Dehumidification project

Other than noisy, energy-wasting, labor-intensive* dehumidifiers is there any way to keep my basement dry(er)?

[*labor-intensive because I am unable to have it empty directly into floor drain.]

You could fix the problem with it not draining. Do you not have a sump pump? That’s your first problem. There are several ways you could fix the draining problem. Essentially, either :

  1. Get a dehumidifier with a built in condensate pump and run a tube up (probably through a hole drilled in the ceiling) to a drain upstairs or outside.

  2. Buy an energy star rated dehumidifier and a separate condensate pump.

  3. Depending on how the ventilation and HVAC is routed, it might be possible for you to move air instead of liquid. If there’s an air return duct, it might be possible to tap into that duct or opening and have the dehumidifier unit be upstairs near a drain.

Now, what other options are there? If the air outside your house is dryer than inside, you could potentially exhaust moisture using an energy recovery ventilator. Those are more than dehumidifiers, though - $1000 or more. And they are a lot bigger job to install than just buying a dehumidifier, sticking a condensate pump in the drain pan, and running some clear pex tubing through a small hole in the ceiling.

I don’t think you can stop the seepage that is actually making it humid - I would imagine you would need to basically demolish the house, redig the basement, and build the basement again using a type of concrete that is less permeable to moisture. (basically the same concrete they use in swimming pools might work)

Like this one :

As for energy wasting. Well, the first energy star rated dehumidifier is this one :

Let’s see. 310 watts. Assume it runs 2/3 of the time (it has a humidistat). 148 kilowatt-hours per month. At national average electric rates of 12 cents per kilowatt, that’s $17.76.

If you even own a house with a basement at all, your monthly expenses are probably more than $1000, so that’s kind of a drop in the bucket per say.

Oh, an addendum : so these guys claim the FFAD7033R1 is the best and most efficient dehumidifier on the market. And they give some numbers : in a 40 square foot test room, from 90% humidity down to 40% in 10 minutes. Well, if your basement is 900 square feet, It would take 22 times longer. Let’s say it has to do this 4 times a day because your basement is constantly seeping. So it would run 15 hours a day. It draws 645 watts at full power. That would add 290 kilowatt-hours to your electric bill per month, or $34.

That’s a rather pessimistic estimate, however, Your basement might not seep nearly that much. So I would actually expect a fraction of that. Supposedly this model is fairly quiet.

Is your basement finished or unfinished? Poured concrete walls or cinder block? Sealed concrete floor slab?

One more bit of information. I decided to research dehumidifiers, and found this list :

The most efficient dehumidifier, per the government, you can readily buy is this model :

It’s $160 more expensive than the Frigidaire model, but you get the condensate pump included, so effectively the price difference is $120. It is significantly more efficient - about 50% - you would save that price difference on your electric bill in a year or 2, probably, depending on the actual moisture load in your basement.

More about my circumstances: Live in Michigan with very damp summers. 1,500 +/- sq. ft. Basement is finished. It has a floor drain but that was sealed because a radon mitigation system was installed when we bought the house 5 years ago. There is no sump.

Would this plan work?:
I could buy a new, energy-efficient (quieter?) dehumidifier (currently using ancient-but-effective model) and build a platform so it would drain into our laundry tub. However this would put it in a “distant” separate room and I am under the impression that it should be centrally located to work effectively.

As long as there’s plenty of air circulation between the rooms in the basement the exact location of the dehumidifier is mostly immaterial.

So a dehumidifier in a closed broom closet is bad. A dehumidifier in a bedroom is fine if the door to the main room is open and fans in the various rooms are keeping the air moving at least a little. Stagnant air is bad no matter what’s going on with humidity.

You don’t need to build a platform if you can patch the hose into the very drain the tub uses. My tub just goes into a piece of PVC pipe and then into an open (small) hole for a drain, so I run the hose into the open hole. But if the hole were sealed I could trim the pipe and use a coupler to accept the wash tub pipe and dehumidifier hose and route them both to the drain.

That Whynter model I linked above comes with a hose and a pump. So you just place the unit somewhere convenient with good air circulation and run the hose to the laundry tub. You do not need to bother with the platform, the pump is capable of pumping water vertically. Specs say it can do 15’ vertically. Per the Energy Star Guide, the Whynter model Efficiency (Energy Factor) (L/kWh) is 2.8. The most efficient dehumidifier they have ever tested is 2.89, and I suspect from the descriptions it costs over $1000.

Do you know why it is getting wet? Are you able to stop more of the moisture from entering the basement in the first place?

We had a similar situation about 6 months ago. I bought a dehumidifier and plumbed its effluent to drain into the AC’s condensate pump. But what really helped the most was investigation that resulted in some (human-powered) re-grading around the house and re-plumbing some outdoor drains, too. Ours was really simple stuff, actually.

A few simple things. How are your gutters working? Are they draining properly or is water spilling down your outside walls down to the foundation?

Walk around your house, is there anywhere that the ground is sloping to the foundation instead of away from it? If so guess which way the water is draining.

Either of those could be significantly increasing the humidity in your basement and both are not hard or expensive to fix.

Don’t have a problem with water intrusion just extreme dampness.

If the air is materially more humid down in the basement than the rest of the house when everything is closed up and the HVAC is off then you do have water intrusion. Maybe not liquid standing water intrusion. But you do have water vapor intruding from somewhere.

This excess vapor can be due to saturated soil from inadequate surface or subsurface drainage. Or due to basement wall cracks, porous floors, inadequate or deteriorated waterproofing on the outside surface of the basement walls, etc. Or, like one of my former neighbors, a small spring-fed creek the developer buried with fill then put the house on top of.

That water is not getting into that air by magic. And the process of it getting from the soil into the air is slowly eating the basement’s walls and/or floors.

Using a dehumidifier to combat “extreme dampness” is like installing a bigger bilge pump on a leaky boat. It’ll work for awhile but it’s just a symptom masker; not a cure.

Depending on the totality of circumstances a cure may not be affordable and masking symptoms may be plenty good enough. Better to make that decision deliberately, not inadvertently.

It may be as you write, LSL Guy, but I don’t think my basement is any different than most basements in states with humid summers. I’ve owned a dozen homes (and lived in another half dozen) and they all had damp, musty basements. Dehumidifiers work great but I find the noise obnoxious.

There are quiet, DC driven fans you can buy of various sorts. What you could do is put the dehumidifier into a room with a closed door - like that laundry room you mentioned - then use a pair of quiet fans to actively circulate air into that room and back out.

Like these : 0.6 sones. That’s quiet.

(Delta BreezeGreenBuilder)

They are bathroom fans but nothing stops you from installing one in a wall and bringing the duct to the dehumidifier intake or installing one at the dehumidifier exhaust.

Or these :

These are meant for installation in a wall.

Improve the ventilation when the outside absolute humidity is low , and would give you dry air even when the air cools to the daily (eg night time, early morning) low temperature.

Turn it off when the absolute humidity of the outside air is high enough to cause high relative humidity when the place cools down.