I'm wondering why radon vent pipes have to be at least the height of
the house to which they are attached. As long as the output of the
pipe is under pressure from the fan, I don't see why the vent pipe
cannot end just at the outside surface of the house, as long as it is
not an area where people congregate. Like behind a big evergreen
where the evergreen is close enough to the house that no one could
even get there. The height should not make it draw better, there are
no sparks to worry about, so what's the reason?
On Jun 23, 1:54 am, " firstname.lastname@example.org"
Yes, I agree that's the reason. If the discharge was located on a
side of the house where it's far away
from any window or door, then the problem of it coming
back into the house is essentially
eliminated. Although if there are soffit vents, some of
the air could still make it's way into the attic. Then you
still have the problem of people standing near it outside.
I don't know how you can say for sure where people
will or won't congregate. Just vent it where there is no chance of
any of it getting back in and be done with it.
On 6/22/12 11:15 PM, hr(bob) email@example.com wrote:
FWIW, mine was installed using aluminum rain gutter downspout pipe,
instead of PVC, from the fan to roof line. Not quite so obvious, and
easily painted same color as siding.
One thing I've wondered about. Why no rain cap, does the fan have a
rain diverter built-in ??
On Sat, 23 Jun 2012 14:52:55 -0700 (PDT), "hr(bob) firstname.lastname@example.org"
Having a cap does not guarantee no water or debris. Water can easily
condense as the temperature changes. So, the fan needs to handle
water regardless and to return to the original question, maybe the
pipe should be higher to avoid debris from trees.
On Sun, 24 Jun 2012 09:16:58 -0700 (PDT), " email@example.com"
One doesn't need to avoid "most" trees. One only needs to avoid the
trees in your particular installation. My vent is above the roof line
per code and that happens to be above the nearby small trees. If it
was at the roof line, it would not be. The OP asked why the vent
needed to be higher. I gave one *possible* reason. My main point was
why it is not necessary to keep rain water out.
You mistakenly assume anyone cares about what's really going on. Histeria,
and all (sorta like AGW). I had to put a system in my NY house, >20 years
ago, to sell it. There was no way I'd put it in for myself.
Well, I'm going to leave mine terminated on the outside wall about 20
inches above ground level with a dryer vent cap to keep critters out
until I am ready to sell the house, then I'll see if I even really
need it as my levels were about 3.5 in the middle of winter many years
ago, and the ground water levels have changed quite a bit with the
addition of storm water drains in a nearby subdivision that have
lowered the water table so much that my sujmp pump rarely even runs
From a practical standpoint, my guess would be that
it's OK. While there is the theoretical possibility of
the air making it's way back into the house via an open
window, door, etc, if the pipe terminates a reasonable
distance away, I would think it's unlikely. Also, the
radon exposure thing is cumulative over years and
years. Even if a bit of radon made it's way back in
once in a while through an open window, if you
average it out, I doubt it amounts to squat.
It would be interesting to see some actual experimental data that
shows how quickly a concentration of any gas dissipates after coming
out of a pipe like that into open
air when discharged. Going above the roofline is
definitely the safest, to code, not going to raise any
issues with inspections, etc.
Of course that all depends on the severity and where the radon is measured. In
my case it was varying between 4 and 12 pCi/l in the basement. I would never
have spent $1200 (in '93 money) on it for us. OTOH, my brother's house was
almost glowing (120 pCi/l, IIRC).
I did not see much difference between basement and upper floor. I sent
fliers out to others on street. Pretty much didn't care. I measured
neighbors newly built house, and it was elevated, but not like my 60 year
house. I got into measuring it and trying to remedy situation when I sold a
house. It measured just over at the time. They wanted it fixed. I did some
sealing, and hired another measurement, and it passed. They still wanted
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