Watering roof to cool down apartment

Daily Life, Swiss News and General Topics
21
Water shortages are here.

Our municipality (near Lugano) has just informed us of a hose-pipe ban.

No watering gardens, no washing cars, no watering down of terraces and paths, etc. and no filling or topping up of swimming pools.

It is my understanding that this has already been in effect for a while further south towards Mendrisio.

22
Not really - and the living space will remain just as warm.. But great if you're installing air conditioning and can use the solar power during the day.

You could also add an inverter and 2 x 12v solid state batteries to power it during the night. What you don't use you can sell to the electric company!

23
Watering the roof could help get rid of a couple of degrees during the night if you do it after sunset. Doing this for 2 weeks per year is not much of a problem, if you compare it with people still having baths it's actually a better use of water. What could be done is collecting the water coming out of the drainpipes (in general), but water problems in Switzerland are an infrastructure problem mostly so...

24
It all depends on the build and the steps taken to mediate temperature.

We are on a roof top and have large windows facing all 4 directions (some of which are not sealed).

So far this summer it hasn't gone above 24 degrees during the day (and using a 750 W gaming PC and older Projector)

We do have a portable AC unit, if needed. But haven't used it at least for 4 years.

Again, depends on the build and actions taken to keep the place cool.

25
No benefits at all from the shadow? Assuming they are suspended a few cm from the actual roof, and not integrated in it...

This, yes, because you cool down the roof when there is no further exposure to warm it up.

It's also the best moment to water the plants, if you do it while there's sunlight it will be less effective and possibly damaging.