That is a WHOLE different creature. With refrigeration you are trying to
dump a few hundred BTUs an hour. With engine cooling you are dumping a few
hundred BTUs a MINUTE. Lead is not the greatest heat conductor so you will
need a lot more surface area than a bare tube condenser. It will be hard to
bury that much and still keep the lead structurally sound.

With my small diameter tube I am not to worried about the bond but I will
sand blast the whole bolt frame/condenser assembly and paint the tubing with
an acid flux formulated for tinning copper pots. I found that the
copper/nickel wets out much better with it than regular acid solder flux.

I wired the tubes in place with .032 316L stainless wire. Not ideal but I
end up with a lot of 6' lengths every time I change from 316 to mild steel
wire on my MIG welder so I figure to put it to some use.

--
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

"Hess cutter 56" wrote in message
oups.com...
I was planning to use pipe cast into the keel to cool the engine.!
{A Sabb 22hp}. The Keel cooler that came with the engine is 10' long
5/8 tubing My keel will be a long rectangle. Aprox. 10' x 15"x 15"
. Glenn do you plan to use some type of flux on the tubing , Before
casting the lead ? And what type of wire do plan to use , To hold the
tubing in place Thanks CW

The down side of casting a condenser in the keel is that it is an extremely
permanent installation. No way to fix it once it is done so I added one
extra loop. If one of the working loops springs a leak I can just switch
over to the spare. I have had them pressurized with nitrogen to 250pis for
3 months now so hopefully they will not leak once they are inside the lead.

The loops are a continuous downward slope so the oil will pool right at the
return end. Probably could have made it a bit more efficient with a larger
OD tube to slow the refrigerant down, get more surface area and less
pressure drop but I read so much about oil getting trapped in the condenser
and starving the compressors that I got scared.

--
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

"Matt Colie" wrote in message
...
Glenn,
If it is a condensor, then the liquid refrigerant should carry the oil
along and should not pool in the turns of the coil (notice please the
"shoulds"). But I like th idea as you have it because:
-You have separate turns so a damaged turn could be eliminated from the
circuit.
-You may decide to rework the refrigation to be reversable and so provide
heat from the pond at little cost.

Just be sure that you keep the keep above freezing in fresh water. If
this idea appeals to you, you migth think of putting a little loop like a
trap at the outlet end just before the lift so the oil has someplace to
collect a form a big enough plug so it gets lifted out of the cooler.

Sounds interesting - I'd love to hear how it works out.

Matt Colie ex reefer guy (among the rest)


Glenn Ashmore wrote:
"Matt Colie" wrote in message
...

Glenn,
Are you planning to us this as an evaporator?
Matt Colie


No. It will be the condenser. The evaporator goes in the refrigerator.
The keel will be cold enough already. :-)

On Fri, 10 Mar 2006 13:23:26 -0500, "Glenn Ashmore"
wrote:
The loops are a continuous downward slope so the oil will pool right at the
return end. Probably could have made it a bit more efficient with a larger
OD tube to slow the refrigerant down, get more surface area and less
pressure drop but I read so much about oil getting trapped in the condenser
and starving the compressors that I got scared.

Glenn, did you give any thought to circulating water through the keel,
and then using that to cool the condenser? That would allow you to
use a combination air and water cooled condensing unit, and if
anything went wrong with the keel loop (and I'm concerned that it
will), at least you have the air cooling as a backup.

The idea was to avoid the circulating pump. If the whole thing craps out I
can always add a couple of conventional tube-in tube condensers and pull
seawater off the sea chest. I plan to keep the vacuum pump, extra
refrigerant and HVAC tools on board. Should be good for a few free beers
from fixing systems on other boats if I ever get down island. :-)

--
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

"Wayne.B" wrote in message
news
On Fri, 10 Mar 2006 13:23:26 -0500, "Glenn Ashmore"
wrote:
The loops are a continuous downward slope so the oil will pool right at
the
return end. Probably could have made it a bit more efficient with a
larger
OD tube to slow the refrigerant down, get more surface area and less
pressure drop but I read so much about oil getting trapped in the
condenser
and starving the compressors that I got scared.

Glenn, did you give any thought to circulating water through the keel,
and then using that to cool the condenser? That would allow you to
use a combination air and water cooled condensing unit, and if
anything went wrong with the keel loop (and I'm concerned that it
will), at least you have the air cooling as a backup.

Thanks Glenn That makes sense ! CW

Glenn, Your in the keel cooler will work fine, it should also work on
the hard if that side of the keel is not in direct sunlight all day.
Don't forget that these compressors without fan cooling depend only
on super-cooled refrigerant as the main source of compressor heat
removal, so if the compressors are located in a tight area supplemental
cooling is required especially in tropical climates. Frigoboat has now
added a small heat sink to compressors connected to their keel cooler
compressors but I don't think it is large enough to do any good in
the tropics.

