From Name
Leo Moorman

-Diagnostics is the name of the game at such a moment, not trial
and error.
 
-Unfortunately good diagnostics can take time, and using the variety
available depending on the situation will indicate which type of system can be
excluded.
 
-Another advice is to work with one more experienced mitigator
that the home owner and mitigator believe can solve this problem.
That will give a more focussed result than via a group effort.
 
Comments/Questions on a few details:
ERV/HRV's are not supposed to be used if your original level is above
20 pCi/L, so unless you can get it below this value permanently by other means
you cannot expect it is going to work alone.
Was the outside radon concentration measured near intake vent at the same
time as the inside with the ERV/HRV running? What are they?
Are the outside vent openings properly placed, 10 ft apart?
Was the concrete tested on its radon emanation?
What did vacuum readings SSDC-test through slab show at which
distances?
What was pressure in pipe. What is under the 4" compact sand layer?
Is there an exterior or interior draintile pipe in soil?
Does the structure have a continuous footings or is it a
different foundation type?
and more .....
 
That is why I offered my help directly to the mitigator via Chrys outside
this forum, if he wants to work with me as I am also in Colorado, especially
since I am also working on a house with very similar parameters (80
pCi/L, down to 40 pCi/L) and have been looking at the possible solutions. I
feel mitigators need to be helped with such difficult problems by the larger
community because we do not want qualified certified mitigators to go under
due to a single house they cannot solve. However I am not sure that this is the
right medium, namely to solve the problem by communal input.
 
Finally, remember from the meeting: difficult houses are difficult for a
reason and you usually need details to isolate the problem and solve it
(and sometimes this "problem" does not have a single source). That is why I gave
a talk about such a house at the 2008 AARST, Las Vegas meeting that however was
caused by a different source, a manmade problem.
 
Leo Moorman
Fort Collins
Colorado
 
 
In a message dated 12/3/2008 8:44:52 PM Mountain Standard Time,
Radoncontrol@CS.COM writes:
Hi Chrys.Here is a copy of the response I left you on
RadonLeaders.org a week or so ago:My thoughts:1) Bringing in
large quantities of fresh air with the HP 220 is a bad idea; huge energy
penalty due to having to heat and cool air, probable moisture/ humidity
issues.2) 2300 sq ft pretty big area for any fan. That plus sand under
floor almost guarantees failure with one suction point. Last big basement with
sand that I mitigated took 4 suction points to reduce from about 20
pCi/L.3) Manufacturers tell me ERV/HRV at best gives approx: 70% radon
reduction.4) Two 100 gal. water tanks? Well water? What is radon
concentration in water?5)What was U-tube manometer reading on initial
installation? Was fan moving any air?6) What are pressure field
extension readings from initial installation? How far did pressure field
extend from suction point? (Shop vac diagnostics should always be done before
coring large hole in floor.)7) What type of HVAC system--gas or
electric? Where is furnace? Where does combustion air come from? Where does
return air to furnace come from? Is system "balanced" or does it depressurize
basement every time fan or heat come on?8) Positive pressurization is
a valid mitigation technique. Consult with HVAC expert.9)Were all
basement rooms and garage tested at the same time with all the systems off and
doors closed between rooms? This might show where problem
originates.10) What are basement exterior walls made of-- poured
concrete, hollow concrete block, filled concrete block? A little more
info might help us help you.
Henri BoyeaRadon Control ProductsPO Box
6263 Hendersonville, NC. 28793-6263ph/fax (828) 698-4960E-mail:
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