Basement humidity

[zdech123]

We have a new construction home in southern Ohio with an unfinished basement. We are storing some stuff down there and a few pieces of furniture. Some of the furniture is particle/ikea "wood". We have a dehumidifier and if we set it to 75% humidity in about 4 fats we have almost 3 gallons of water. It did not feel damp down there but after 2 weeks of emptying the dehumidifier 3 times I was amazed. The basement is extremely dry now, you can taste it.
I have since turned the dehumidifier off since it is getting cool and not that humid. Is there a time of the year I should turn it on/off? A certain percentage to run it? I am not sure if the wood in the basement/the wood holding the house together that is, or the basement concrete needs some sort of moisture?
Any help would be appreciated. Thanks

 

[d.mcfarland]

In the basement if you are using it to store stuff that could be damaged it would be best to obviously use it year round. Use the feature so that the machine cycles on and off for the longest possible life of the dehumidifier. 75% might be a little high so you might be able to go lower, but I'm no expert.

 

[chruler]

I would just leave the dehumidifier on. It will work when it needs to, and shut off when it's not needed. Humidity damages a lot of stuff. Just ask my guitars!

 

[padroo]

I wouldn't go much higher than 55%.

If you can connect a garden hose to it and get it to a sump pump pit it wouldn't be such a pain all the time.

 

[Doug19]

You'll want to cover up you sump pump area the best you can otherwise you are just wasting electric. I run my full time at 45%. It runs now and then in the winter and pretty much full time in the summer.

 

[LifeLongWNYer]

My cellar has a partial concrete floor and partial dirt floor, under a house built in the 1880's. My dehumidifier runs 24/7/365 and won't take the humidity below 65% in the summer, 55% in the winter.

The condensate runs into a "condensate pump" which has a small sump, which is automatically pumped into a drain to the septic tank.

I can't leave anything metal down there without it growing surface rust.

Anybody have an answer for this?



JBP

.

 

[gregtwojeeps]

Agree with all. Set your unit at 55% max to run year round ... 45-50 % RH in a home is desirable. Excess humidity in a home is not good. If you do not have a sump pump to run it to..... turn greenie and get wild on it ...

Set the humidifier up on a stand and let it drain in to a sealed five gallon bucket. Then you have free water for indoor house plants, or outdoor flowers or to just wash muddy boots or tires off. JMO

 

[garrett1812]

First, get a dehumidifier with a drain line and run to a drain or sump pit. Will save a ton of hassle.

Second, do you have any hvac vents in the basement. That is how our new construction home with a basement is. It's merly two vents cut into the trunk that feeds the first floor. It won't condition the space, but a little air exchange goes a long way.

 

[garrett1812]

My cellar has a partial concrete floor and partial dirt floor, under a house built in the 1880's. My dehumidifier runs 24/7/365 and won't take the humidity below 65% in the summer, 55% in the winter.

The condensate runs into a "condensate pump" which has a small sump, which is automatically pumped into a drain to the septic tank.

I can't leave anything metal down there without it growing surface rust.

Anybody have an answer for this?



JBP

.

Maybe put plastic over the dirt? Huge moisture supply there.

 

[zdech123]

The dehumidifier does have a line to run a hose off of. I attached a hose and ran it to the sump hole, just haven't turned it back on yet. This will obviously take care of the bucket filling issue, I just wasn't sure if I should have it on all year or at what percent. I will set it to 50%.
Question, is the higher percent more moist or more dry? If it is set at 75% does that mean it runs more or less to take out the moisture? Just wondering.

Thanks again guys.

 

[sledneck32!]

The dehumidifier does have a line to run a hose off of. I attached a hose and ran it to the sump hole, just haven't turned it back on yet. This will obviously take care of the bucket filling issue, I just wasn't sure if I should have it on all year or at what percent. I will set it to 50%.
Question, is the higher percent more moist or more dry? If it is set at 75% does that mean it runs more or less to take out the moisture? Just wondering.

Thanks again guys.

Higher number means more water in the air.