Dick

Thanks Richard. I feel a lot more comfortable knowing you pass on the idea.
I am worried about compressor cooling too. I have two BD50s mounted on an
aluminum skid at the bottom of a locker. That is a mighty enclosed space.
The control units have those dinky little fans that come with the
compressors but I believe I am going to add a duct fan to draw air up from
floor level, blow it over the compressors and exhaust it under the galley
cabinets. Keep my toes warm while I am cooking. :-).

--
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

wrote in message
oups.com...
Glenn, Your in the keel cooler will work fine, it should also work on
the hard if that side of the keel is not in direct sunlight all day.
Don't forget that these compressors without fan cooling depend only
on super-cooled refrigerant as the main source of compressor heat
removal, so if the compressors are located in a tight area supplemental
cooling is required especially in tropical climates. Frigoboat has now
added a small heat sink to compressors connected to their keel cooler
compressors but I don't think it is large enough to do any good in
the tropics.

Dick

BD Module selection

Danfoss offers a series of special electronic modules for their 12 volt
BD35 BD50 compressor to address differant installation and operating
problems. There are two different modules to hopefully address the
radio noise problem, A soft start module for the BD50, An AC/DC model
to eliminate the battery charger when connected to shore power and
Danfoss's automatic speed control model. Unfortunately they don't
sell one model that has all of these functions. For more information on
this see the current post on my forum at http://www.kollmann-marine.com

Glenn, I would recommend the automatic speed control module described
by Danfoss as Adaptive Energy Optimization module (AEO). Here are
some additional recommendations:
· These units are so quite I would add a green 12 volt LED to the
module's unused fan terminals small + and F.
· All these modules have a chip inside for troubleshooting if a 12
volt low amp LED is connected to module terminals small + and D. A red
LED is recommended here as the only time it will be on is when there is
a problem.
· If you need to add a supplemental cooling fan I would control it
with a inexpensive temperature Snap Disc Control switch available from
WW Granger. I have used there model 2E246, fan turns on at 120 degrees
and off at 110 degrees the objective is to keep the compressors below
130 degrees F if possable, cost $7.

Richard, I would definitely prefer the AEO module but have not found anyone
selling them. R-Parts got a few in and immediately sold out. I even
considered programming my own microcontroller to adjust a digital pot in the
thermostat line to control the speed but decided it would take a lot more
R&D than I wanted to invest. If I find a couple in the future I will swap
out the originals. I figure a couple of spare power modules might rescue
somebody down island one day. :-)

I do plan to add the indicator LEDs. Saw that in the instruction sheet and
wonder why everyone doesn't do it. Thanks for the idea about the thermal
switch. That will definitely go in the system. The exhaust fan will be
buried behind the galley cabinets so it won't make much noise but no reason
to use amps when they are not needed. Think I will stick one on top of each
compressor and wire them in parallel so that if either needs more air the
fan comes on.

Heard so many stories about RFI from these power modules that I am going to
great lengths to suppress it. Lined the compressor compartment with copper
bug screen, adding chokes to the power lines and running all the signal
lines in shielded twisted pair. Hopefully that will help.

--
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

wrote in message
ups.com...
BD Module selection

Danfoss offers a series of special electronic modules for their 12 volt
BD35 BD50 compressor to address differant installation and operating
problems. There are two different modules to hopefully address the
radio noise problem, A soft start module for the BD50, An AC/DC model
to eliminate the battery charger when connected to shore power and
Danfoss's automatic speed control model. Unfortunately they don't
sell one model that has all of these functions. For more information on
this see the current post on my forum at http://www.kollmann-marine.com

Glenn, I would recommend the automatic speed control module described
by Danfoss as Adaptive Energy Optimization module (AEO). Here are
some additional recommendations:
· These units are so quite I would add a green 12 volt LED to the
module's unused fan terminals small + and F.
· All these modules have a chip inside for troubleshooting if a 12
volt low amp LED is connected to module terminals small + and D. A red
LED is recommended here as the only time it will be on is when there is
a problem.
· If you need to add a supplemental cooling fan I would control it
with a inexpensive temperature Snap Disc Control switch available from
WW Granger. I have used there model 2E246, fan turns on at 120 degrees
and off at 110 degrees the objective is to keep the compressors below
130 degrees F if possable, cost $7.

I was present during 105 degree ambient tests of the AEO in freezers
and was impressed with its performance but if you can not find them,
the next best thing is a Frigoboat SSC. I have one on my test bench
and it performs much like the AEO even adjusts for day night economy.
The SSC also has the LED built in including six differant speed LEDs.
There are a series of tests on the SSC in my 12/24 volt book. The BD50
will require a soft start feature if operated at max RPM in a warm
climate, both of these controllers have soft start features.
Dick