I can't comment, I'm busy thinking about whether or not I'm going to stay on Pinside, and why....

I have a humidifier in my basement that struggles to keep my humidity just below 50%. It’s set for continuous.

Bad thing is they last about fifteen months, just outside of the manufacturers warranty. They are a bear to get rid of, cause you have to certify they are empty of Freon. Around here, you need a license to certify.

I have an AC in my game room but use a backup dehumidifier to keep the humidly level below 70 percent. In Louisiana, I can't hope to get the humidity much lower than that.

Looking at your question again, my set point is 50%, and since humidity usually runs in the seventies during the summer, it’s always running. During the fall when humidity drops, it does cycle off.

Mine are also in a finished basement but we have central air, I've never used the small dehumidifier that we own.

You say yours are in a finished basement too - no a/c?

I have my de-humidifier set to 35%, it runs most of the time this time of year but is able to maintain the humidity level within 5%. I just checked my basement thermostat and its reading 70 degrees and 35% humidity...not bad for an unfinished basement.

Finished basement so I have A/C down there. However, the basement is on a separate zone. Even though it is a walkout, the A/C doesn't need to be active for that zone very often to keep it at temp. It can get humid down there, so I decided to get a dehumidifier. When I asked my HVAC guy about it, he told me to just get one of the portable ones. (I always love recommendations where you are told, in essence, 'don't pay me, do this instead'.) Anyhow, I have it set to 50%. Summers in the South can be a tad humid so it cycles on and off fairly often but does not run continuously.

I have central ac in my house, basment walls and ceiling are finished no flooring. I run a dehumidifier all summer at 45% sometimes it cycles off. If I dont run it even with the central air it can get above 70%.

My old dehumidifier was working fine.... or so I thought. Bought a newer one so I could run 2, it uses less power and pulls out 4x the amount of water.
Tossed the old one, bought a second new one.

Whatever you decide, please don't start a whole new thread about it.

I have opposite problem living in N CA. Mine are in partially finished and mostly sealed garage, but still park one car in other side of garage. Summers no problem, winter get fog creeping when door opened and rainy days are high humidity. Keep a dehumidifier running all winter on 60% and does pretty well. Mostly runs for a while after garage door is opened and closed.

Hey, there are no finished basements in Gloucester! I’m calling shenanigans!

lol

I have a finished gameroom with heat and ac. The ac helps dry the air out while running working as a dehumidifier. I also have a dehumidifier that is set at 45%. I can keep my gameroom between 45% and 50% fairly easy. I have noticed that when i tried to keep the room around 35% it would start causing decals and mylar issues. Mylar would start bubbling up. Around 45% seems to work well for me

Whole house dehumidifier. One of the best purchases I have ever made.

https://www.aprilaire.com/whole-house-products/dehumidifier/model-1870

In my experience any target decals or anyrhing stick on the 35% humidity will dry the glue out and cause problems. Im not sure if this happens every where but this is what ive had happen.
From my understand planking is caused from vast swings in temp. I keep my game room around 76 degrees unless guest are over with no problems. There should be some others that can way in on what causes planking.

I have a small unit which has been going every summer for years. It runs continuously, and maintains around 55% humidity with minimal temperature rise. It removes around five gallons of moisture from the basement air every three days.
Running a dehumidifier lowers the humidity, but also raises the temperature in the area you're running it in. A higher temperature will help to lower the relative humidity if the area is fairly well sealed from outside air. I try to keep it below 80° downstairs, but it can be difficult in the summer.
If we have a cool, dry day (not very often), I'll open the windows and screen door to drop the temperature.

Keep mine set to 50%, keeps the basement around 55-60 which seems dry enough to prevent mildew or other problems. I have a basic unit with a hose attached that goes into a 5 gal bucket so I don’t have to empty it too often. A couple times a week.

I have a high water table (I own a swamp, love paying taxes on that...), anyway... Set at 50%, separate meter (you need one of those, don't trust your dehumidifier) reads 47%. Runs often during spring/summer, not during winter. (Northeast) Drains into sump.. Mine last years, few recalled....easy disposal, place on curb... disappear

Unless your foundation leaks, the humidity in your basement shouldn't have anything to do with the water table. Mine is very high here as well, but the reason your basement gets damp is because the air in it is quite cool, and when warm, moist air (like now) interacts with it, moisture condenses on all the cool surfaces (including your pins). This moisture will eventually evaporate, but will raise the relative humidity in the room. As long as your basement stays cooler than the incoming air, this cycle will continue until the air is saturated with water vapor.
I used to get water dripping off my cold water pipes, but since I've been annually running the dehumidifier and keeping the room sealed from exterior air, it's remained cool and dry downstairs.

Have French drains, two sump pumps/battery backup....With heavy rains, the pressure under my basement floor is decent....I sealed everything years ago, but recently a few new cracks started, and water returned (only under extreme rain levels). Had four pumps running non-stop during 100yr floods in 2010, had water spraying out of stones in basement fireplace, and three inches everywhere else...if I lost power, would have been 6' of water..

It's an 80yr old foundation with a swamp less than 100' away, it's going to leak...(my pipes have never had condensate)

45-50 percent set

don’t run it in winter

They keep the Mona Lisa at 68 degrees Fahrenheit and 50% humidity. It's oil paint on poplar wood.

This is what I used also. Two zones for it - basement, and the other is when the HVAC is on it will work with the forced air system. I have a total of 11 zones in my house for heating and cooling when the HVAC is on (currently 3 zones in the basement, soon to be 4 once remodeling is completed).

Humidity generally hovers around 45-50% and is adjustable. Doesn't run a lot for the basement zone during the summer as it keeps up very well, and hardly ever turns on in the winter for the basement.
https://pinside.com/pinball/forum/topic/game-room-in-hell-a-multi-year-project#post-3588206

That's how mine is set up. Really works well.

I can't remember the %, but for electronics assembly it's better to have a bit higher humidity than lower, most big damaged fet spikes and such usually hit during cold days of winter with super low humidity.