[quote=exsdgal]
Without knowing if the standing water under the house is a big pool or just small puddle(s) it is difficult to state the severity of the problem. Here are some general thoughts about the crawl space. Most crawl spaces have high humidity, generally from the lack of air circulation/ventilation[/quote]
There is a building code requirement for crawl-space vents to prevent humidity buildup. There should not be any standing water, which would cause black mold on the flooring joists.

I am seeing the approx amount is one 4×14 vent every 8 to 10 feet of crawlspace wall.

It is actually based upon area; approx 1 square foot ventilation per 150 square feet of crawl space.