I agree. There are situations where air-cooled units are more practical. But
trying
to say the the current draw of a water pump is somehow a factor vs the
current
draw of the fan in an air-cooled unit doesn't really hold. As to whether a
thru-hull
and a few more feet of hose represents a negative aspect is up to the
individual.
Water cooling isn't restricted to holding plate systems. Even AB offers
water-cooling
options for their evaporator systems.

Doug
s/v Callista

"Jeff" wrote in message
...
Again, this may be true, but it might not be appropriate for all systems.
Adding a thru-hull and more components probably isn't worth a few
Amp-hours savings.

From Richard Kollman's site:

28. Question: Why would I want air cooling when water is more efficient?

Answer: Boat refrigeration systems smaller than ¼ HP are generally air
cooled for best performance and long term reliability. There are few
conditions where the seawater cooling can out perform air cooling on these
small units. To dispose of the heat in a boat from a small Danfoss
refrigeration system is about the same as disposing of the heat generated
from one person onboard, three hundred BTUs per hour. It is true that heat
from larger refrigeration systems must use seawater because the heat can
not be disposed adequately of onboard a boat.

http://www.kollmann-marine.com/answers.html#28


And, what kind of pump is only a half Amp? Most of the circulating pumps
for DC belt driven systems seem to take an Amp or more. The traditional
March 809, for example, is rated at 1.5 Amps. Of course, the pump for a
Danfoss system could be much smaller.

Doug Dotson wrote:
The water pump on my system draws less than 1/2 amp. Using a water-cooled
system saves enough energy to more than offset the overhead of the pump.

Doug

"Jeff" wrote in message
...

It may be true that water cooled is usually more efficient, but for a
minimal system based on a BD35, the added efficiency may not be worth the
power use of a water pump. This is a small issue with a large holding
plate system because it only runs one or two hours a day, but the small
evaporator based system may run 8 hours a day, and the water pump would
then add a lot of overhead. And, it adds a through-hull, strainer and
plumbing, and can get clogged with silt. This may be worthwhile
Downeast, where the water is 52 degrees, but might not be in the tropics.

Doug Dotson wrote:

A water-cooled unit is always more efficient than an air-cooled unit.
Unless
somehow the air temp gets cool for a long period while the water temp
stays
high. Not very common. This is why all the larger units are
water-cooled.

Doug
s/v Callista


"Jeff" wrote in message
...


A lot depends on the size of your fridge and how you use it. If you
can go into a bit of detail, such as the size of the box(es), freezer
requirements, and the nature of your cruising, you might get better
advice. For example, if you cruise in cold water, a water cooled system
would be more efficient. But if you power each day (or run a genset
for A/C) then the power issues might not be important to you.

I have larger Crosby (actually part of A/B) holding plate system for a
separate fridge and freezer system that I've had a love/hate
relationship with. When I pull a steak out of the freezer that's
frozen down to zero degrees, I'm happy. But when I don't need the
freezer, its a real annoyance to use 70 to 100 Amp-hours a day on the
system. And of course, one small leak and the whole system is down.
(This happened twice in 7 seasons, and both times was detected in home
port, not while traveling.)

If I were building my system now, I might consider having two systems
based on the new Danfoss compressors. While perhaps not the most
efficient in total, having two systems for the two boxes would give
more flexibility in case one is lost.

Danfoss is the "hermetic" sealed compressor your A/B is based on, and
is used in most of the smaller systems today. Of course, the units
have changed in the last 20 years, and each company has some "special
technology" that makes theirs the best. You might look over
www.rparts.com to get a free education about the components in use
today. They carry the latest Danfoss units and this will give you a
baseline to see if you're getting your money's worth from whichever
system you decide on.





Dick Behan wrote:


The 20-year-old Adler/Barbour unit on our Victory Tug has expired.
Can't complain about the service, but what do you cruisers out there
think about replacing it? Go with Adler/Barbour again, or is there a
more up-to-date technology (and product) you'd recommend as superior?
TIA.

Dick Behan
M/V ANNIE