Crawl space fan placement?

[Gary G™]

Not really. .........

[Gary G™]

Progress.
Just got out from under the house; the two ventilation holes I sealed have stopped allowing direct water penetration into the crawl space.
It’s been raining here daily so the soil is still wet.
I turned the fan on again—we’ll see what comes.

[srv52761]

Progress.
Just got out from under the house; the two ventilation holes I sealed have stopped allowing direct water penetration into the crawl space.
It’s been raining here daily so the soil is still wet.
I turned the fan on again—we’ll see what comes.

Gary, remediating high humidity to mitigate mold potential is what I do for our school district.  If you can wait a week, I can loan you a couple of temperature/humidity loggers for a while.  

If you can't get the rh under 60% on a consistent basis, you should consider a more aggressive approach.  It is a lot less hassle to prevent mold than to deal with the aftermath.

If you are interested, shoot me a message.

[Bob10]

I had a water heater supply line pop about a month back probably 7 inches of water bailed it out and set this machine to move the air across it
got the job done quick.  I was surprised at how much difference a day made.  While not completely dry the top of the dirt was solid no more slipping around and the noise wasn't bad

https://www.homedepot.com/p/RIDGID-1625-.../202942745

[blackhat]

Ventilating with outside air will never get the humidity below ambient outside. Period. You want drier in that space you need to seal it and mechanically remove moisture. No silver bullets. A ground barrier is pretty much a standard first step.

[srv52761]

Ventilating with outside air will never get the humidity below ambient outside. Period. You want drier in that space you need to seal it and mechanically remove moisture. No silver bullets. A ground barrier is pretty much a standard first step.

This is pretty much the case.  But many older codes still think that ventilation is a solution. 

 In fact, if  the space above is cooler continuously, then the insulation, which is designed to slow heat transfer but not stop it, will sometimes be cooler than the dew point.  All ventilation will do then is push more of that moist air next to that cooler surface. 

Ventilation will reduce relative humidity if you have a moisture problem from ground source.  But it will usually only go from a terrible situation to a bad situation.

[frule]

Ventilating with outside air will never get the humidity below ambient outside. Period. You want drier in that space you need to seal it and mechanically remove moisture. No silver bullets. A ground barrier is pretty much a standard first step.

This is absolutely the case!..........OP: Encapsulation plus a dehumidifier is the way to go. Almost all encapsulations require a dehumidifier.
It's a diy project if you are so-inclined. I placed a 6 mil vapor barrier on the floor and ran it up the wall a couple of feet. Permanently sealed ALL vents and penetrations on the side wall and floor. Placed 1" foam board on the side walls up to 3" of tghe sill plates and removed all of the old fiberglass insulation between the floor joists. All seams need to be taped or caulked. I added a Santa Fe dehumidifier (Aprilaire is good too). 

This keeps my 3,000 square foot crawl space at 50% (or below, if I wish) relative humidity easily. It's dry, warm & clean down there with no odors and no mold. The floors are as warm in the winter as when I has fiberglass between the joists.Plus you can see the floors with the insulation gone, which is a big plus. I still have occasional water intrusion, but it dries up quickly. I'm in mountainous, but very humid, East Tennessee.

The simple fact is that when fans push air out, they pull in warm, humid air.

[Mr_Mike]

Seems like you need to address exterior drainage issues as a first step. Regrade or add subsoil drainage to the east side. Without that, you are fighting a larger problem than necessary.

Does the house have a perimeter drain tile system at the exterior footing and does it work?