of the year.

 

[DragonGunner]

I got a big basement, about 70'x30', just got the one little electric humidifier set at 65% for years, no mold, feels just right and usually doesn't run much in winter. Its not a sealed basement, as theres no door to the staircase going down to it so maybe that helps. I know in summer when I come home I turn a fan on to blow up the stairs to the house and it it will cool the house a few degrees pretty quick.