basement humidity

Good question, would like to know myself.

Garrett76 posted:

For all the people with layouts in the basement or garages, what lessons learned do you have when it comes to humidity levels?  Any specific guidance on a humidity % to maintain below or above?  Impact of straying beyond those thresholds?

Thanks

Two thoughts:

1) Much depends on your location, i.e. local weather conditions.

2) Try and keep it as try as possible. Low humidity is VERY good.

GARRETT76,

  Here in New York, this will sound like I am a hostage, but I think you will get it...I've been in the basement for the last 20 years and rarely run the dehumidifier. 

  This topic comes up every so often, you may want to use the search area and scroll through the topics.

Tom 

Here in western Mass, I have my dehumidifier going 24/7.  I keep it at 50% humidity.   I would go lower but the electric cost would not be worth it.

I’m in the Atlanta area and discontinued use of a dehumidifier in our basement.  We are fortunate to have a dry basement to begin with plus, I discovered not having enough humidity in the air negatively impacted operation of some accessories such as the 464 saw mill.

Curt

Air exchange is key for many reasons. I have a high cfm fan mounted in a window that pulls air FROM the basement to outside. This helps on a number of fronts....humidity one of them. I read all I could on the subject and exchanging the air is important. My fan runs on a timer and is turned on the first ten minutes every hour April to Sept. I can get a few days were the humidity gets higher than I like,,,,I switch on the fan for a hour or so. 

I live in the Ohio Valley area of Kentucky and keep my basement humidifier set in dry.

Haven't checked the actual humidity level 🤔

I have an issue with dust though so I may be keeping it to dry .

I run a dehumidifier spring, summer and fall and can keep it between 50 and 60% and have had no issues.

My dehumidifier is set at 50, and in the summer it runs nearly all the time. I have to believe the trains would suffer without it, and I know I would.

Well, my basement leaks. I have good drains and the floor slopes down to them. I take every precaution to keep anything that wood absorb moisture off of the floor. So my benchwork legs all have metal feet adjusted to be an inch or so of of the floor. I can't have any carpet so I use those childrens' playground foam squares that lock together. When it rains and the basement leaks, I take them up until it dries. I use a dehumidifier set to 50% and it is on 24x7. Plus I am of course careful not to store anything on the floor that could get wet--like cardboard boxes. The long term effects of all this moisture on the layout can't be good. But there is no choice. And so far things are okay.

Don

Maryland. Finished basement. 50% setting.  You can’t believe the amount of water they is taken out of the air over several days. Dehumidifier is great investment for basement trains. 

MNCW posted:

GARRETT76,

  Here in New York, this will sound like I am a hostage, but I think you will get it...I've been in the basement for the last 20 years and rarely run the dehumidifier. 

  This topic comes up every so often, you may want to use the search area and scroll through the topics.

Tom 

it puts the lotion on

I set the dehumidifier to 50%, no issue with rusting buildup on Gargraves tinplate track , furnace ductwork or copper water tubing, the humidifier operates approximately from late April through November, location Northern Indiana.  

The good news is that you can buy a dehumidifier for about $140 (Amazon--HomeLabs) that will handle up to a 2000 sq ft area.  If you have a sump crock or french drains you can continuously drain it into these if you have high humidity.  I keep ours at about 45%, which seems about right.  Mostly a summer problem, despite the central A/C.  In winter it's dry on the North Coast .

I live in an older house about an hour North of the Twin Cities in MN.  I have a dehumidifier in my basement which is left on year round.  During Spring and Summer I hear it run frequently, during Fall not so much and never during Winter.  When I first moved in it had a tank that needed to be emptied daily if not every 1.5 days.  Got a newer model that had a hose attachment and the hose runs to a floor drain.  No more emptying.  It's set at 60% because, like the example above, any lower and it would just be on all the time.

Even so, with some of the heavier rain we've had recently I've had wet floors and time that it needed to dry out.  I'm not inclined to put my layout in the basement.  Just getting restarted, not sure where it'll go yet.

Garrett76 posted:

MNCW posted:

GARRETT76,

  Here in New York, this will sound like I am a hostage, but I think you will get it...I've been in the basement for the last 20 years and rarely run the dehumidifier. 

  This topic comes up every so often, you may want to use the search area and scroll through the topics.

