Condensation in Basement

[velvetfoot]

Water is condensing a whole lot on the well tank, water softener tank, and cold water pipes near the well tank.
There is some rust on the lower weld on the well tank.
I am resisting running a de-humidifier because of the energy use.
I have a small window open in the basement as well.
There is no or not much odor down there.
Most of the water usage is in the evening, and since it is from a deep well, is nice and cool.

I could put some anti-sweat insulation on the tanks and the pipe I guess, or just run the de-hudifier.

Any ideas? I'd like to save energy.

Thanks.

 

[saichele]

The rust on the well tank weld would make me tense. It's presurized and will make a mess fast if it goes. The rest of that stuff is basically aesthetic.

First off I think I'd try to get the tank dry enough to wire brush and hit with some galvanized paint. Once the rust is contained, you could try a water heater blanket. But I'd definitely check up onthat weld...

Steve

 

[Sandor]

First of all, the tank has a rubber pressurized bladder inside. So, even if the weld did get a hairline crack in it, it will not leak... as long as the bladder is not broken.

Is the basement waterproofed? If so, how?

Is the HVAC ductwork in the basement ceiling?

 

[saichele]

I think it depends on the age of the tank. I know my parents house had a bladderless one (c. 1955), and the one that replaced it inthe early 80's only had a bladder for the air charge at the top.

Newer ones may have bladders in both sections, but even a pinhole in one of the older types will leak pretty fast.

Steve

 

[the_guad]

IMHO, do yourself a favor, get a good dehumidifier that can operate on a relative humidity setting and run it to the nearest drain. It will only kick on when the relative humidity rises above the set point and then will shut off. Humidity is one thing, but when it's condensing on surfaces you run the risk of shortening the lifespan of everything the water touches. I'm sure that the appliances you have in the basement aren't cheap. I run a dehumidifier in the summer and the basement is much more comfortable for it.

 

[velvetfoot]

Thanks. I am thinking that even if I do run the dehumidifier there will be condensation because the well water is quite cool. The dehumidifier I bought a couple of years ago was rate "Energy Star", by Longhi (sp?) and it runs the fan even after the preset conditions are met. I should probably figure out how much money it actually costs to run (depending on relative humidity conditions) and then see that being such a cheap b-d doesn't make cents.

 

[ourhouse]

We had the same problem with condensation. We bought the bigest dehumidifer we could get from Sears and it took care of our problem.

 

[suematteva]

Traditionally we have had a very damp basement. This year while cleaning out my folks basement, I came across an old dehumidifier from my grandparents house. I figured try it out..Have not looked back since..In the spring it did ice up a time or two but mostly because the cool temps and stove not running..It has the automatic switch mentioned above and it works great..The basement remains cool but very dry..we would get some of the sweating you mentioned on the main supply line. The last couple days have been humid only high 70 s low 80 s will see when we get the real warm stuff.

The Mrs. used to run the fan on the hot air system. not any more..

 

[wg_bent]

I'm dealing with this problem in spades these days. See my post here in the green room titled Basement insulation. My take is that you need to use a dehumidifier once the house is built. If you would have put insulation and moisture control on the outside of the foundation, then your good to go. Otherwise, you need to control the humidity level inside. What I'm concerned about now is that once I get the basement insulated to my satisfaction (it will be at least r23 when done (r10 due to the insulpink, r 13 from the non-faced bat insulation (plus what ever a concrete block wall is...(r -2?)) seriously, probably r 1.72, for a total of R 24.72. Hmmmm...better than my upstairs at r19. So my concern is that the de-humidifier will cause the basement to get hot. It will act as a small heater. Would it be better to put an airconditioner in the window? I have an office in the basement, and don't want it to get too hot in the summer. Thoughts?

Warren

 

[BrotherBart]

So my concern is that the de-humidifier will cause the basement to get hot. It will act as a small heater. Would it be better to put an airconditioner in the window? I have an office in the basement, and don't want it to get too hot in the summer. Thoughts?

Warren

A very valid concern. I moved my office to the basement this winter. I finally had to turn on a dehumidifier today and the temperature has started going straight up.

