Author Options:

Terrace Cooling System - Ideas Answered

Hi, my name is Michael and I'm from Austria.

Nowadays we have about 38°C (100°F).
We have a Terrace which has a area of 33m² (355.21ft²).
This terrace has a roof, which consists of polycarbonate plates.

We have the problem that it is very hot on our terrace although we use awnings.

Now I've discovered some ideas how i could cool down our terrace.

The first one could be a water cycle, with a container and a pump.
Then the pump could pump up the water.
The water flows down the roof and flows back into the container.

I don't know if this is a efficient way to cool down our terrace?

The 2nd possibility I discovered is water mist.
I found this video to show the principle:

I don't know if it is possible to sit underneath the water mist without getting wet??

I just want some Ideas and oppinions.
Maybe some of you have realized their own cooling system?

I know how to program an Arduino and other microcontrollers and I am able to develop electronic circuits.
So I think i have the basic knowledge for building such a system, but I can't decide which principle i should use?

I am sorry for my bad english skills, but i hope that you can understand me. 

Thanks in advance



5 years ago

Madrid uses water mist to cool some shopping streets during the summer. A fine enough mist sprayed high will prevent actual drops from hitting you and make you wet. Even with little water this will probably have a strong effect on ambient heat.

The other system you mention is similar to how cooling towers work but if it streams over the roof i imagine it will mostly cool the roof itself and might do little to help with the terrace beneath it.


Reply 5 years ago

The cooling effect will depend strongly on the relative humidity - Spain is pretty dry in summer. I wonder how Austria is ?


Reply 5 years ago

Is the effect of the water mist cooling system really depending much on the humidity? Because in Austria the air humidity varies between 30% and 90% in the summer.

But in the planning phase I discovered a bigger problem.
I don't think that there is an pump with high pressure and low flow available.
First I looked at aquarium pumps, but I don't think that this pumps deliever enough pressure.
So I'm kind of desperate because I don't know where to look for this kinds of pumps? I found hydraulic pumps which could deliever such high pressures, but they cost at least 2000€.
But I look more for a Low-Cost Solution.
Or are there other cooling principles which are more realistic to build?


Reply 5 years ago

You don't need too high a pressure for misting. Take a look at the sprayers used for "aeroponics"

Yes, humidity is a critical parameter for the cooling effect. Look up "evaporative cooling" or "swamp coolers" for some more information.


Reply 5 years ago

I think that you are right...
cooling the roof didn't have the effect I wished for, i could only cool down 1°C!

Back to the water mist....
First of all I would need nozzles and a pump.
But I don't know where to look at for this things?
Is there any other application, where this water mist is used?


Reply 5 years ago

Water mist can also be used for certain plant watering systems. I imagine the pump you need would would produce a low flow but a relatively high pressure. The nozzle would need to spray wide but very thin droplets.

I don't know where you would be these components however.. You can try gardening stores or maybe an aquarium pump if it provides enough pressure. I suppose you could fabricate a nozzle if you cant find one. Experimenting with nozzle sizes and number till you get the proper mist.

Dont forget to take pictures of your progress and post an instructable!


5 years ago

Try painting the roof with aluminized roof paint. The silver color of the paint will
reflect the heat.

Also adding some kind of fiberglass insulation underneath the roof will provide
a heat shield .

I was once unloading an insulated box truck, parked in the sun
on a blistering hot day . The truck's refrigerator was off (never on),
but still it was cooler inside the truck than outside. So I know insulation
will help.