Tom 

it puts the lotion on

......… or it gets the hose.

Here in central PA, my dehumidifier is turned on from late April to mid-October.  It keeps the basement at 60% humidity.  No rust on anything.

I have a dehumidifier and I have found that 50-55% humidity works fine, really anything 60 or below should work well. My basement itself is dry (has a french drain system that works well) but being below grade still can get humid. 

The alternative is to use venting. Running a fan with external venting works because it creates negative pressure in the basement which sucks drier air from the rest of the house (the ads you see for the "wave ventillation system" they advertise is basically nothing more than a bathroom vent blower with a humidistat that kicks in when it reaches the target humidity level. They also put a grate on the floor above the basement that allows air flow down and out based on the negative pressure). 

You do need to be careful with this approach if you run it a lot. Negative pressure if you have a gas hot water heater or a furnace can potentially suck CO back into the room (especially hot water heaters, they don't vent well to start with), it is a concern. 

A better way (more expensive) is a ventilation system with an air to air heat exchanger, where it vents out the air from the basement to outside while drawing in fresh air from outside, it heats/cools the incoming air with the air it is sending out from the house (in summer, when it is humid out, the cooler air going out will cause the moisture in the incoming hot, humid air to condense and be drained from what i understand). Because it exchanges air with outside air, there is no negative pressure created, you do lose some heating/cooling by exchanging air, from what I have seen you lose around 10% of the heated/cooled air this way in the sense that the temperature goes down/up a bit with the new air in winter/summer. 

The dehumidifier is the simpler option, draws more power than either of the two approaches above and doesn't refresh the air, but does drop the humidity. 

Not the original poster but thanks all that responded with input. I thought it was a good/interesting question. Being in Ottawa where we swing from mid +40 to -40c between seasons  I should probably pay attention to this. 

That being said, usually keep the house at 40-50% humidity due to hardwood floors, basement, (where under construction layout is) is generally about 50-60% on really bad days, (+48c).

"Best" for climate is very regional. A local pro has your best answer on how.

Low humidity is great, but in my experience; over time, morning beams of sunlight moving across a cool room is the worst offender. Even low humidity air conditioned rooms can have issues with this.

  Light can almost instantly heat just the pocket of air around the nice cool metal enough to cause condesation, and with it, some rust. Often beams can be fast moving and the metal doesnt heat much at all and the rust will be heavier there. Good airflow circulation within an area helps, not necessarily recirculation or fresh, but good air movement to promote consistant air temps vs pockets of warm/cool.

Yes humidifier in the basement is a must. I set mine at 45%.  It ususally shuts off in December and comes back on in March or April depending on the thaw here in this far south suburb of Chicago.

A dehumidifier also has a warming effect on the basement during those damp and rainy 50 degree days in the spring and fall.

If its feasible for your situation. I highly recommend concrete floor paint for the floor and Drylock paint for the walls.

This makes the dehumidifiers job much easier by sealing the pores of the concrete which can breath ground moisture into your basement.

This also helps minimize the infinite concrete dust emitted by bare concrete.

I'm living here in Allentown (you can finish the song) and have a dehumidifier set at 50%. Without it it would soar to well over 60%. Rather than empty the unit each night I have it drain into a tub with a sump which then directs the water to the drain. Works great.

Southeast PA.

I run (3) of them in my basement. One is in a 12x12 storage room, the other in my 6x25 utility room and then the 3rd in my 25x32 train room. Usually just keep them on all year but usually stop running around October - March.

All set to 50% and only the one in the train seems to run 24/7. That ones drains into a floor drain with a backflow limiting device installed.

My basement is a great place to work, perfect humidity and a constant 68 to 70 degrees.

I design power plants for a living so it is a moot point about the electric bill. I would rather pay that than be unemployed!

Donald

Just a note: if you desire automatic draining of your dehumidifier and you are below any nearby drains, you may purchase a small condensate pump and pump it up to almost any height.  They are small, cheap to run and very simple to install.  I use one to raise condensate water up to the height of a nearby drain for the backwash of my water purifier. A clothes washer drain will work or just plumb it outside.Iit uses small clear plastic hose for drainage.   Just google it and you will find hose and fittings as well.  

