[S-F]

Originally Posted by Xringer

Somehow, that doesn't sound quite right. If it were true,
then I could use a little 1/4" line for the blower exhaust output..
Since there would be no flow, 15 seconds after the fan started up..

In radon literature, the term I've seen, is "Ground Air", and people think it
actually exist under your slab, and it can be pulled right out of the
ground, along with any radon gas.

I've seen pics of a guy testing a 4" holes in a slab, using vacuum gauge and shop-vac.

IMHO, I think the idea is to pull air out of the slab at one point, so that
all the other little leaks in your basement floor, will be sucking air, out of the basement.
So, air will be sucked into my other sump holes(& floor cracks) and flow underground,
over to where my Radon sump was being vacuumed..


It might be easier to understand, if you looked at it like a flooded basement, with 4 sump holes, but only one of them has a working sump pump.
That one pump is going to lower the water table under the house.
It's going to suck the water out of the other sumps.. The hard way..

?
You want to leave all but one sump hole open and suck air through the dirt beneath the slab?

OK