From Name
Leo Moorman

Timothy and Michael, a comment to both of you.
 
Timothy,
 
There seems to be a misunderstanding that non-idealities of the practical
world are not taken into account yet. Several of us have asked the
same question some years ago and answered it in various degrees.
For instance the imperfect world is already taken into acount when I
calculate and test on the performance charts that I calculate for each
individual situation in a way I will show below.
 
Michael,
There is no 'standard performance chart' you are hinting at, since there is
no 'standard radon system'.
(unless you choose one that is standard for you in your business, or
relevant to certain houses in your area)
 
The reason is as follows.
It all starts with the resistance of the cavity due to subslab and slab
condition you encounter which can be different every time you mitigate a house.
There (under the slab) is where the performance "real world imperfections"
start.
 
That is why I wrote a paper several years ago that has all three relevant
parts included:
 
(1) Cavity resistance,
(2) Pipe geometry (not an "ideal" situation at all, but is based
on any situation you can build and it involves details) (Bill
Brodhead's real world measurements on pipe friction behavior are included in
this part)
(3) Fan performance characteristics
(yes, altitude effects are adjusted in all three, as needed for the
location where the system is).  
 
When you understand the interplay of these three components you really
understand how the "real world" modifies how the fan choses its
operation point on the (ideal) fan performance curve.
 
This is in principle described on the AARST website (2008 publication) in
the link below.
Another publication has been approved that gives many more examples, of an
extreme and "standard" type. it is based on my talk in 2010, and will be
available soon on the same website.
 
Real world calculations are always checked against real world data of the
real systems that I and others have built, and they agree satisfactorily.
 
Leo Moorman
Radon Home Measurement and Mitigation
Fort Collins, CO
 
The link to the paper with the explanation of the above method can be found
here:
http://www.aarst.org/proceedings/2008/22-SOLVING_TURBULENT_FLOW_DYNAMICS_OF_COMPLEX_MULTIPLE_BRANCH…
 
 
In a message dated 4/21/2011 6:57:16 PM Mountain Daylight Time,
timpit@CHARTER.NET writes:
Boy, are you looking to start a fight or what ??  Radon guys
are very defensive about their fans. The various brands are not necessarily
all the same.  I suggest getting the specs and fan performance data
graphs and charts provided by the manufacturers, get you a big desk or an big
open floor, study them, and lay them all out.  You may well find that
some manufacturer's line of fans may have some "gaps" or "holes" in the
performance range that another manufacturer may have a fan that fills or fits
in the gap.
You may want to talk to some of the various folks at the other
companies, if you have been buying from AMG/Fiesta I am sure you have talked
to  *******(who is a great guy, with a wealth of knowledge), talk to the
other folks too (sorry *******, no offense).  Sometimes it may not
necessarily be that one manufacturer is head and shoulders above the rest, it
may be that your personality clashes with who you are having to deal with on a
daily basis, or that they are just a pain.....or maybe it's you that is the
pain....it really doesn't matter....you just need to find a happy
relationship.  I would say don't worry so much about 10 or 15 bucks price
difference....be comfortable or be happy.
 
I have not explored everything that is out there, and I am sure
that AARST or somebody has some studies of fan performance available somewhere
on some website, as I am sure that you and I are not the first folks that have
wondered the same things.
I would like to see a "Standardized Radon Fan Performance Test"
 where they hook the fans to a "Real World Application" such
as 20 feet of intake pipe with an elbow, and then 15 feet of discharge pipe
with 2- 45's. and and a 90 degree elbow.........or something.......don't give
me data that says this fan, when sitting on a test bench in some lab @ 3000
Feet of elevation, under perfect conditions, with nothing attached or no load,
pulls 125 CFM @ 1.25 inches of vacuum....that does not tell me much......tell
me what it pulls in the real world under imperfect, working
conditions......and for grins, say that while doing so it creates "X" sones or
decibels of noise.......but compare apples to apples.......all the
manufacturers have to play by the same rules and test under the same loads and
configurations. Also give me a chart that says if you use this 4" diameter fan
(125 CFM @ 1.25) and you choke it down with 3 X 4 ferncos to 3" pipe, then you
are only going to get "X" CFM @ 1.25.
Anyway that being said, I will e-mail you individually about my
opinions of the various brands of fans out there, as it is hard enough to make
a living around here, without having to deal with liable/slander
lawsuits.........I will tell you, at the risk of the Chinese mafia showing up
on my doorstep tomorrow, that if somebody tries to sell you a Chinese fan, or
any fan with oriental looking writing on it, turn around and run like your
hair is on fire.
On Thu, Apr 21, 2011 at 6:29 PM, Michael Talotta wrote:
  Hello all,
I've currently been using Festa fans but have always been curious
about Fantech and Radonaway.  Is there any one fan that out performs the
others?  I look forward to your feedback.
Thanks, In advance,
--
Michael Talotta Northern Vista  
Radon Measurement & Mitigation Provider
77 Webster Street
St Johnsbury, VT  05819
********** RN PROF  (Subscription changes - archives) -
********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1
***********
 
********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ***********