This video, explains the design and principles behind a revolutionary desiccant based air conditioning. This extremely efficient, DIY air conditioner, is inexpensive to build and costs less than one half as much to run as a conventional, compressor based air conditioner.

Gravock

@ RebeccaKerr

The desiccating evaporative system demonstrated, handles pretty small BTUs.

A greater BTU system (enough to cool an entire home)
might be in terms of its physical dimensions, pretty large. 

When it comes to conventional evaporative coolers, there
are several concerns.

1. They don't work in high humidity environments (i.e. when it is raining).
2. They require a lot of maintenance, due to minerals accumulating on the
evaporation surfaces and minerals concentrating within the water reservoir.
3. They consume a lot of water.
4. One cannot re cool the air once it has been humidified by passing it through
the cooler again. Therefore they cannot function in an air recirculating modality.
Dry air must continually flow into the cooler and therefore also, other air must be
pushed out of the house.
5. They need to move a lot of air in order to be effective.
... ... ... ... ... ... ... ... ... ... ... ... ...
Of the  desiccating evaporative system several things come to mind.

Humid environments are some times very humid.  The desiccating components
might need to be of a considerable size in such circumstances.

Hot, dry environments tend to have a lot of dust in the air.  That dust will accumulate
in the desiccating evaporative system, reduce efficiency and at some point create the
need to clean the insides of the system. Replacement of the desiccating liquid and /or
the evaporative surfaces may be required.  Some considerations of environmental
impacts is merited in this regard.

This is a Little or no fresh air system.  Cool or not, and like refrigerated air, it will
tend to become "stale" after a while.
... ... ..
Questions I would explore.

Does it lose water over time ?
If so, what is the water consumption rate in this kind of system, not optimistically
but realistically ?
What is the range of air humidity (interior) it is likely to maintain.
What is the range of air humidity (exterior) it is likely to  best and / or properly
function within ?
How far does efficiency drop if the system is dirty ?
What is its ease of maintenance comparable to ?
How likely is it that pathogenic organism will propagate within the system
as compared to conventional evaporative cooler systems ?  Conventional
coolers have saturated / intensely  salty water.