RickO posted:

Yes humidifier in the basement is a must. I set mine at 45%.  It ususally shuts off in December and comes back on in March or April depending on the thaw here in this far south suburb of Chicago.

A dehumidifier also has a warming effect on the basement during those damp and rainy 50 degree days in the spring and fall.

If its feasible for your situation. I highly recommend concrete floor paint for the floor and Drylock paint for the walls.

This makes the dehumidifiers job much easier by sealing the pores of the concrete which can breath ground moisture into your basement.

This also helps minimize the infinite concrete dust emitted by bare concrete.

I second this- a dehumidifier is absolutely needed, trains or not

I run a dehumidifier 24/7 in the basement. I keep it at 45rh. 

I have a Frigidaire dehumidifier in my (finished) basement train room. It is set at 45% and is left to cycle on and off as necessary. Drains into a floor drain so no dumping of water from the unit is needed. I also have a fan running continuously in the foyer area of the basement (separate from the train room) during hot/humid days. The fan is pointed up the stairway to keep the basement from getting too cool. I found that when the central air for the house is running, the basement tends to get a bit too cold on hot summer days and this fan helps to force some of the cool air upstairs to keep things at a more comfortable level. I also had all the basement walls painted with Drylock and French drains installed before the train room was framed and drywalled. No problems thus far and the train room is quite comfortable, as is the equal-size lounge area adjacent to the train room.

That lounge area houses a wall-mounted TV, wall-mounted train display cases, a leather sofa, recliner, desk, dining room table, and several glass-door barrister bookcases which are also used for train display. Eventually hope to have a microwave, coffee maker, popcorn popper, and a small refrigerator in that area.

Basements are generally damp or even wet.  Dehumidification is a must, but things can be even better if you combine it with supplemental dry heat.  I run an oil filled electric heater year round and a dehumidifier from late March to mid October.  I set the heater at a 750 watt setting (It has 950 and 1500 watt settings).  I also set it to maintain a 72 degree temperature in the train room.  The dehumidifier is not in the train room but at the opposite side of the basement about 45 feet away.  It is always set for 45% RH.  It has an internal pump that empties the tank automatically.  

So, why do I run a heater and a dehumidifier?  Raising the temperature in the basement causes it to feel much more comfortable and helps the dehumidifier not to work as hard.  The walls and floors are drier and there is never a clamy feel in the basement.  

Also, under each side of the layout, I have a utility fan that runs twice a day for fifteen minutes just to circulate the air under the benchwork.  This helps to wick any moisture off the concrete basement floor and eliminate any possibility of a musty smell developing.  In the train room, I have a raised floor made up of RaceDeck floor tiles.  They are made of a very heavy plastic material and sit upon rubber cushions installed on the underside of each tile.   

The basement is ALWAYS comfortable, and the humidity has NEVER  been a problem.  I also have a wood shop in the basement and never experience warped or twisted wood stored down there.

Thanks to all.  I do have a dehumidifier and french drains.  Even in the torrential rain along the Atlantic, the basement has remained dry.  I was concerned about the long term effects of basement humidity on trains, modern electronics, and operating accessories that would be imperceptible day to day.  Sounds like many forum members have no problems with their gear so I consider layout building in the basement to be a manageable risk.

Thanks

I'm actually thinking of adding a dehumidifier to my finished basement where my layout is located, but will need one with an internal pump to get it to flow to a nearby sink.

I'm a little concerned about noise levels and how loud these units get, especially if trying to watch tv, listen to music, etc.

Are there some brands that are quieter than others ?

I have a Frigidaire unit mostly plastic body and bucket. Vibration is extremely noisy and irritating. I hate it. I have to place a block of wood under the bucket portion to at least make the noise tolerable. 

The basement dehumidifier is set to 45-50% and operates automatically throughout the year to keep that level. Here in Pennsylvania's SE Delaware Valley, it's most active from mid June to early October.

Richie C. posted:

I'm actually thinking of adding a dehumidifier to my finished basement where my layout is located, but will need one with an internal pump to get it to flow to a nearby sink.

I'm a little concerned about noise levels and how loud these units get, especially if trying to watch tv, listen to music, etc.

Are there some brands that are quieter than others ?

