propane. it has been around since Kriste was a corporal in the infantry.

It is possible to have refrigeration on your boat without running the
engine. Here is a basic design concept that will allow wind or solar
power to support onboard refrigerator.
1. The refrigerated box needs to have at least four inches of
encapsulated urethane insulation. The size of the box and the
temperature to be maintained inside the box will determine the daily
energy required.
2. The decision as to wind or solar for energy depends on anchoring
and cruising locations. Large heavy boats that like to anchor out
where there is more of a breeze might be better suited to wind power.
In South Florida Solar Power seems to be the preferred alternative
power.
3. There are only two small 12 volt compressors today that can be
efficiently adapted to wind or solar power, the Danfoss BD35 and BD50.
4. To take full advantage of the new Danfoss variable speed
efficiency with alternative energy, manual or automatic speed
switching controls are required.
5. It is also possible to save 3 to 6 amp-hrs per day in some cruising
areas with a keel cooler.

Here is an example of a system in a three cubic ft. box with four
inches of urethane insulation, with a planed cruising area of the
Bahamas:
The condensing unit would be a Danfoss BD35 compressor either a WAECO
85 or a Technautics Coolblue. If the Coolblue were selected which is a
holding plate system a voltage startup switch would be added This
switch would bypass the thermostat when a charge current was
available from any source exceeding 12.8 volts the compressor would
run.
Seventy five watts of un-shaded, adjustable solar panels is the
minimum requirement for this example.
Two additional gulf cart six volt batteries are needed to produce 12
volts and would be wired to solar panels and refrigeration unit.
Between the gulf cart bank and the house bank there is a Battery
Combiner to link them together when a charge current is available.
To complete the system a battery monitoring instrument is required.

There are several wiring diagrams of these systems in my 12/24 Volt
Refrigeration Manual

From the author of four books on boat refrigeration
http://www.kollmann-marine.com




"Skip Gundlach" wrote in
message ...
Hi, and thanks for the response.

"David&Joan" wrote in message
news:9i4Fc.6732$151.2942@fed1read02...
Skip:

Theoretical considerations aside, my advice would be to insulate your box
to
the hilt and then install one of the many DC driven Danfoss compressor
systems with a direct evaporator coil, ie no holding plate. Alder Barbour
and others make them.

David


Ah - now we get back to the discussion of evaporators and cold plates.
I've
just got this thing for cold plates - and ours is an Adler Barbour system -
but if evaporators worked well, and I felt comfortable about not having to
worry about dinging them, I suppose I'd be ok with them.

However, I'm still trying to come up with the most efficient overall
electrical plan which doesn't use internal combustion any more than
absolutely necessary. Stories of reefers running happily off the solar or
wind make me happy, because most of the time they wouldn't need the battery
during the day, which - at least in the high season - will be when we're
gone most of the time. Depending on how much they cost, a
belt-and-suspenders approach might be worthwhile to consider:

We're going to redo the reefer. It's 19CF, with cold plates added some
time
along the way, with a single hatch (see URL pix in sig), as originally laid
out as an icebox by Moorings, but divided so that a freezer section would
be
easy. When we redo the top to have two hatches, as it's so big, we'll add
insulation and some fancy ceramic paint which adds some amazing R value for
a coat of paint. It's plenty big to add some insulation material and leave
the current cold plates (engine and AC on one of them, both 26* units),
*and* add evaporator plates around the perimeters. I also intend micro
fans
(always on, in the bottoms) to move the air to even out the temps, and mega
gaskets and way-insulated tops as well. (I recall reading that the only
notable difference in the high-insulating coolers for the
picnic/camper/RV-tailgater crowd is an insulated vs not insulated lid, and
others in these fora and various mailing lists have cited the same in their
boxes' efficiency.)

Glenn was kind enough to give me a long dissertation on the merits of cold
plates and evaporators long ago in this space, so we don't need a
repetition, though others just joining the party might enjoy it/them. I'm
still of mixed mind. In the end, I want it to stay cold in the most
efficient manner. This will be our home, all year round, in the tropics,
so
doing it well is important. The specific means of achievement (cold plate,
evaporator or mix)isn't really important. Part of my challenge is, I
realize, a fetish about not running internal combustion motors if I can
avoid it, complicated by our expected lifestyle of working ashore with the
boat on a mooring for some months per year. I anticipate we'll have
awnings
and shades, but we won't run A/C, so it will be warm inside...

Thanks again for the input...

