Just wondering what climate you are in and if the floor in the crawlspace has a layer of plastic under a thin layer of cement?

My crawlspace is all concrete and i live in Delaware l

It's hard to dry out a crawlspace with humid air which is why many feel new, vented crawlspaces should be illegal in humid climates, generally east of Mississippi river.

It might appear things are improving with the fan, but you could be making long term situation worse as the building materials soak up even more moisture from the air. Drop the idea of crawlspace ventilation, seal things up as tight as possible and condition the crawlspace air.

Sounds like your crawl is better off than most with the concrete surfaces. Building an unvented crawlspace is a better solution than more venting. Do the work yourself to save costs.

What do you mean by crawlspace kind of? Cover any exposed ground or seal any existing plastic to walls and piers. A stand alone dehumidifier or replacing water heaters located down there with a heat pump water heater (if there is enough headroom) is more practical than pumping humid air into your home.

What is your attic situation? I'm betting it has a poorly sealed house-to-attic interface. By air-sealing at the highest ceiling plane (vented attic floor), you block the migration of humid, crawlspace air into your home from below. Air-sealing your attic will probably have better results than more crawlspace ventilation.

Our house had a fan to vent the very low-ceilinged attic when we moved in 34 years ago. It had a thermostat that came on when it reached a certain temp (have no idea what temp as DH was far to big for this crawl-in attic). It ran constantly.

Then the thermostat died. We found an electrician who was small enough to crawl in there to replace it. Then the fan motor died - no possible way to get the thing out to replace unless the outside peak vent was removed (which would have damaged the siding) and scaffolding put up so they could remove it and put in another (sloping lot).

So, I did a lot of reading about venting attics and discovered that all that fan was really doing was running up my electric bill. When I re-roofed my house a year later, I had ridge vents installed. There are no soffit vents connected to the inside of the attic - just soffits on the outside to hold the gutters away from the house - they are vented.

There is now far less moisture in the attic and that was what I wanted. No musty smell on the 2nd floor.

Moving air helps with an attic; not sure about a crawl space.

It depends on what kind of attic ventilation. Passive ventilation from eave to ridge is generally considered helpful, as long as it's not windwashing the insulation. Building researchers point out there is little need for hot, humid climates to feature this type of vented attic for thermal or moisture purposes. It's most useful where ice dams are prevalent.

Powered attic ventilators are almost never a good idea. Energy use of the fan is minor compared to other problems they introduce. They depressurize the attic, making poorly sealed house-to-attic situation worse. This increases moisture problems, stresses HVAC system and can backdraft combustion appliances.

Air-sealing the uppermost ceiling and providing code minimum insulation or better is the best way to deal with a hot attic.