sounds a bit like a desert cooler. I saw one in India, cools about
delta = 8C

Paul

News wrote:
"Puddin' Man" wrote in message
...

On Fri, 10 Jun 2005 10:15:00 -0700, M Q
wrote:



wrote:


Richard J Kinch wrote:



Puddin' Man writes:



What (aside from sanity, which I do not possess) would keep po' me

from somehow mounting a sprinkler or 2 on the roof, running them

with a garden hose, say, from 11 AM to 7 PM (to cool the house,
which retains heat like crazy)??

Physics.


That scheme is unlikely to be efficient, with lots of thermal

resistance

(insulation) between the living space and the roof, and it's the wrong
time of day to collect coolth, but Harry Thomason did something like

this

...

I believe that, rather than collecting coolth, he is trying to reduce
the infiltration of heat during the day.

You are correct, Kind Sir.


He is not trying to collect
the runoff water, which has been heated, not cooled. It doesn't cool the

house,

but just reduces the solar heating.

You are again correct, Kind Sir.


It would be more effective if
you have minimal ceiling insulation and minimal venting between the

insulation

and the roof (as is often the case in many "flat" roof houses).

Not the case. Standard-looking gable roof, R-30 insulation.
Little exhaust fan doesn't cool crawl-space much. Whole-house
fan is not used except late at nite and very early in the morn.

I'm still inclined to think that drastic reduction of solar
heat on roof surface would be very helpful.

Lots of folks water their lawns/gardens. I just wanna water
my po' scorchingly-hot roof. :-)

Anybody got ideas on how to mount, say, 2 sprinklers and
a hose on a gable roof without piercing any shingles?


In Spain & Portugal, stallholders use water running down the canvas stall
canopies, collect the water in a tank and pump it up again. It really does
cool it underneath. That is a fabric tent like roof. It must make a
difference on any roof though. How much, well I don't know.

Heavy insulation to keep the heat out must be a good thing.