Hello Friend ) said...

As for ductcleaning, 'if' you have allergies to dirt, spore, animal dander,
mold, dustmites, etc....ductcleaning is worthwhile -- especially if your
home is old.

You might be doing yourself a disservice.

In the 1990's, the CMHC in Canada and the EPA in the USA conducted
research and found there was little, if any improvement in air
quality resulting from duct cleaning. The basic reason is that ducts
are just passages for air -- there is no source of dust in ducts, while
there is in the rest of your house.

You can download a paper on this at
https://www.cmhc-schl.gc.ca:50104/b2...op=Z01EN&areaI
D=0000000016&productID=00000000160000000017

Another document is available at
http://www.cmhc.ca/publications/en/r...ech/95-205.pdf

In a quick glance at these documents, I couldn't find reference to this, but
I have heard that one study the CMHC did found that the cleaning process
can kick up a dust problem as build-up in ducts tends to remain in the ducts.
When it is disturbed, it becomes airborn again -- sort of like what can
happen with some asbestos situations: nothing harmful until it is disturbed.

--
Calvin Henry-Cotnam
"Never ascribe to malice what can equally be explained by incompetence."
- Napoleon
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