I just found this link. Not sure I buy it yet but we shall see:

http://www.misterfixit.com/dehumifaq1.htm

 

[Todd]

I have the same problem with my basement. Very cold well water. I put a water heater blanket around my water tank and softener. Also insulated copper water pipes. It helps some, but still have a few wet spots even with the dehumidifier going. My dehumidifier is an older type so maybe I need to find a new efficient model?

 

[elkimmeg]

On the east coast, we all have this problem. Too much rain equates too to much moisture in the ground and air.
Part of the problem is cool metal contact with humid air. The metal acts llke a magnet collecting moisture / condensation.
What we need is a few dry days and some fans or as suggested insulation and dehumididfiers

 

[wg_bent]

On the east coast, we all have this problem. Too much rain equates too to much moisture in the ground and air.
Part of the problem is cool metal contact with humid air. The metal acts llke a magnet collecting moisture / condensation.
What we need is a few dry days and some fans or as suggested insulation and dehumididfiers

So you think I'm on the right track then Elk? I sure hope the Mrs. approves a stove in the basement this winter!

 

[Sandor]

I'm dealing with this problem in spades these days. See my post here in the green room titled Basement insulation. My take is that you need to use a dehumidifier once the house is built. If you would have put insulation and moisture control on the outside of the foundation, then your good to go. Otherwise, you need to control the humidity level inside. What I'm concerned about now is that once I get the basement insulated to my satisfaction (it will be at least r23 when done (r10 due to the insulpink, r 13 from the non-faced bat insulation (plus what ever a concrete block wall is...(r -2?)) seriously, probably r 1.72, for a total of R 24.72. Hmmmm...better than my upstairs at r19. So my concern is that the de-humidifier will cause the basement to get hot. It will act as a small heater. Would it be better to put an airconditioner in the window? I have an office in the basement, and don't want it to get too hot in the summer. Thoughts?

Warren

Duhumidifiers do put out a fair amount of heat. The ones that are designed to work in cool basements put out more heat, I guess so they don't freeze up. Dehumidifiers work great for taking the chill out of a cool damp basement in the winter.

Small window a/c units work great for dehumidification. A 1400 sq ft rancher I had two years ago had humidity problems. The a/c system did not run long enough to effectively dehumidify; about 68 percent was the summertime average,inside the house. I put in a small energy star window shaker to try it out. The house settled in at about 58 percent after a few days running. The huge bonus was that it cooled the whole house and I quit using the central unit. I set it at 72 and let it run. Saved about 60 bucks a month in electric.

So Warren, I would suggest the smallest Energy Star window unit for the summer, and a dehumidifier for winter.

I have two dehumidifiers in storage, both kinda new. If anyone wants one and are around Northern Neck Virginia, your welcome to them.

 

[the_guad]

So, if your basement is cool and damp, would putting an AC in actually fix the problem? Since the room is already cool I'm not sure it would stay on unless you set it to a really cold level. Just a question, not a statement...

FYI: the Sears Kenmore large capacity models were rated very highly by Consumer Reports.

 

[velvetfoot]

Well, my solutions are below.
Please excuse the mess.

I used some 4' wide wood laminate foam underlayment I found at HD for the softener tank.
It is quite thin. Two layers didn't stop the condensation totally.
I wrapped the rest of the 25' roll ($25/roll) on it and will check it later today.
I wrapped the lower part of the well water pressure tank with 5 1/2" foam sill seal (again from HD).
I wrapped the pipes with foam insulation made for the job.
MANY tie wraps were used - my craftsmanship on the pipe turns isn't superb.
It is amazing though how much water is condensed by any exposed cool surface!

The dehumidifier is also going now.
The unit has a pump that empties the tank automatically when it gets full.
I set it at 70% - it started at 83%. What is the highest I can get away with, I wonder? I guess I will look into a psychometric (sp?) chart (cheap b-d emerging.)

