Insulation, Radiant and Vapor Barriers - crawlspace condensation problem

Hi guys,
I am looking for help with a condensation problem in the crawlspace under my house.

It is approx. 25' x 30' in size and it slopes from about 1' to 4' high. The dirt floor is covered with plastic. There are 2 vents on the front of the house -below grade going into the crawlspace, they have been dug out around them. They are 6" x 10" screened and louvered so they can be opened and closed. The 2 vents on the backside of the house are same but above grade - I'm on a slope. There is also a cement block support wall that divides the crawlspace in half. It has an access opening at one end to get through to the other side 24" x 30" and has 2 cement blocks left off the top at the other end for cross-ventilation.

In the humid summer, the fiberglass insulation between the floor joists drips large amounts of condensation down onto the plastic covering the dirt floor. I am worried about mould forming on the joists or dry-rot.

Last summer, I took one above-grade vent out and installed an exhaust duct through it with one of those inline furnace duct booster fans (160cfm). With the duct sucking from ground level, it didn't help.

This year, I added another fan (200cfm) to the other above grade vent. It didn't help either.

There is a 24"x30" outside entrance door on the above grade side of the crawlspace. Would it help if I installed a screen on this door or should I try something else?

Any help would be greatly appreciated. Thanks.

Same problem different home. You can't dry a crawl out bringing in humid air! Close vents and insulate walls with 2 inch poly styrene. Add a 100 pint dehumidifier to remove moisture!

Thanks, for your quick reply. In checking my post, I realize I wasn't clear. The fans are blowing air out of the crawlspace through the back vents.

Thanks.

Thanks, for your quick reply. In checking my post, I realize I wasn't clear. The fans are blowing air out of the crawlspace through the back vents.

Thanks.

And that is pulling in hot humid air through the other vents to replace the hot humid air you are pulling out.

You're right, I never thought of that. I've been told its a good idea to create a sealed crawlspace. How should I go about insulating the walls and joists (spray foam)?

Thanks.

You lay plastic on the ground and up the walls about 6" sealing all the seams. then glue the styrofoam to the walls all the way up and fill in any voids.

Remove the insulation from the floor joists. If possible add a supply and return from your homes ventilation system and the craw space will be dry as a bone.

Check your local code 1st since in some areas it's code to have the vents like you have.

Thanks for your help. My ISP has been down, so I have been unable to reply to your post until now. I can't put a duct into the crawlspace because I have baseboard electric heat and Ductless Air Conditioning. Should I insulate the floor joists - or why not?
Thanks,
Jen