Adding water cooling to Adler Barbour Supercold Machine

[Gary H]

Hi all,

I've got an AB SuperCold Machine on my Sabre 42 that was installed using air cooling only. I've had good results with it in Florida for shorter trips, probably due to the well-insulated box. The compressor averages about 10 hours run time out of every 24 with the thermostat set to my liking. I'm eventually going for a longer Caribbean cruise and am wondering if I should add a water pump for sea water cooling. Has anyone had experiences (good or bad) with this?

Also, if I opt for a pump other than the one sold with the kit, what flow rate should I be looking for?

Thanks in advance,
Gary

[Richard Kollmann]

As long as compressor/condensing unit is correctly installed on Adler Barbour units adding water cooling pump will not improve its performance. The only exception based on my tests is when seawater temperature is 60 to 75 degrees.

[Blue Stocking]

Richard,
I think a very important point that you have often stated is the increased danger of failure by polution of the refrigerant by water if electrolysis perforates the heat exchanger coil.
Don't ask how I learned this $900 lesson.

[Gary H]

Thanks for the info. I guess I'll continue to listen to the air cooling fan whirring away in the saloon. It's a loud little sucker.

[SimonV]

I too would like to add water cooling to my Danfoss, it did have it in the past but due to a corrosion problem causing a pin hole in the gas line I went with the air cooling only option. The quote for replacing the water cooling was astronomical being just shy of a replacement unit. I bet some one some where has a cheap fix for water cooling, with out degassing.

[DeepFrz]

Gary, you may be able to replace your fan with a quieter one. Also ducting the air to the fan and from the heat exchanger to the cabinet outlet may help the cooling a lot.

[Sumner]

Originally Posted by Richard Kollmann

As long as compressor/condensing unit is correctly installed on Adler Barbour units adding water cooling pump will not improve its performance. The only exception based on my tests is when seawater temperature is 60 to 75 degrees.

I also wondered if there are huge or even not-so-huge benefits to water cooling. I considered it, but didn't go with it and I don't think we will have any regrets.

We made and installed a rather small, about 4 cu. ft., fridge/freezer last spring in the boat while living and working on her up on stands in Florida. We stayed till the end of July when the humidity was very high and daytime temps were around 92-94, overnight lows of 77, and cabin temps in the high 80's.

We went with the more efficient of the two different Danfoss 35's, the 84, and I don't think it was even running 20% of the time. I'll have a more accurate run time when we go back and I put an hour meter on it.



The key in our case was lots of insulation. The whole build and specs for what we used is here....

Endeavour 37 Interion Mods Index

We probably won't ever get further down in the tropics than the Bahamas, but I'd feel comfortable with our fridge/freezer anywhere and don't think that water cooling and the complexity of it is warranted, at least not in our case.

As was mentioned getting air to and away from the compressor is important...



...and I tried to do what I could in that respect with multiple inlets to where it resides (one set above and also 2 other sets of inlets) along ....



....with shrouding the fan to get the hot air out. It is not loud at all and you have a hard time ever hearing it run,

Sum

[Celestialsailor]

Originally Posted by Gary H

Thanks for the info. I guess I'll continue to listen to the air cooling fan whirring away in the saloon. It's a loud little sucker.

Man!!!...ain't that the truth. I wish someone would come out with a quiet pancake fan.

[Gary H]

I think my problem IS the ducting. It's a 4 inch round outlet which seems to amplify the noise of the fan. The compressor itself is pretty quiet. I think I'm going to try cutting a larger, rectangular cooling duct that is roughly the size of the radiator to see if that quiets things down. At a minimum, it should improve the cooling efficiency.

[Sumner]

Originally Posted by Gary H

.I think I'm going to try cutting a larger, rectangular cooling duct that is roughly the size of the radiator to see if that quiets things down. .

Interior Mods page 10

Ours is very quiet with the larger opening. I have to bend over to actually hear if it is running.

Off to the right you can also see another group of inlet holes and there are more going back in under the starboard settee where the air should be cooler as the hull is in contact with the water there along with the other set that I posted further above in this thread,

Sum

[Celestialsailor]

Here is my set up. Under the galley stove.

[Cheechako]

I've had both, found little difference between the two. Just make sure your Air cooled unit can breath fresh air.

[Richard Kollmann]

When improving an icebox in a boat’s mobile refrigerator there are always difficult questions to answer like, type and how much insulation or should condenser be air or water cooled. Another question, what would be considered as a correctly install compressor condensing unit for best performance.

A boat refrigerator’s insulation is considered inadequate if insulation exterior temperature is more than 4 degrees colder than cabinet ambient air temperature when refrigerator has operated for a day or more. As mobile refrigerators are exposed to changing temperatures moisture in cabin air can penetrate and collect in open spaces of insulation. Any insulation that allows air to move in and out as compressor cycles off and on will act as a dehumidifier collecting water reducing insulation efficiency. Closed cell R 20 to R40 insulation is commonly used in mobile refrigeration. Even with closed cell material a complete moisture barrier is a good idea in boat refrigerators. Open cell insulation is used in heating industry and may not be suitable for refrigerators.

