'Invovative' Cooling system

My kind landlord, a friend to boot, has suggested that as additional cooling in summer we install a sprinkler system on the room of my roof top apartment.
The idea is to turn it on for 10 minutes or so and the resulting wetting of the roof will cool down the whole apartment for that crucial return-home -for lunch hour or so.
Landlord said it was the method of choice in the mountains where no electricity for aircon was available.
Any comments on this one. Much as I like the idea it sounds hairbrained to me.
Perhaps if we left the sprinkler system on for hours at a time which would then be a collosal waste of water.
And yes I do have aircon in the two bedrooms. Its the large living room area which is hot as hell.
Go on tell me its a briliant idea and will work.

You see this on a lot of factory roofs out in the boonies. Yes, it works… to a degree. Better method is to stop the roof from getting so damn hot in the first place. An old apartment I had (top floor) we put down 4’ x 8’ sheets of 2" thick polystyrene. Weigh the sheets down with bricks so they don’t fly away. Being white, the sheets reflect a lot of heat off the roof and the material helps reduce the heat that can pass into the concrete.

Water is too precious to waste on a job like this.

how about painting the roof white…

[quote=“braxtonhicks”]how about painting the roof white…[/quote]More expensive than the polystyrene sheets (at least when I priced it, ten years ago) and no insulation benefit.

Water is however very cheap here. Where does one get polystyrene slabs then?

[quote=“hexuan”]Water is however very cheap here. Where does one get polystyrene slabs then?[/quote]That is a problem… it encourages waste and robs the system of sorely needed investment capital.

I got my polystyrene sheets from a bulk supplier in town. They were selling the stuff for packaging, insulating refridgerated trucks etc. There are plenty out there. Yellow Pages ftw. :wink:

Another solution, build a roof over the roof :laughing:

Those polystyrene slabs sound like they could work on a flat roof. My rooftop is iron and pitched. Come the next typhoon a roof of weighted poly slabs would be circulating the neighbourhood with a brick or two along for the ride.
And a more thorough fixing of the slabs sounds like a mission, as does building another roof. I’m starting to think a couple of sprinklers on the roof might be worth a try. Sure its a waste of water, but if they’re used sparingly - 10 minutes or so daily - I could live with it. Imagine the cool crisp air that will be mine. Ha.

[quote=“Dial”]My rooftop is iron and pitched.[/quote]Sorry. Somehow I had the impression yours was flat and concrete like the other 90%. I guess that leaves the water spray thingy, but running that for 10 minutes does nothing. The only way this works is leaving it on all the hours the sun is high in the sky to cut down on the amount of heat that soaks into the building in the daytime. Once the heat is in the building itself a spray on the roof is not going to do much I’m afraid.

Yeh, you’re right its not going to work without wasting s…t loads of water. An even more low tech idea which works ok is to soak a big square of cotton - sheet size or thereabouts - in cold water and then turn the fan on it. The result is a definite cooling of the air.
Anyway what the heck, the worst part of summer in my experience is the early days when you’re body is still gettin used to it.

Thanks for the info.

IMHO nothing beats taking a cold shower and laying in front of a fan (nakid.)

During band camp in university (in 90-degree weather, 8 hours a day for six days doing a very vigorous marching style), I filled a 2.5 gallon jug with ice then added water and drank from that. The resulting severe brain freeze from drinking it helped to cool the rest of my body down.

I also used to get a paper cup, fill it with ice and blow on it to get the cool air from it.

A tub of cold water to put your feet in will also cool off the rest of your body as well as filling (but not to capacity) swimming muscles with water and then freezing them.

I’m assuming that you’re not planning to go out… :smiley:

When water evaporates, it requires energy, so it will suck the energy from the environment, cooling your roof. This is a good idea to water your roof for a few minutes each afternoon. The Japanese are watering city roads on hot days, and they’ve found that it significantly cools down not only the road, but the whole neighborhood by a few degrees.

A fan blowing directly onto you will provide several degrees of cooling. You can also staple foil onto the inside of the ceiling to reflect some of the energy from the sun back into the sky.

[quote=“twocs”]The Japanese are watering city roads on hot days, and they’ve found that it significantly cools down not only the road, but the whole neighborhood by a few degrees.[/quote]Talking about the Japanese, they are also doing the more environmentally-friendly thing of encouraging the planting of rooftop gardens, in cities at least. It keeps buildings cooler in the summer and warmer in the winter.

Sorry, this doesn’t help the OP, but I just thought I’d mention it as it seems like a great idea and I hope more city planners around the world start doing the same.