Summer Heat: Cool it Down

Does SoCal have enough water available for that application?

I did find a nice side effect of a large rooftop solar system: the shade seems to keep the attic and ceiling cooler. Though determining the actual degree is confounded by multiple nearly simultaneous changes (e.g. reroofing with a more heat-shedding product, improved attic venting, and upgraded ceiling insulation, including discovering and remedying uninsulated portions that were beyond the view of building code inspectors).

The eave overhang of this house is also set right to prevent direct solar heat gain from all south facing windows during mid-summer, the sun doesn't start getting low enough to get through any windows until late August. (And that is still minor today). But that eave shade never covered the lower portion of the patio slider door, so two years ago I finally hung a roll shade from the eave in front of it, intercepting the great majority of that heat gain outside. It is much more effective than any reflective shade inside.

That dropped our AC use down to zero (not that we needed it much before, this is a mild climate zone). While hotter climates will still need AC, similar changes could reduce the load.

It is similar to this:

 

that works well when it's dry, not in our humidity unfortunately

many flat roof industrial buildings in arid climates use misting systems on the roof

 

The future is cold tubes.
‘Cold Tube’ Invented to Beat the Summer Heat More Efficiently Than Air Conditioning

 

Likely NOT......because to actually do anything useful, the surfaces need to be kept damp ALL DAY and an hour or so after sunset.
Moreover, if there are minerals in the water, you will NOT like the residue that is left.
And if the surface is metal, you won't like the rust that forms either.

Overall, a BAD idea.

 

Read the comments at the end of that article.
Just another form of "snake oil".

 

There are new building techniques which are more practical to deal with this if you were building a new dwelling

Here are just a couple of examples;

This is a solar board for building it has a silver reflective side to reflect radiant energy back instead of into the dwelling
Roof Sheathing: Silver Side Down - Fine Homebuilding

Passive home ventilation systems will remove heat from your attic and roof areas
Proper Attic Ventilation is Needed on Every Home | Solar Blaster

Heat reflecting shingles
Solar Reflective Shingles

in States like California there are products like metal roofing materials that reflect solar energy and are flameproof and resists ignition from embers to help make the entire home flame resistant.
A Metal Roof is a Fire Resistant Roof | Classic Metal Roofing Systems

All these may be a better alternative then using a precious natural resource like water in an area that has limited amounts of the resource.

For existing dwellings option are limited.

 

it is a mist system, very little water. it cools the air above the roof

you want to see water wasted in the desert? drive down the street at sun up and watch the rivers of sprinkler water

 

water is a funny thing. the quantity never changes, just the quality and location.

i suppose it's just a matter of weighing the energy necessary to get clean water to your door vs whatever other options there are.

 

Thermal management of human environment in a very broad perspective:

MIT’s Asegun Henry on “Grand Thermal Challenges” to Save Humanity From Extinction Due to Climate Change

Perhaps in some ways a bit overstated but that's in the eye of the beholder.

==
Specific colutions:

Global Cooling Prize

 

Growing up in Oklahoma, we had:

• swamp coolers
• four sack cloth wetted down

But that was before every creek and ditch went into a pond. The climate has become distinctly humid compared to what I grew up in.

Bob Wilson

 

6 homes in California that already have taken the new net 0 home mandate into real time

https://www.builderonline.com/design/projects/six-california-homes-that-are-ready-for-2020_o