Sent from my LG-H811 using Tapatalk

 

[Stuey]

The dehumidifier does have a line to run a hose off of. I attached a hose and ran it to the sump hole, just haven't turned it back on yet. This will obviously take care of the bucket filling issue, I just wasn't sure if I should have it on all year or at what percent. I will set it to 50%.
Question, is the higher percent more moist or more dry? If it is set at 75% does that mean it runs more or less to take out the moisture? Just wondering.

Thanks again guys.

The higher the number, the higher the humidity and moisture content of the air.

Set the number lower to remove more moisture.

It works kind of in the same way a thermostat. Set it to say 55%, and the dehumidifier will aim to reach that humidity level. If it's 60%, then it'll keep running if or until it reaches 55%. If it's 50%, it'll shut off and will remain off until you change the setting or humidity rises above 55%.

 

[larry4406]

You say you have two hvac supply registers in the basement; make sure they are open.

Do you have an HVAC return in the basement as well? In the houses my company builds we put the units in the basement and even with unfinished basements, we have a return at the unit cut directly into the return box.

 

[captain14]

How much will the heating season do to remove the humidity in the basement? No outlets or returns in my basement .
Block walls and concrete floors .

 

[pjboy]

can you get one drop or small; return down their,wheres your heating unit? a fan pushing air to return will help.

 

[matt_i]

If you have exposed dirt, the only way is to install a vapor barrier to "seal" (within reason) the moisture into the soil.

Otherwise the humidifier will be working like crazy to remove water vapor.

I had an old house in Tennessee with exposed dirt crawlspace. Very damp and the house smelled musty always. I installed a plastic vapor barrier, with the intent of clamping it between treated 1x2s screwed to the concrete walls of the crawlspace. I never completed the 1x2s but even with the dehumidifier working against the imperfect sealing, the smell went away within 2 days, a very big change that everyone noticed. I went the route of attaching the hose, running it under the wall footer and into an ABS tube, down into the yard several feet, all downhill, pouring out thru a grate at the end.

There are better quality dehumidifiers which last longer and cost more, like in the $700+ range. I expected to buy another Big Box offering in 2-3 years but I didn't live there long enough to cross that bridge.

 

[Showkey]

Agree with the others 50% is a good goal. 70-75% is way too high. At 70% bad things can start to happen......musty smell, organic material like paper, leather particle board and cotton may start to mold etc. I was at this point in an out side shop that was well insulated and sealed. The humidity level has at 70-75%. Added a large dehumidifier and the water that came out was substantial this was 1000 sq. ft. It has slowed but the unit is needed. If you have a large space you may need a more than one unit. Buy a dehumidifier that is rated for low temps ( 41* is the standard for low temp) ..........cheaper units the coils can freeze up at normal basement temperatures.

OP how new is new construction ? New materials like wood, dry wall, paint and concrete may be adding to the moisure levels. Moisure ( ground) migrating through and out of the concrete floor can add to the problem.

One check........tape aluminum foil square to the concrete floor ( completely sealed ) let it sit a day or two. Lift the patch and check for moisure.

After the concrete cures the walls can be painted with moisure sealing paint to slow moisure migrating through.

 

[Jackfre]

I built a wall bracket and set the de-hu up on it. It was high enough to drain into the stand pipe for the washing machine. If you can't get to a drain at least build a stand for it where you can put a 5 gal pail under it. Even on the stand I would occasionally put the drain into a bucket just to see how much I was collecting.

 

[buddyboy]

another thing you might consider doing:

in my basement i set the dehumidifier at 55%, in the summer it runs and never shuts off, about the end of september it shuts off and hardly ever turns back on until May. I have a garden hose attached to it, draining into a floor drain.

I have a rather large basement and I put two oscillating fans, apart from one another, on timers. they run 15 minutes then off for 1hr 45minutes, i have them run at different times.

this is just for air circulation.

I run the AC all summer too, but that is for just the living space upstairs, I have one or two vents that dump conditioned air into the basement.

between the dehumidifier, fans and AC it keeps my basement smelling fresh and dry.