Yes, there are differences, but the COMMON  characteristic is that they are all noisy.  You can not avoid it.  There is a fan and a compressor.   Of the two components, the fans the biggest culprit in the noise wars.  If you can keep it in another room, you will be happier.  Humidity levels will be lower throughout the entire basement as long as you don't completely isolate the rooming question from the area where the dehumidifier is located.  If you have a room like a train room or TV room and there are doors, just keep them open during the season when dampness is at it's worst.  As long as there are currents of air humidity will be removed from the entire space ultimately.  

If you have a forced air heating and air conditioning system, I can offer a suggestion to help out you entire house maintain a more even heat, AC and ventilation throughout the entire house.

How wet/damp are your guys basements getting? I have a house built in 1956. The basement has tile over the concrete floor but no drywall (you can see the brick). It's about about 4 feet below ground (9 foot ceilings as the basement extends above ground level, common in Chicago). It has forced air heat/air conditioning. Basement is about 65°-75° all year with 50%-60% humidity (like the rest of the house). I have no rust issues. Track/wheels on the trains never rust. Heck I left some bare sheet metal from a project down in the basement for a month and it never even got surface rust. I figure as long as basement conditions are close to the rest of the house a dehumidifier is a waste of money. 50%-60% humidity shouldn't make your trains rust. Plus at that level static electricity is limited, which is a plus around electronics. 

Sounds like what I thought about the noise being an issue. I have forced hot water, so no whole house cure.

If I decide to invest in one, I'll have them turn it on in the store so I can gauge how loud it is.

Thanks.

Lou1985, you're a lucky man. 50-60% is good. No need for a dehumidifier. 

If one were going to install drains in a basement -- are French drains preferred over-- let's say German or English drains?

;-)

Lou1985 posted:

How wet/damp are your guys basements getting? I have a house built in 1956. The basement has tile over the concrete floor but no drywall (you can see the brick). It's about about 4 feet below ground (9 foot ceilings as the basement extends above ground level, common in Chicago). It has forced air heat/air conditioning. Basement is about 65°-75° all year with 50%-60% humidity (like the rest of the house). I have no rust issues. Track/wheels on the trains never rust. Heck I left some bare sheet metal from a project down in the basement for a month and it never even got surface rust. I figure as long as basement conditions are close to the rest of the house a dehumidifier is a waste of money. 50%-60% humidity shouldn't make your trains rust. Plus at that level static electricity is limited, which is a plus around electronics. 

A couple of comments (not about the post per se, but about humidity/what works on it)

1)basement humidity is dependent on a number of factors, one of the big ones is the nature of the property the house is on. Below grade rooms tend to have more humidity then the rest of the house (moist air, among other things, kind of tends to sink to the lowest level), but also a lot of people (like myself) live in places with high water tables, and that can cause moisture to seep into the basement. 

2)In many houses, the basement is not heated or cooled. In the case of the poster I quoted, they have forced hot air in the basement and a/c, and that is likely why the basement is kept in that range. Force hot air heat, as I know only too well, dries out the air (the furnaces put out water, that is sent to drains), in winter my house if I didn't have humidifiers would be like 25-30%. Likewise, air conditioners don't just cool the air, they also dehumidify it (many room air conditioners have a de-humidifier mode that basically mimics what a dehumidifier does). When the air is cooled down in the A/C it can hold less humidity, and the water condenses out of the air (ever look at a window a/c, with the water dripping out? Condensation from the air. So basically the heat and a/c are doing what a dehumidifier would do. 

50-60% humidity is fine, but few basements will keep that without some method of dehumidification or bringing in drier air, whether it is a dehumidifier, am air exchanger that brings down drier air from the rest of the house, or an hvac system working there.  In winter I don't have to run my dehumidifier, between the lower temperatures and likely the drying of the air from the heat in the rest of the house, it stays around 50%, I only have trouble when it warms up in the spring-summer-early fall months. 

I installed a mini-split heat pump in my train room about 18 months ago. It provides both heating and cooling, and it also has a "dry" setting. That setting will keep the humidity at around 50% but it makes the room too cold. The cooling setting keeps a steady temperature wherever I set it, but the humidity level is too high. So, during the summer months, I set it in cooling mode and also run the dehumidifier, and it keeps the room at a comfortable 50% humidity and 70 degrees. 

John