((Note: this is post of mine from a different site that is about a year old, but thought I would share it here too in case it helps anyone))
Old technology is once again getting attention, and this time it’s air-conditioners made out of terracotta clay.
“She was inspired by the Palestinian Jara, a traditional clay water container that is hung from the ceiling to cool water and cool the air. Specifically, the water contained in the hollow internal structure moves outward through the porous clay walls. With the heat of the air, it evaporates and is transformed into water vapor. This reaction absorbs heat from the surrounding air, cooling the water, the material itself and consequently the air in the room.” Forbes India In regards to Yael Issacharov.
There are two unrelated people currently being mentioned for promoting their designs using this technology; Monish Siripurapu(from India), and Yael Issacharov(from Israel).
Monish Siripurapu’s design is based off a beehive and uses a small pump to create a beautiful water fountain that both cools the air and can be used for gardening.
Yael Issacharov’s design uses no electricity, and instead relies on the naturally porous nature of the clay.
For dry and hot climates, this old technology could provide cooler air at an affordable price. The clay is readily available almost entirely world-wide, making it accessible and inexpensive.
"The humid clay traps some heat the air and the surrounding air gets cooled down to around 6-10⁰ C due to the process of evaporative cooling.“ EcoIdeaz in regards to Monish Siripurapu
Videos with more info:
Based on this information, I am wondering if a terracotta pot and a fan would have the same effect for a small room. Here’s a drawing of mine to help explain what I mean:
So apparently a swamp cooler for a single house uses as much water per day as it takes to water 250-1100 m^2 worth of lawn, or 125-550L per day. Not great for regions with water shortages, which have a pretty big overlap with regions that are arid enough for swamp coolers to be effective. Given the salt buildup, sea water is not an option, so you really need to spend a lot of fresh water to get this to work.
Honestly, I think solar powered electric air conditioning is more environmentally friendly in most use cases, at least until you cut massively on agricultural water usage.
Though of course the best air conditioning is shaping housing and lifestyles to need it less. Build into (artificial) hills or mountains, use shade, use air currents, live densely so less AC is necessary and other people can benefit from it. Work in the morning and the evening but take a >4 hour lunch/siesta break when the day is hottest.
As someone currently using a swamp cooler in a desert climate with daily temps around 40C, that statement is absolutely misleading!
A more accurate statement could be that they cycle 125-550L of water a day, but aside from what’s evaporated, it’s basically a closed-loop system, with very little water waste or loss.
evaporative coolers are very common in desert climates in the US. they work really great up to about 60% humidity and cost less than 10% to operate compared to ‘regular’ AC. they use little power (can easily be solar powered), and do not pollute.
i have both an evaporative cooler and an AC unit and have rarely felt the need to use the AC - the evap works exceedingly well for keeping the temps tolerable.
the only real downside is that it’s not just push a button and all your problems are solved. you need airflow. usually these things are mounted where the output vents into a central hallway or room, and you direct the flow of cool air by opening windows or doors - the path between the cooler vent and the open “exhaust” to the outside is what stays the coolest. Opening the whole house requires turning the evap cooler’s fan to a higher speed, but that’s so wasteful and we’re not ever using the whole house at once. i also turn it off when there’s a thunderstorm (because obviously the humidity spike makes this useless). It also doesn’t get used in the winter - it gets a canvas cover and some padding to seal off the air gaps so the house doesn’t get too cold and drafty.
it’s clear there’s a lot of people here who haven’t ever used or even seen this type of cooler, but i assure you this is common, and probably the most cost-effective summer cooling.
The water is recycled and run back through. You lose some to evaporation, but not as much as you said.
I used to work at a huge federal building and the entire place was evaporative cooled. They didn’t run through insane amounts of fresh water.
As somebody who’s used swamp coolers a lot, there’s no way those usage numbers are accurate
A minutes worth of a fire alarm sprinkler system for a whole house (about 567 litters per minute) is an insane amount of water to be putting out. It takes days for a house to dry out after on of those go off.
I say this to say that the high end number doesn’t make sense to me in a realistic usage case.