Fridge Reduce Amps Consuption

[Cheechako]

My friends sailed the pacific with the unit shown on the left. They loved it.

[stevensuf]

Now, is it cheaper to add an extra solar panel than to keel cool a fridge?

[SPARK]

If you are cruising and need to haul the boat for lengthy repairs and still live aboard on the hard, then sea water cooling won't work.
Just something else to think about.

[cat man do]

Originally Posted by foolishsailor

Another hole in the boat? Is it that much more efficient?

Build a seachest
Install cooling unit in seachest

[foolishsailor]

Originally Posted by cat man do

Build a seachest
Install cooling unit in seachest

Seachest? Not familiar with this term/concept, please elaborate?

[cat man do]

Originally Posted by Richard Kollmann

When someone asks me about water cooling instead of air cooling one of these systems with a Danfoss BD compressor I recommend against it because in many cases it produces an unreliable and maybe less efficient system than a well designed air cooled system.

In hot tropical areas whats cooler, sitting in front of a fan or sitting in the water?

I would think in most cases the fan is the cooler option as the water near the surface is about the same as air temp .

[cat man do]

Originally Posted by foolishsailor

Seachest? Not familiar with this term/concept, please elaborate?

Basically a manifold of sorts
A box with the top opening (clear acrylic) above the waterline.
At one end of the box is your inlet, below waterline.
then a dividing screen/filter
at the other end of the box can be several outlets.

SEDATION 4 - Miscellaneous

[Ex-Calif]

Originally Posted by cat man do

In hot tropical areas whats cooler, sitting in front of a fan or sitting in the water?

I would think in most cases the fan is the cooler option as the water near the surface is about the same as air temp .

In the equatorial regions definitely the water.

Humidity kills the human cooling aperatus...

[s/v Jedi]

A fan on sweaty skin = evaporation so it feels cold but that doesn't work for cooling down compressed refrigerant. Water cooled is about 60% more efficient even if water is the same temperature as the air.

Sea water pump is high maintenance and a big risk for sinking the boat if anything around it fails. It also draws power.

The Frigoboat keel coolers eliminate both negatives: they consume no power and they do not pose a risk (yes there is a hole in the hull, but a big chunk of bronze closes it off).

Outside the tropics I might opt for air cooled. When you cruise in the tropics you do not want extra heat sources in your boat.

Richard hates these, mainly because of some problems with them which I never had (leaking refrigerant). I think there has been a bad badge of the keel coolers. Mine have operated 100% for about 7 years now.

I have made a mistake by not painting them for many years. Paint them. Do not ground them.

The Frigoboat systems have a problem: there should be a filter-drier between the compressor and the evaporator. You should add one there.

On the hard you can keep using the fridge with the keel cooler. The air provides enough cooling. Last time I managed to keep running the freezer too. The trick was to provide a miniature plant sprinkler:


ciao!
Nick.

[senormechanico]

Nick,
I can see painting the keel cooler, but why not ground it?
The only reason I imagine it's recommended that it be grounded is if there's an electric leak from the compressor to case which would put the keel cooler above ground potential. If it's grounded to B- and the bonding system or zinc, it would not be damaged by electrolysis.

What do you think?

BTW, I looked at a photo of a leaking keel cooler posted somewhere in Richard's site.
By zooming in on the photo, the two refrigerant lines coming out of the cooler had obviously been spliced with poor soldering.
The leak was coming from the splice.

[CarlF]

Jedi

My Frigoboat keel coolers are grounded and not painted. I thought that was the recommended route? They've been working great but I'd like to keep them that way.

Carl

[Richard Kollmann]

S/V Jedi, I do not hate Keel Coolers but I do question the trend by boaters to believe a Danfoss BD variable speed 12/24 volt compressor should use water as a more reliable cooling medium than air. Opinions are based on facts, your seven years of satisfied performance and good service from a keel cooler is great and I am sure there are many others that have the same good experiences with keel coolers. Having testified in HVACR litigations I offer one piece of advice, follow instructions provided by manufacture regarding any water cooled condenser installation instructions.

In the last fifteen years we have seen many new products come alone promising more reliable and better performing refrigeration, some have worked but many do not live up to the buyer’s expectations. I keep a library of boat refrigeration equipment problems and solutions that I use for material for my books. I also have a boat refrigeration forum to answer questions on the subject. Kollmann-Marine

The following are a few of the boat refrigeration trouble items I am tracking:
· Through hull condenser cleaning problems.

· Danfoss BD compressor current leakage causing electrolysis damage on all water cooled refrigeration systems.

· Seawater condenser and keel cooler failures.

· Affects of water cooling on System Coefficient Of Performance especially on variable speed compressors.

· Danfoss BD compressor and module cooling without assisted fan cooling.

· Insulation R value requirements for boat refrigeration.

· Cabinet refrigerator problems in hot climates.

· Bad experiences with Vacuum insulation Panels.

· Radio interference caused by boat’s refrigerator


· Aero Quip self piercing pre-charged line connectors leaking at time of assembly that result in poor system performance.


· Problems created when using replacement refrigerants


· SeaFrost engine drive expansion valve screen blockage problems.

· York, Tecumseh and Climate Control engine driven compressor failures.

· Failure of couplings between motor and direct drive 12 volt refrigeration compressor.
· Electrical problems inside Adler Barbour stainless steel wiring box.

· Danfoss three and four pin module failures.

· If there is a life limit to a air cooled Danfoss BD condensing unit what would it be 20, 25, or life of the boat?

[senormechanico]

Richard,
I have your book and recommend it.
The reasons I replaced my system with a keel cooler were several, one of which was the air cooled condenser rusted out and lost the charge. It was the original system installed in 1995.
We repaired it a couple of times, but when the Admiral wants new...

[Cheechako]

I like the simplicity of the Frigo keel cooled unit. No fan, No pump. No heat into the boat. Many fan cooled units work just fine.... if you have a way of extracting the heat, they are a good choice too. It's a good point about whether you can using while sitting on the hard though.
Hey Richard...I dont see any facts... just a list... is there a point to your list above? Do you have # of occurances of each problem etc? The trouble prone units I've had were engine drive and big belt drive. I've oft wondererd about the use of the Aeroquip "connect and go" connectors though....

[s/v Jedi]

Richard, I can agree with every point on your list. Just wish you would agree that boats on/near the equator do not like to add heat to interiors and for those a keel cooler can be a better option than air cooled.

ciao!
Nick.