Re: Cooling attic (and home) by spraying water on roof (shingles)- good/bad?

[Some Guy <Some@xxxxxxx>]

Phil Scott wrote:

> > Doesn't a mister waste water by atomizing it and then the
> > wind will blow it away?
>
>      The latent heat of evaporation for water ...

I still don't see an effective way to arrange a residential cooling
system based on the evaporation of water.

I don't think you can concentrate and deliver a substantial amount of
heat to a surface you can cool via evaporation.  Evaporative cooling
would be effective if the heat inside a house could be brought to an
out-door device who's surface temperature is well above boiling and
the application of water would result in evaporative cooling.

> Evaporative cooling would be limitlessly popular if it
> did not add an equal amount of humidity in the form of
> 'steam' to the air it was cooling to *sensibly lower
> termperatures.

So what you're saying is to mistify the air circulating in a house in
order to cool it.  I don't think that would work once you've saturated
the air (ie humidity > 75%) not to mention the effects of saturated
air on items in the house, the wood, the machinery, etc.

I think only the roof makes a workable item to cool with a water
cooling.  It's designed to get wet, to collect runoff, and gets very
hot in the summer, and cooling it can lead to reduction in cooling
requirements of the house.

The only thing that makes more sense is a temporary tarp or canopy to
cover the roof during the summer (to be taken down during nasty
weather, storms, etc).