Dehumidifier In Damp Basement

[xroad]

I have a basement that is very humid. Some of the tools I have shows surface rust. I now have a dehumidifer running on a timer. It runs for an hour every 3 hours.

Here is what I have read, may or ay not be true.

1/ High water content in the air (most humid) may not be the most damaging to my tools or metal surface in the basement.

2/ Moisture stays in the air but condenses on cool surface. So, the most damaging time is when the air temperature drops and the cooler water content floating in the air looks for a cool surface to attach to.

3/ So,the critical time is to extract the water from the air is before the temperature drops, say late afternoon.

Does this all make sense?

 

[Stuart in MN]

I would think the temperature in the basement should remain fairly constant - it will change over time, but in the space of a day not that much. Have you actually seen condensation on the tools or other items?

Personally, I would just run the dehumidifier continuously - it should have a humidistat control that will turn it off if the humidity does drop below the set point. Another thing that may help is to set up a fan to circulate air in the basement, a cheap window fan on low speed would work.

 

[xroad]

My back door leads to stairs to go up to the kitchen or stairs to go down to the basement. The back door is the most used door so hot humid air from outside gets "mixed in" often. I have not seen moisture on the surfaces but I assume that is the cause of the surface rust.

My friends detached garage is well sealed and well insulated. When he opens the door and the humid air rushes into the cool garage, moisture immediately forms on all surfaces. He said it impacted his weak battery "border line" beater car as the moisture formed on the spark plug wires and all caused starting problem. SO ..... I imagine what is happening in my basement to a lesser degree.

 

[Tech Guy]

At this time of year I always run a de-humidifier in my basement. Cold air just naturally seeps down there from the rest of the house. I have closed off the ceiling vents down there for summer and whenever I run the fan or AC it does draw some of it out through the cold air return I have in the basement. Either way it still gets damp down there when its humid outside. I have never seen any condensation but the de-humidifier certainly pulls the moisture out. I usually have to empty it once a day

 

[xroad]

I know I am pulling lots of water out of the air. I use to empty the bucket couple of times a day. Now I connected a hose and run it to the sump pit.

I use to have an old dehumidifier that cycles on and off per my setting. Recent years, all the units I purchased would get trigger on and never stop until the bucket is full. Maybe the humidity sensor used these days are crappy to save cost? Who knows. I just put it on a timer to run an hour every 3 hours.

 

[aandpdan]

Pick up a hygrometer (humidity meter) and see what the humidity in your basement is at.

Any ferrous steel surface will rust over time, no matter what you do.

 

[lilredex]

We have a de-humidifier in the basement, but it has never been used. The furnace fan runs on continuous 24/7 all year around and the circulating air takes care of any humid smells that could develop there. A cold air return duct is also installed at floor level.

Running that fan motor (1/2 HP) probably adds $10 per billing period, but it is well worth it for the all season comfort.

If I shut off the fan, to say, go away for a few days it always smells like a root cellar in the basement upon our return, so I know my method is effective.

And, there is nothing rusting away down there either.

 

[tube_guy]

Like your friend is experiencing in his garage, the most damaging time is when the air temperature heats up suddenly, like if you open a basement or garage door and moist, warm air enters from outside. The temperature of all tools remains constant because they're heavy and remain at the colder temperature longer than the air, and then the moisture from the sudden burst of warm, humid air condenses on the cooler tools.

I run a dehumidifier in my basement continuously and I pull out a lot of water. For something really heavy, like a machine tool, you want to keep them a little bit warmer than the expected air temperature. That way no moisture from the air can condense on them. I usually rig up a few incandescent lightbulbs as heaters for situations like this. That and a really thin coating of oil works quite well.

 

[KCarGuy]

I have a Kenmore Dehumidifier that I have used for 30 years now.
I Forget the specs, but it has a 2 Gallon "Fill Bucket" that can be used...or...a hose can be attached to the bucket (which I use) and the water drains into a floor drain.

I have it set to run Constant, but run the Humistat at "5"
The switch goes from "Off"...1-6.

In the summer, my Basement feels 20 Degrees cooler...simply because it is cooler and its drier than the Upstairs.

 

[spongerich]

I leave mine on all the time. I have the dial set around halfway.
During the summer it runs about 70% of the time. During winter, hardly at all.

Don't seem to have any problems with mold or rust. Before I had the drain hose hooked up to it, I'd need to empty it daily or more.

 

[mhm993]

Same as everyone else: Run it all day on a middle setting. Put the hose in the sump. Keeps the basement cool feeling and bone dry.

 

[Jackfre]

An alternative is the Tjernlund Xchanger. It comes pre-wired with a humidistat. Costs much less to run than a dehumidifier.

 

[jordan369]

I have a GE dehumidifier I bought at Sams Club. I set it to 50% humidity on the digital controls and it cycles on and off as needed throughout the year. I have it hooked to the floor drain with a hose. A light comes on when the air filter needs cleaned but other than that its maintenance free and my basement is mold free.

Mike

 

[xroad]

I usually rig up a few incandescent lightbulbs as heaters for situations like this. That and a really thin coating of oil works quite well.

Speaking of light bulbs. One of my friend have a dirt floor garage to park his motorcycle. He keeps the bike cover with a waterproof cover and keeps an incandescent bulb under the bike to keep warm air raising into the bike cover.

 

[General Lee]

I also run a dehumidifier in the basement from May to about October. Its a 70 pint capacity and I have to empty it once a day. I have no where to run a hose for the automatic drain.

