"Paul Carver" <[EMAIL PROTECTED]> spaketh thusly:
>Here in Melbourne Australia, I know of only one grower who uses wet
>pads for cooling & humidifying. This system is a mystery to me, but
>I have to acknowledge that a much higher % humidity can be achieved
>than with my small swamp coolers with supplemental misters.
>Would somebody please explain the 'system' , and where I can
>resource the 'hardware'. Here we can have hot summer days to 40
>deg.C (100F), with humidity as low as 20%. It is a constant struggle
>in summer to ensure constant high humidity when temperatures go to
>100d. F . What are recycled PET pads?
PET (polyethylene terephthalate) is a wonderful little
polymer that is used in a lot of different applications, including
beverage bottles:
http://en.wikipedia.org/wiki/Polyethylene_terephthalate
Once done swilling the soda, they can either occupy a
landfill until such time that the earth's crust is subducted, or they
can be recycled. In the case of "swamper" pads, they probably last
for a similar period of time- or until they are gunked up with
carbonates and chlorides.
Don't know about any mystery systems and how they function
in .au, but I did manage to sit in on a talk from the wizards at the
Atlanta Botanic Garden (with their excellent Fuqua Conservatory) in
which they explained how they managed cold air in a place that's as
hot and humid as Atlanta. Recall that evaporative coolers function
best at low humidity, making Atlanta a poor choice for the use of
such chillers.
The architect or engineers or whatever that thought up the
Fuqua's conditioning system stole a clever little idea from cotton
twine manufacturing; in that industry, the material is processed so
fast that the product would catch fire from the friction. In order to
counter that, they used air humidified with pads that are wetted with
refrigerated water, rather than ambient temperature. So, if one can
drop the water temperature to, say, 4 C (down from 30 C outside), a
10-20 C temperature drop in product air could be achieved. This can
be boosted by spraying chilled water into the air (before or after
the pads- I forget) to absorb yet more heat.
Very clever solution. I'm glad I don't have to pay their
electric bill, though!
Cheers,
-AJHicks
Chandler, AZ
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