 

[zdech123]

Agree with the others 50% is a good goal. 70-75% is way too high. At 70% bad things can start to happen......musty smell, organic material like paper, leather particle board and cotton may start to mold etc. I was at this point in an out side shop that was well insulated and sealed. The humidity level has at 70-75%. Added a large dehumidifier and the water that came out was substantial this was 1000 sq. ft. It has slowed but the unit is needed. If you have a large space you may need a more than one unit. Buy a dehumidifier that is rated for low temps ( 41* is the standard for low temp) ..........cheaper units the coils can freeze up at normal basement temperatures.

OP how new is new construction ? New materials like wood, dry wall, paint and concrete may be adding to the moisure levels. Moisure ( ground) migrating through and out of the concrete floor can add to the problem.

One check........tape aluminum foil square to the concrete floor ( completely sealed ) let it sit a day or two. Lift the patch and check for moisure.

After the concrete cures the walls can be painted with moisure sealing paint to slow moisure migrating through.

New construction as in we moved in a month ago. Basement has been poured for about 6 months. There are hvac vents in the basement and insulation on the walls. I have a box fan that I could put on a timer too.
Is being too dry a problem? Other than wearing out the dehumidifier and running up an electric bill?

 

[engineer2]

I have all of these in my basement and have never needed a dehumidifier.
Water barrier coating on the outside of the foundation (looks like tar)
All concrete joints, cracks, seams caulked
Floor paint that blocks moisture
Perimeter foundation drain with sump pump (not needed in all parts of the country)
Air circulation (keep in mind no air returns allowed in same room as gas heating equipment)
Source of heat in the cooler seasons

 

[Showkey]

^^^^^^^^^^^^^^
That is possible. Especially if there is no living space with carpet and furniture etc
40-65 % is rarely an issue. 70-80% things get iffy. Above 90% would be like a rain forest and green and black stuff would growing on the walls.


If there is sand a gravel in the area it drains better.........BUT..........the humidity issue also comes from the warm moist outside air and generally cool temps in a well insulated basement that cause the issue when the air masses meet. But zero or low air exchange rate can make for a stuffy stale basement.

You and others think you do not need humidity control but unless you measure it often your nose might NOT be telling you the truth. Since you sign is engineer2 I would guess you would be measuring the temps and humidity levels.

Running AC in the whole house during the summer maybe all thats needed.
Few run dehumidifiers during the heating season......and .........often people run a humidifier to add moisture.

 

[engineer2]

Yes, temp was and humidity were measure to be about the same as the main floor. A major help was the subfloor heat. This is supplemented with small ceiling registers above the basement windows and a good size air return. I run the subfloor heat on a programmable thermostat and leave it on year round, but it rarely runs in the summertime. I think it also helps that the foundation is pretty well sealed. Never had a drop of seepage and our soil around here is wet 2 feet down.

 

[MushCreek]

I check mine often with a hygrometer. Here in SC, it's pretty humid. Our house is also new, poured about 3 years ago now, and the humidity levels have been gradually dropping. I run a dehumidifier about 2 days a week now in the summer. If you have any outside air entering the basement, humidity will always be a problem. The hot, humid outside air hits the cool concrete and results in condensation, like a cold drink on a hot day. No amount of sealing will prevent this, but limiting the outside air helps.

 

[gregtwojeeps]

I had crawl space water issues and have corrected them with sump pumps/re-grading hopefully. I also installed a dehumidifier in the CS....

So as a maintenance program and to keep me from having to go under the house to check the state of humidity....I bought this unit and put the master in my den on my PC desk and the sensor in the crawl space.....

http://www.lowes.com/ProductDisplay?productId=1075631

Works great, I can read the CS humidity level at any time, rain or shine... plus I can keep an eye on the CS temp and be sure my pipes in the CS don't freeze. A win/win tool for cheap. JMO

 

[pop pop]

Anybody recommend a dehumidifier? I can't get one to last more than two years.