Dear Arnold,
Although there was no, definitive, data accumulated positively
establishing efficacy of ionic vs particulate agents......the anecdotal
evidence did seem to favor, somewhat, particulate agencies. We utilized
solutions of varying ratios, from 90% ionic X 10% particulate, to 70% ionic X
30% particulate. The anecdotal results did, in fact, accrue in favor of the
higher particulate liquids. However, since the control rates of all solutions
were so high (never lower than 80%), it is rather academic----and
speculative---to attempt to use this (uncontrolled) study as a basis for
establishing an effectiveness superiority.....for one or the other.
Our staff seems to be divided over this issue; and, probably,
rightly so. The reason being that the exact range of efficacy of pure ionic vs
pure particulate solutions has---to our knowledge---never been scientifically
concluded (especially considering the difficulty of generating CS of 100%
solely ionic, or solely particulate nature). To wit: by establishing a
suitable range of tests over a variety of repeatable conditions-----especially
in vivo----which would allow objective results to be unfailingly quantified.
It is my PERSONAL opinion that high particulate
concentratilons do, indeed, exhibit superior control effects for topical
applications----most especially in cases where residual mass/volume of the
control agent are of increased consideration. I am not so confident about in
vivo circumstances.
In closure I would suggest that the course of prudence would
suggest a CS containing at least 10% particulate silver derivatives. I do
suspect that each demonstrates advantages under different specific
circumstances; if correct, recommending a policy for using CS solutions
containing appreciable percentages of both representatives, appears most
sensible.
Hoping I have not opened the door for excessive conjecture......
Sincerely, Brooks Bradley
----- Original Message -----
From: Arnold Beland
To: [email protected]
Sent: Monday, August 27, 2001 8:06 PM
Subject: Re: CS Tip of Possible Interest
Thank You Brooks, for some useful information. At the risk of starting a
skirmish, should we use Frank or Ivan's CS for this?
Best Regards,
Arnold
----- Original Message -----
From: brooks bradley
To: [email protected]
Sent: Monday, August 27, 2001 5:16 PM
Subject: CS Tip of Possible Interest
Recently, we completed an investigation which yielded
information I believe to be of possible value to the list membership.
While it is well known that CS solutions as weak as 5 ppm are
of value when impinged upon the surfaces of conventional air conditioning
filters, there was small data available as to how effective. We found that
approximately 3 ounces of 10 ppm CS sprayed over (both sides) of a 20" X 20"
X 1" AC intake filter.....once every 10 days, reduced the general viable
bacteria/virus populations (expressing on the filter surfaces) to 5%--or
less--of those found on the control filters. In some cases, where 20 ppm was
used, and the interval for filter cleaning shortened to 7 days----the efficacy
improved to better than 98%. It is of interest to note that some filters were
mechanically/pneumatically cleaned by simply knocking them against a screened
surface and exposing to 60+ psi cleaning via air hose nozzles 4
times....before being replaced with new ones-----without substantial
degradation in overall system performance.
Of note was, free-air samples from areas serviced by a
$1000.00 air-scrubber, contained MORE live pathogens.....than did the CS test
areas utilizing the foregoing arrangement of CS impregnated intake filters.
One word of caution.....because of the large, initial, wetted
surface of the intake filter it would be prudent to check the filter for
heavier-than-usual accumulations of dirt/dust particulates at about 5 days.
after the initial installation.. This is of special importance in areas
exhibiting high dust concentrations. It may be of import for members to know
that approximately 80% of all A/C system failures have their primary cause as
"restricted air flow"......mainly from occluded intake filters (this includes,
but is not limited to: frozen evaporator surfaces, compressor failure due to
excessive work-load, continuously high discharge pressures,etc.)
I hope this information is of value to
some.
Sincerely, Brooks Bradley.
