Is it possible to make an affordable absorption refrigeration unit for home use?

Your question is a good one if a bit vague and relative. Of course it is affordable (depending on your definition of affordable). Define home use: cooling a beer, a refrigerator, a room or a full house? Realizing that the relationship between affordable and home use is now inversely proportional... here's some background:

Patent Coverage

The first Icyball Patent was filed on June 27, 1927 by David Forbes Keith, of Toronto, Ontario, Canada and issued on Dec. 24th 1929. The patent has 7 figures included. Fig 1 is an overall cross sectional diagram. Fig 2-4 are external features and construction. Fig 5-7 are charging and operational diagrams. These figures are included in the Patent link but are included here for those that do not want to wade through the patent.

A second improvement Patent was filed on Feb 20th 1930 by Russell T. Smith assigned to Crosley Radio Corporation and issued on June 23rd 1931. The second patent has 1 Figure showing a cross sectional view of the Icyball showing changes and general operation.

Obviously, there is the challenge of scale, material strength, pressure etc... depending on the size of the cooled space. The most interesting thing about this invention is the fact that a 90 minute heat cycle, yeilds a 24 hour cooling cycle...

Hope that helps :)

When I grew up we had a gas fired refrigerater that used an ammonia absorption refrigeration cycle. I think they finally went out of favor when materials of construction allowed for cheaper more efficient freon systems.

Bottom line, is you can make one, but why would you want to?

pretty expensive for small system, needs steam or other energy source of the type. needs large tanks for proper heat exchange.