Correct way to install a compressor condensing unit is in a location where cooling medium air passes through condenser coil only one time. Cabin ambient air will provide a more stable refrigerant operating pressures than water cooling. Pictures posted by Sumner and Celestialsailor show two of the best ways to install small Danfoss compressor condensing units. Ambient cabin air is drawn from coolest part of cabin through condenser and and fan attempts to pressurize that compartment forcing warm air out holes where warm air rises away condenser inlet.. This warm air rises mixing with cabin air adding no more heat to cabin than heat of one person would on a warm day.

What about question of condenser fan noise?
There are two causes of fan noise with muffin fans, vibration and blade tip pulsating air sound. Vibration can sometimes be eliminated by placing soft washers between fan and condenser. Blade tip air noise can be absorbed by placing scraps of carpet to walls inside condensing unit compartment.

If I am building or improving refrigerator box what about toxic vapors from materials I use? Will these toxic vapors out gas over time causing health problems?
I am not qualified to answer questions about Air Quality of gases. I know that any place that sells materials must provide you with a Material Data Safety Sheet. Best you contact manufacturer of insulation and get MSDS paper on that insulation and other materials used.. As I recall material in air with a TLV of less than 100 will kill and over time, diesel fuel fumes with a TLV of 1000 is not good. I fond info on internet covering TLV:
Threshold Limit Values or TLVs are air quality standards developed by the American Conference of Governmental Industrial Hygienists. They are the model for many other air quality limits such as OSHA's permissible exposure limits (PELs).
TLVs are the amounts of chemicals in the air that almost all healthy adult workers are predicted to be able to tolerate without adverse effects.
There are three types:
• TLV-TWA (TLV-Time-Weighted Average) which is averaged over the normal eight-hour day/forty-hour work week. (Most TLVs.)
• TLV-STEL or Short Term Exposure Limits are 15 minute exposures that should not be exceeded for even an instant. It is not a stand alone value but is accompanied by the TLV-TWA. It indicates a higher exposure that can be tolerated for a short time without adverse effect as long as the total time weighted average is not exceded.
• TLV-C or Ceiling limits are the concentration that should not be exceeded during any part of the working exposure. Unless the initials "STEL" or "C" appear after "TLV", it is the eight-hour TLV-TWA that is meant.
TLVs are NOT "safe" limits. Even a few "healthy adult workers" will be unable to tolerate concentrations at the TLV.
TLVs also do not apply to people with certain health problems, allergies, people taking certain medications or drugs, people who work longer than eight hours per day, children or the fetus.
TLVs are not static - they change. They represent the current best estimates based on research. Make sure you have an up-to-date MSDS. Check the revision date.
TLVs are not available for all chemicals (There are ~700 TLVs. OSHA estimates there are over 650,000 chemicals in the workplace. Many have never been studied. Chemicals without TLVs or other exposure limits should NOT be considered safe.)
TLVs are used to assess workplace exposure by providing a comparison point for testing and to assist in product selection. When deciding which product to use, choose the chemical with the higher TLV so long as the chemical characteristics match your needs.
A lower TLV means less is allowed in the workplace air, and less you should inhale.
If you must use a chemical with a low TLV, make sure you plan adequate control measures (e.g., use in a chemical fume hood or with adequate local exhaust.) Make sure you arrange with EH&S for air monitoring if you suspect your exposure is not being adequately controlled.
TLV Measurement Units ContaminantUnitsUnit definition Dust, Fumes or Mist (solid particles)mg/m3Milligrams of contaminant per cubic meter of air. Gases and vaporsppmParts of contaminant per million parts of air.

[DeepFrz]

Quote from Richard Coleman:
What about question of condenser fan noise?
There are two causes of fan noise with muffin fans, vibration and blade tip pulsating air sound. Vibration can sometimes be eliminated by placing soft washers between fan and condenser. Blade tip air noise can be absorbed by placing scraps of carpet to walls inside condensing unit compartment.

There are also many new technology fans available. Some are DC motor some are 120 vac. These eliminate or reduce fan tip noise, cabinet noise and at the same time increase airflow. Many have better bearings than the typical muffin fan and a much higher lifespan. For instance ebm-Pabst offer fans with 50,000 hr. life expectancy. No idea what the price is but it will be higher than your typical noisy muffin fan.

[Celestialsailor]

Originally Posted by DeepFrz

There are also many new technology fans available. Some are DC motor some are 120 vac. These eliminate or reduce fan tip noise, cabinet noise and at the same time increase airflow. Many have better bearings than the typical muffin fan and a much higher lifespan. For instance ebm-Pabst offer fans with 50,000 hr. life expectancy. No idea what the price is but it will be higher than your typical noisy muffin fan.

Well if you happen to find some that will replace that muffin fan on the AB cold machine, let us know. That sucker is loud.