A comment made on the previous post sparked an idea in my mind that my friends in more humid climates than that found here, might find our way of keeping cool on hot and dry days quite a novelty.
Though sometimes called "air conditioning", it is nothing like the usual air conditioning most of us are used to.
You may have noticed, if you've been here, these boxes on the roofs of houses here, like this one:
The pump carries the water up to the top of the box, where it is then allowed to drip over the four sides.
These four sides have tiny louvres, which allow the water to evaporate, in the hot air drawn in by the fan and then the cooled air is ducted into the rooms of the house. Excess water falls back into the bowl and subsequently re-circulated.
Two words from my General Science days in secondary school summarise this process: latent heat.
Is it effective in cooling the house?
This recent shot shows the external and internal temperatures in our house recently (ignore the date and time, as I did not set them).
This method of "air-conditioning" ceases being effective when humidity starts to exceed 80%, in my experience.
However, for the whole hot season, we'd get maybe 3 - 5 such days, if that many. I much prefer the 40°+ dry days to humid weather.
For humid days, we use the bedroom "real" air-conditioning to sleep in (given to us by Son No 1, when he upgraded his). This season, we've used it once.
We've used this "air-conditioning" from the early 80s, and about 4 years ago had to replace the whole system, as the side panels had rotted, the insulation round the ducting had also disintegrated and it was generally no longer efficient.