Sprinkler on the roof: WATER AS AN ECOLOGICALLY SOUND HOME COOLING AGENT

[Elwar]

I wonder if running a soaker hose along the top of the roof would do it.

 

[Bruno]

I wonder if running a soaker hose along the top of the roof would do it.

It sure might. And you could hook up a timer to it.

 

[Jordan]

I wonder if running a soaker hose along the top of the roof would do it.

I buried a hose underground in my garden with the open end capped off.

Every 2 feet, where I plant my veggies, I have several large holes in the hose.

To water, I just connect it to the valve, turn it on, wait a while, then turn it off. Easy as hell, and the pressure builds equally throughout the hose after a few seconds so all the plants get exactly the same amount of water.

I would imagine it would work similarly on top of a roof...and after reading this I'm thinking about trying it.

 

[Jordan]

Water flowing turbulently in thin film produces extremely efficient heat transfer, especially if there is a phase change (vaporization). On the other hand the lowering of attic temperature will only have a modest effect on internal temperatures depending on the structure. Plus there would be a big spike in water use if lots of ppl did this.

That was my concern as well, I'm not too certain that the heat in an attic transfers that well through the home itself.

Since my home is brick, I have a feeling that I could realize greater savings by cooling the brick since it makes up a greater surface area and is actually in contact with the walls of my home. The roof, on the other hand, is separated by both an attic and insulation, and it is on top (heat rises) of the house compared to on the side of the house.

 

[Elwar]

I buried a hose underground in my garden with the open end capped off.

Every 2 feet, where I plant my veggies, I have several large holes in the hose.

To water, I just connect it to the valve, turn it on, wait a while, then turn it off. Easy as hell, and the pressure builds equally throughout the hose after a few seconds so all the plants get exactly the same amount of water.

I would imagine it would work similarly on top of a roof...and after reading this I'm thinking about trying it.

I love those soaker hoses. I have one on a timer buried and looped around my fruit trees. When they kick the water restrictions back on, my trees will be just fine.

 

[sratiug]

I wonder if running a soaker hose along the top of the roof would do it.

I'd get a white one, or a silver plated one.

 

[MelissaWV]

Sprinkler on the roof: Way more efficient a cooling agent than Fiddler on the roof.

 

[sratiug]

Thought some of you might be interested in this idea - especially we Texans.

http://www.doctajstutoring.com/webdoc22.htm

It seems the RPF is behind the times. I found this a few years ago.
http://roofcooling.net/

SINCE 1981 THE LEADER IN ROOF MISTING TECHNOLOGY

 

[Elwar]

Sprinkler on the roof: Way more efficient a cooling agent than Fiddler on the roof.

Unfortunately you're a little too late with that valuable information...

 

[Bruno]

Sprinkler on the roof: Way more efficient a cooling agent than Fiddler on the roof.

Are you trying to seduce the forums with your avatars?

 

[TruckinMike]

Double roof. A roof on a roof with air channels in between. Its kind of like a giant tree shading your entire roof, but without the leaves, limbs or storm damage.

TMike

 

[Rael]

I'm skeptical as to how effective this would be. If you have decent attic insulation I don't think the difference would be that much. (And if you don't, I would suggest getting more insulation before buying sprinklers.)

Also, 88 gallons is alot of water.

Another option is to paint your roof white.

http://lifehacker.com/5326467/save-money-on-cooling-with-a-white-roof

 

[Rael]

bump

 

[buenijo]

Thought some of you might be interested in this idea - especially we Texans.

http://www.doctajstutoring.com/webdoc22.htm

This is a good post. In particular, note the experiment described in the link that used water to cool the a/c condenser. Not only is this configuration more practical, it should also be more effective (of course, one could water cool the roof as well). For retrofitting an existing unit, I expect a fine water mist to see best results while using a lot less water. Based on the results that I've seen in other configurations, I would not be surprised to see the electrical consumption from such a system be reduced by 50% in a dry climate.

 

[Romulus]

I expect this to work well in houses with vaulted ceilings too.

 

[noxagol]

You could also dig a tunnel under ground, 4 or more feet under ground, that leads to a box unit that surrounds your AC unit outside except on the top. This way, when the fan kicks on it will use the cool air from underground, pulling it through the tunnel with a hole on the other side to pull fresh air in, instead of the hot air outside. This would produce a much better cooling effect than regular and would be cheaper long run and easier to set up, then water misting cooling.

 

[Elwar]

You could also dig a tunnel under ground, 4 or more feet under ground, that leads to a box unit that surrounds your AC unit outside except on the top. This way, when the fan kicks on it will use the cool air from underground, pulling it through the tunnel with a hole on the other side to pull fresh air in, instead of the hot air outside. This would produce a much better cooling effect than regular and would be cheaper long run and easier to set up, then water misting cooling.

That is similar to this concept:
http://mb-soft.com/solar/saving.html

 

[dannno]

Where's Suzu?

 

[TruckinMike]

Double roof. A roof on a roof with air channels in between. Its kind of like a giant tree shading your entire roof, but without the leaves, limbs or storm damage.

TMike

TruckinMike is right on the money with that idea! LoL!

As an experiment --- When I re-built a small 12x20 portable building I decked the roof with painted 1/2" plywood (took temperatures), then one layer of 30# tarpaper, then I placed 2x4's every 16" (running with the roof rafters), like studs but on the side (creating a 1 1/2" gap), On top of that I screwed down 5V sheet metal roofing. At the peak I built a raised cover that allowed the air to flow unimpeded. The convection air flow travels from the lowest point of the roof up through the 1 1/2" gap and out the peak. The inside wood temperature difference between the painted plywood (bright white) and the air-gapped 5V sheetmetal was an amazing 25+ degrees. (hot summer day)

and just to check air flow volume I held a lit a cigarette lighter at the base of the roof -- I could hardly keep it lit -- the convection was working as predicted.

In summation, water is cool, but it presents a lot of problems - Shade is the best, if you don't have a tree, build a double roof.

If I every build another house, I will have a double roof with a convection air flow gap. Either that or build a huge cover over the entire house.

TMike

 

[TonySutton]

I have seen people build separate roofs over trailers down south. It was either 4x4s or 6x6s coming out of the ground with a roof attached. Here is a variation to that idea