When I look at how houses/offices are cooled in my area I see that refrigerant cooler is far more popular than evaporative cooler. I did not find any company which serves evaporative cooler services/devices so there must be some downside of evaporative cooler which seems to be more sustainable.
Why refrigerant cooler is more popular than evaporative cooler?
You have to also consider the climate where each type of cooler will be used and how each type of cooler works.
Refrigeration coolers transfer heat from inside a building to the outside. However, the hotter the outside temperature the less effectively such coolers work. If the outside/atmospheric temperature is 50 C or higher, such coolers will struggle.
Evaporator coolers work by putting moisture into the air. This works well were the air is dry, such a deserts, However, in tropical locations or coastal locations, where the air is already humid, putting more moisture into the air doesn't help with cooling, it only makes the air more humid.
Given the right conditions, refrigeration coolers can cool the inside of buildings to 16 C or 18 C, but evaporative coolers generally can only cool down to 22 C or 24 C.
Also, refrigeration coolers allow buildings to be closed off to the outside - all the windows and doors being shut. Evaporative domestic coolers work on the basis of continually flowing air through the building & they require a opening to allow the "exhaust" air to vacate the building.
As the name says, for evaporative cooling you need a fluid to evaporate, and you would have to replenish this constantly.
Even if you use simple water, you would need to make a connection to your water supply, and you would have continuous (although small) costs.
Sustainability is not the primary reason to choose between the two, it's ease of use and price.
Obviously, in the minds of your population, the refrigerant method wins.
Heat pump coolers are used in humid climates. Evaporative coolers are used in desert climates. Heat pumps are more popular because more people live in humid climates than live in deserts.
Where the climate is dry enough, an evaporative cooler is much cheaper to run -- you're running a fan and a very low flow water pump. A heat pump based air conditioner still needs a fan to distribute the cool air, and often the same water pump to dispose of condensate. (Although it may be disposed of by gravity.)