 

[aandpdan]

I also run a dehumidifier in the basement from May to about October. Its a 70 pint capacity and I have to empty it once a day. I have no where to run a hose for the automatic drain.

I did that for years. It gets old after a while lugging the pan upstairs to dump.

You can pick up a condensate pump, or if your furnace has one tap into it too. Then you can direct the water anywhere you want, even pump it upstairs to a drain if you have to.

 

[General Lee]

I did that for years. It gets old after a while lugging the pan upstairs to dump.

You can pick up a condensate pump, or if your furnace has one tap into it too. Then you can direct the water anywhere you want, even pump it upstairs to a drain if you have to.

Fortunately, I have a door in my basement so dumping it is quick and easy but still a PITA. You just made a good point.....I do have a condensate pump in the basement for the HVAC. I'll have to check it out and see if it has another port where I can run a hose into it. One issue though, its mounted off the floor about 8'', so not sure if the gravity flow from the dehumidifier could get the water in the pump. I'm pretty sure the dehumidifier is gravity fed drain and not forced pumped but I'm not sure.

 

[xroad]

Fortunately, I have a door in my basement so dumping it is quick and easy but still a PITA. You just made a good point.....I do have a condensate pump in the basement for the HVAC. I'll have to check it out and see if it has another port where I can run a hose into it. One issue though, its mounted off the floor about 8'', so not sure if the gravity flow from the dehumidifier could get the water in the pump. I'm pretty sure the dehumidifier is gravity fed drain and not forced pumped but I'm not sure.

Ehhh ... I can help with that one. From experience, I ran a very long small diameter tubing from the dehumidifier to the sump pit. Problem is the LONG thin tubing presents sufficient resistance (drag) to not allow the water to flow. The potential pressure (height) is not enough. I propped the dehumidifier up on a milk crate and it worked reliably. Sorry this rambling and I still have not got to your problem ..... If you have any window in your basement, you can mount the dehumidifier from the ceiling, as high as you can to create maximum potential pressure and run a hose out the window. If there isn't enough pressure to overcome the hose resistance, use a bigger hose. Most hose connection to the water catch box are of garden hose connection. You can get a short length and hang it along the wall to get to the window. Garden hose will have NO resistance. All you need is a tiny pitch between the unit and window.

 

[xroad]

I don't think circulating the air would help unless you are pulling in dry air to dilute the moist air. Otherwise, you'll be coating all surfaces evenly with what ever moisture there are in the room. If the outside air is more humid ..... even worst. Most of my humid air comes from the side door to the house (the most used door). The door leads up to the kitchen, which have a door, and down to the basement, which have no door.

 

[ptschram]

I've dealt with this for more than 40 years at my old house.

First off, make sure you don't have any ground water making its way into the house. Our basement was dry until the city came by and bricked up the downspouts when I was a little boy. Instantly had water in the basement.

Went through many dehumidifiers. When we attached a hose to drain them constantly, the dehumidifiers began to wear out prematurely.

I have since become a huge fan of ventilation-especially if the basement is occupied for any length of time as Radon will only become more of a problem as we seal our houses up.

It shouldn't take much of a fan to move enough air to keep the humidity down and small fans shouldn't' cost much to run compared to a dehumidifier.

 

[ultgar]

I tried the fan solution for our damp crawl space in Charlotte.....didnt work at all considering the air I was pulling in from outside was already 70-80% RH.

Ended up encapsulating the space and running a Santa Fe Compact 2 dehumidifier. Now the space stays around 43-45% during the summer months. I'm using the same dehumidifiers in my NJ basement office.

SD

 

[jabin]

I don't think circulating the air would help unless you are pulling in dry air to dilute the moist air. Otherwise, you'll be coating all surfaces evenly with what ever moisture there are in the room. If the outside air is more humid ..... even worst. Most of my humid air comes from the side door to the house (the most used door). The door leads up to the kitchen, which have a door, and down to the basement, which have no door.

My basement door situation is the same, our back door opens to a landing, down to basement, up thru. a door to the kitchen. I have a creek behind my house and a river 200 yrds away. In Ohio it can get humid in the summer. I have my dehumidifier set at 55% and it runs very often but it doesn't smell anymore and my tools and 44" HF cabinet have no rust, it stays dry.

First thing you can do is run yours more often and see if it makes a difference.

 

[PsRumors]

What are the dimensions of your basement? A Sante-Fe dehumidifier of the correct size will do wonders.

Our crawls space and attached garage was always humid and smelly, sealed all vents and air leaks, covered the grown of the crawlspace and added a Sante-Fe Advanced 2 and humidity is being held at 48%. Prior it would be upwards of 67%.

You need a dehumidifier with a humidistat to run based on the humidity, running on a timer is not the way to attach this. The cost for us is less than $25 a month

http://www.santa-fe-products.com/product-solution/

 

[Retlaw 66]

....
2/ Moisture stays in the air but condenses on cool surface. So, the most damaging time is when the air temperature drops and the cooler water content floating in the air looks for a cool surface to attach to.
.....

Yes, moisture will condense on a cooler surface.
But the worst time is when warm, humid air enters a cool basement.... the moisture will condense out of the air and onto all cooler surfaces.... tools, equipment, even walls and floors.

If you are ventilating, you don't want to pull warm humid air into a cool space. Better to keep it somewhat sealed off in those conditions.

I have a pair of dehumidifiers running in my basement workshop set at 55%. They pretty much only run during the summer.