Jeff writes:
But the spec sheet says "Average current consumption for 12 VDC
systems over 24-hour period." This is the number of interest to most
boaters, and the proper measure is Amp-Hours.


Richard J Kinch wrote:
No it isn't.

Isn't what? Jeff is right, current consumption from a
battery bank is commonly (and correctly) measured in in
amp-hours, and this is the important spec to most boaters.


.... Current is measured in amps.

Correct.

.... Amp-hours are not a measure
of current.

Also correct, but then nobody (except you) is stating such.



You are in your typical error about the "simple cartridge" as a
comparative advantage. A cartridge for CO2 at 1000 psi is not "simple"
in comparison to ordinary refrigerants at 100 psi.

Really? Ever used a CO2 air gun?



"Vented freely" is a political, not a technical advantage.


It is a technical advantage if you are currently working on
the system.


CO2 is lousy refrigerant for all but a few unusual applications

That may be true, but the fact is that it works. The
technical properties of the refrigerant are not as important
as the intellgience of the person designing the system (and
the diligence of the person who builds/installs it).




You might as well claim that a steam engine is better than gasoline
internal combustion, because we can fuel it with grass clippings instead
of that expensive petroleum. Yes, it is possible to get steam power
from grass clippings, but it is impossible that it could work better
than a gasoline engine.

Depends very much on the relative mechanicl merits of the
two specific engines. I've worked on a lot of steam engines.
Some were great machines, others were a nightmare. Equally
wide variations in gasoline engines... of course, if you're
the type who can reel off encyclopedias of specifications
but in real life can't tell the difference between a
phillips head screwdriver and an atomizing fuel tip, then
you can smugly proclaim that one type of engine *must*
always be superior to some other type.

The basic answers for cruising refrigeration should be:
1- more insulation is always better
2- a clearly written manual is more desirable than superior
specs (true of most boat equipment IMHO)

Fresh Breezes- Doug King