Kenneth Elwell wrote:
It is basically a powered version of an ice house, working on a small scale and daily schedule.
The A/C unit works in reverse to create a block of ice, so that when the A/C runs forwards (cooling the house) the ice is melted by the waste heat, reducing/eliminating the need for the compressor to run (the costly part of the A/C to operate).
The main benefit in a market like California, (where the company was) with high energy rates and peak pricing, is to be able to shift the load to "off-peak" times, using less expensive electricity.
There are commercial HVAC systems (e.g. Trane) that create a coolant slush during the off peak hours to be used for air conditioning during the peak hours. The same idea could be done with solar during the daytime to store additional cooling for night. I have heard of something similar for truck air conditioning, so they don't need to run the vehicles on idle while sleeping.
I have an RV with a 3-way fridge. The propane and cooling system are accessed outside the vehicle for safety, a factor you should consider if creating your own system. They frequently have problems because they need to be level to operate. Mine is 15 years old. I needed to clean the propane nozzle to get it working. A replacement is over $1K, so expensive, finicky and potentially dangerous. All RVs with propane include a propane alarm.
I like the Wofati cooling idea or any with thermal inertia. I have heard of someone using the underground tube as a house cooling idea but having it first come through to a cooling cabinet in the kitchen. This is good for fruits and veggies, cheeses, yogurt, but probably not meat.