L8R

Skip and Lydia

--
Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"And then again, when you sit at the helm of your little ship on a
clear night, and gaze at the countless stars overhead, and realize
that you are quite alone on a great, wide sea, it is apt to occur to
you that in the general scheme of things you are merely an
insignificant speck on the surface of the ocean; and are not nearly
so important or as self-sufficient as you thought you were. Which is
an exceedingly wholesome thought, and one that may effect a
permanent change in your deportment that will be greatly appreciated
by your friends." - James S. Pitkin

In article ,
(JAXAshby) wrote:

propane. it has been around since Kriste was a corporal in the infantry.

and one should want an explosive gas onboard a sailboat, why?????

me

On Sun, 04 Jul 2004 00:05:55 GMT, something compelled Me
, to say:

In article ,
(JAXAshby) wrote:

propane. it has been around since Kriste was a corporal in the infantry.

and one should want an explosive gas onboard a sailboat, why?????

The electricity in the computer you're using to post to this
group has the potential of killing you, yet you use it. One
assumes that it's because you aren't sticking your fingers into
the power supply, or ****ing into the vents.

Propane isn't inherently dangerous, it just needs to be treated
with respect. A properly installed, maintained, and operated
propane system is safe. It's cost, availability, and ease of use
make it a very good source of heat in a boat.

Questions of safety with propane on boats have long been addressed. The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical. That makes them
great for RVs and maybe power boats but not for sailboats.
--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.

not true. unless the vehicle is NOT moving side to side.

On 04 Jul 2004 02:05:22 GMT, (JAXAshby) wrote:

The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.

not true. unless the vehicle is NOT moving side to side.

lateral forces mimic inclination.

you don't understand how the system works. please don't comment again.

The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.

not true. unless the vehicle is NOT moving side to side.

lateral forces mimic inclination.

You people seem to have missed two things in the thermodynamics part of
your education.

A Servel Cycle (the identifier for water/hydrogen/ammonia abortion
refrigeration) requires both the persistance of two liquid/vapor seals
and a lot of vertical room.

The vertical height is required so the ammonia can get condensed and
then be run down into the evaporator by gravity.

The two sealing loops separate a: ammonia vapor from ammonia liquid and
hydrogen and b: water from hydrogen.

The "household" units - these include RV - do not have seals that work
well out of vertical. Seals for these have been designed that do just
fine at a considerable offset. If the seals get blow out, they will
re-establish themselves with a reasonable amount of running time.

A one time I was employed by a company that was in the process of
developing a refrigeration system that could used the exhaust heat of an
RV to be the motivating heat for the refrigeration (apart from the fact
that the system had real flexability issues as far as installaion) the
whole program went down in flames whent he bottom fell out of the RV
market during the original Arab Oil Embargo.

Another issue for sailors would be that the COP (co-efficient of
performance - sort of the effieciency) of Servel units was not as good
as an R12 or R22 unit.

Matt Colie


Horace Brownbag wrote:
On 04 Jul 2004 02:05:22 GMT, (JAXAshby) wrote:


The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.

not true. unless the vehicle is NOT moving side to side.


lateral forces mimic inclination.

Jax, you are so full of BS. Norcold and Dometic both say that their
units should be level within 2º when parked and should never exceed 10º
while operating underway. Sloshing side to side does prevent pooling as
long as the tilting is fairly equal in both directions. Sailboats on
passage tend to remain on one tack, and therefore heel in one direction,
for several hours.

In short, when I asked tech support at both companies to recommend their
products for my boat they both said don't do it.

JAXAshby wrote:
The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.


not true. unless the vehicle is NOT moving side to side.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Jax, you are so full of BS.

not at all.

Norcold and Dometic both say that their
units should be level within 2º

----------------- when parked ----------------

and should never exceed 10º
while operating underway.

------------------ on a steady incline -------------

Sloshing side to side does prevent pooling as
long as the tilting is fairly equal in both directions.

nah. you just need enough motion to pitch the liquid inside back to more less
the vertical so it runs back to the burner.

Sailboats on
passage tend to remain on one tack, and therefore heel in one direction,
for several hours.

not part of the problem. see above.


In short, when I asked tech support at both companies to recommend their
products for my boat they both said don't do it.

neither guy knew how his system worked.

btw, propane reefers probably aren't right for extended usage tilted at angles
of 25* or higher, but damned few boats these days sail anything but poorly
tipped over that far. If you are going to be heeled over on you ear for a long
period of time, turn the reefer off.

gas absorbtion reefers need the burner as its lowest spot in the system. Tilt
them over too far and some turn in the system is lowest. shake the system
around by wave action (something RV's don't do while parked) the liquid gets
back to the burner. tilt the unit (as in a parked RV) too far and let the
burner run it will scorch the inside of the chamber and the system will no
longer work.


JAXAshby wrote:
The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.


not true. unless the vehicle is NOT moving side to side.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com