Basement Humidity Remedy?

13 Replies

So, in a few of the single family houses I have recently purchased for rentals, the basements are fairly humid.  The real estate agent that I've been using (who is fairly well versed in investment purchases) suggested placing a dehumidifier in the basement to help control the moisture.  

However, my property manager advises against purchasing/placing dehumidifiers as she feels that the tenants may disconnect, break, or steal them.  In searching for alternatives to a dehumidifier I've found some of the below solutions... 


1 - This looked relatively inexpensive, but requires a window in the basement (which may not be present), and is very much DIY:

I found 2 - 5 on the following site:

2 - Placing Charcoal bricks around the basement

3 - Filling a bin with rock salt and drilling a few holes allowing for water to drain

4 - Buying desiccant's and placing those around the basement

5 - Running an electric heater, set no higher than 95 degrees.

I really like option 1... but if my basement doesn't have a window, it won't work... I'm also not that mechanically inclined.

I'm not so keen on solution 2-4 as it would require intervention from the tenant to cleanup and replace used up portions, and I'd really like the tenant to not have to think or worry about placing or emptying stuff.  

I'm not really excited about leaving an electric heater running unattended, nor do I think that curious, uneducated minds would think it was necessary to run one in an unoccupied space, nor would they appreciate the extra heat in summer, or the extra expense added to their electric bill.

I'm wondering if anyone has tried any of these, or if they have success doing something else to help cure a damp basement.

Thanks in advance.

We have that first thing you posted, except that it was a professionally installed unit that was manufactured and it looks nicer than just open duct work as the area it is used in is a finished bedroom in the basement. It works well in the room, but it doesn't dehumidify anything but the 10 by 10 area it is in so we need to use a portable in the bathroom and the closet.

If you like the idea of #1, you can get a real duct fan like this:

I'm curious to know how it works though.  I've been putting dehumidifiers in my rental basements.  I get smaller ones, energy star, so they don't suck as much electricity.  I mistakenly got a larger one for a larger basement - and the electric bills were HIGH!  Oops!

Anyway, not a bad idea... I may try it out!

@Lee L.   - Thanks much for the response. 

How much did it run you to have it professionally installed?  

If you didn't have a wall acting as a barrier to other areas in the basement, do you think that it would dehumidify more?

The problem with passive dehumidifiers is that the humidity is coming in with the outside air. Moving the basement air outside is resulting in it being replaced by more outside air of the same humidity level. Without using a dehumidifier, which must run constantly, in itself is not actually reducing the humidity levels in the home. A dehumidifier actually maintains a reduced humidity level.  

Buy them on sale, used etc. and check them regularly to insure the tenants have not turned them off if they are paying for hydro.  

I think it is quite possible that it would dehumidify a larger area but for the walls, but ofcourse who knows for sure.

I have no idea on the install price because we got the house when an aunt died and she had it done way back right after hurricane Irene flooded the whole basement, but there wasn't a choice on pro install because a hole had to be cut into the foundation as there was no window, I have a feeling if a venting spot existed it would be a pretty easy diy project.

I'm installer of user of direct vent fan with humidistat. vent heavier moist air near floor, and replaced by air exchanges min 3 per pp x day. installed $1500-$2500 vents  aprox 2000-4000 sft. 

depends on region and avg humidity levels. 

a whole active not passive cs basement vent 230cfm more. installed into wall is vent like #1,  with 

3-4 manufacturer's in no. America.

but must air seal as it will bring warm air from conditioned spaces to basement. 

dehumidifier produces heat as by product, and takes more electric to operate. 

if go with dehumidifiers get large comm heavy ones with humidistat and direct drain. no one will walk away with it. 300lbs

dont just open window unless dry air cat 1 wind blowing straight in.

it wont remove moisture only feed it. 

i use activtek  air scrubbers secured to a bracket holding plate. 

it kills protects 2000-10k sqft of mold bacteria, and reduces moisture as its byproduct of technology esp basements.

@Jared Broderick A dehumidifier is $200. I have never had a tenant steal it and if they did I would just buy a new one with their deposit. I wouldn’t mess around with anything else. If you are concerned that they will turn it off, you could just hard wire it back to a junction box.