I also closed the little basement window.
Of course, this will probably get the radon levels to go up and I'll be under pressure to do something about that!

http://velvetfoot.com/coppermine/thumbnails.php?album=6

 

[begreen]

I'm dealing with this problem in spades these days. See my post here in the green room titled Basement insulation. My take is that you need to use a dehumidifier once the house is built. If you would have put insulation and moisture control on the outside of the foundation, then your good to go. Otherwise, you need to control the humidity level inside. What I'm concerned about now is that once I get the basement insulated to my satisfaction (it will be at least r23 when done (r10 due to the insulpink, r 13 from the non-faced bat insulation (plus what ever a concrete block wall is...(r -2?)) seriously, probably r 1.72, for a total of R 24.72. Hmmmm...better than my upstairs at r19. So my concern is that the de-humidifier will cause the basement to get hot. It will act as a small heater. Would it be better to put an airconditioner in the window? I have an office in the basement, and don't want it to get too hot in the summer. Thoughts?

Warren

What is the ambient temp in the basement during summer? If it's say 75 degrees and the dewpoint is 75, there will be condensation, especially on surfaces that are even cooler. If AC would not work because it would not run often enough to remove excess humidity, then perhaps one could get rid of the excess heat created by the dehumidifier by venting it? Depending on its design and whether there is a convenient basement window, I don't see why the waste heat couldn't be ducted out the window. Worth a try with some ductape and cardboard as a test at least.

There are ductable whole house dehumidifiers. They cost more, but may be worth it for the lower maintenance and ductability. It will need a gravity drain or a condensate pump. Here is a link to one for under $1000:
(broken link removed to http://acforsale.com/online/product_info.php?cPath=34_35&products_id=2052)

Here is a commercial unit that will also handle the job. Pricey, (About $1700) but includes a condensate pump and more sophisticated humidity removal system. They use these on pool houses, etc. Both the intake air and exhaust are ductable.
(broken link removed to http://thermastor.com/pdf/HI_E_D2.pdf)
(broken link removed to http://acforsale.com/online/product_info.php?cPath=34_79&products_id=791)

 

[the_guad]

Velvetfoot, the common denominator in these threads is that everyone is using some type of electric climate control. I prefer a single use appliance like a dehumidifer over an AC if you don't need it. Good luck though.

 

[velvetfoot]

Thanks. It's still killing me to use it though.
The next step is to use it as little as possible.

I am thinking now, however, that the moisture I see on the bottom of some of the walls is actually condensation!

If I ever do insulate those walls, I would think long and hard about letting fiberglass anywhere near it. For sure, a real tight first layer of foam at least, or total foam, with some kind of paperless moisture resistant wall board. Perhaps when I am ready there'll be foam that is more fire code friendly.

 

[velvetfoot]

Well, it seems the moisture on the wall was indeed condensation, since it is gone now after a day of dehumidification set at 70%. In retrospect, the pattern was somewhat reminiscent of the condensation patterns on windows on a cold winter day. There still is a very small amount of condensation on cold water pipe that is still exposed, but I think I'll insulate that whole run. It is warmer down there now.

 

[the_guad]

70% relative humidity is still pretty high. Last time I checked the 50-60% area was suitable for human living areas whereas the 70% and above area was prone to condensation and mold growth, not to mention deterioration of condensing surfaces.

(broken link removed to http://www.epa.gov/mold/preventionandcontrol.html)

 

[velvetfoot]

You are probably right. I am doing some more research, and I said, I'm cheap.
The 70% setting and closing the little window to the outside has seemed to make a big difference on the condensation I am seeing though.

 

[Turner-n-Burner]

velvetfoot,
First off - close the window! in this weather ( not sure where you're located) the surest path for moisture to enter your basement is the humid outside air to come in that window. It meets the cool walls, floor, and plumbing and condenses... Been There Done That. So try closing the window first. Then, if you still need to, a dehumidifier is worth having.

I just replied to your radon thread as well - I have used radonseal, and I have very little moisture in my basement. I do have a dehumidifier, but it cycles rarely and that seems to be mostly from laundry activity and outside air coming in.

-Dan

 

[velvetfoot]

T&B: At 65% I'm not even getting condensation on the cold water pipes, near as I can tell. Alas the radon down there is now up to 7 (I have an electronic meter). The radon seal is very tempting. Preparation could be a chore (acid etching?), plus that stuff is not cheap.

 

[Sandor]

Velvet, seal up your basement before you deal with humidy or radon issues.

I does matter and it does work. Poured concrete walls are actually quite porous.

Also, deal with the outside of the house first. Hydronic pressure can be very high, forcing water and gases into your basement.