Refrigeration - My big off season project

Rick D

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Jun 14, 2008
7,023
Hunter Legend 40.5 Shoreline Marina Long Beach CA
+1 SeaFrost. Replaced my AB ten years ago due to a tech ruining the compressor by filling with r134A. No bueno. The SeaFrost has been quiet and energy efficient. Of course, it's also newer.
 
Jan 18, 2016
696
Catalina 387 Dana Point
The Cool Blue units are very good. They're more expensive than an Isotherm, but the holding plate design is more efficient. Yup, you need to make the same amount of cold to cool down the box, but with a longer run time and a longer off time the efficiency goes up. (Holdover at night until the solar comes back up would also help)

I'd personally would not use a watercooled unit in saltwater. One more thing to corrode away, one more hole in the boat. The aircooled units are quite nearly as efficient, easier to install, and more reliable.

Some units are 110/12v (mine is) which is kinda nice for being at the marina I can turn the 12v systems completely off.
 

Blitz

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Jul 10, 2007
613
Seidelmann 34 Atlantic Highlands, NJ
I still have an AB system that is over 30 years old. It works fine but is air cooled with the extra fan but struggles in the best heat of the summer.

My next replacement would consider Isotherm SP Self-Pumping refrigeration system using their special thru-hull fitting with a built-in condenser/heat exchanger. Any plus or minus comments on these for the OP to consider?
 

CarlN

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Jan 4, 2009
578
Ketch 55 Bristol, RI
I have had great luck with the Frigoboat systems. They are efficient, cheaper than some, easy to install (pre-charged). The one on my current boat has been running for five years with no problems. For a 30ft boat that's not full time cruising, I'd get a simple to install air cooled system. It's recommended to change the o-rings on the quick connect fittings ever 5 years. This takes about 30 minutes and doesn't leak any gas. Upgrade it with the electronic thermostat.

I gort mine from Coastal Climate in Maryland. They've offered great support on the phone.

 
May 17, 2014
133
hunter 380 Plano, TX
I still have an AB system that is over 30 years old. It works fine but is air cooled with the extra fan but struggles in the best heat of the summer.

My next replacement would consider Isotherm SP Self-Pumping refrigeration system using their special thru-hull fitting with a built-in condenser/heat exchanger. Any plus or minus comments on these for the OP to consider?
The keel plate system is great in northern waters but from what I have heard they really struggle in southern waters especially if there is little flow over the plate. The high water temps kill the delta for discharge of heat. Think Gulf, Fl, and Caribbean
 
Jul 7, 2004
8,060
Hunter 30T Cheney, KS
It's alive! This original post was based on the premise that my compressor was bad as the seller told me. Well I downloaded NovaKool's troubleshooting tips and decided to check my system out as step one of this project. Turns out the compressor is fine. The thermostat is bad. I jumper the contacts for the t-stat on the AC controller and everything starts up fine. I have contacted NovaKool to order a new one. It's still the same old system but I should be able to get some years out of it for much less money than a full replacement.
 

MitchM

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Jan 20, 2005
964
Nauticat 321 pilothouse 32 Erie PA
I had a dial isotherm w a remote compressor that was OEM 2005 and works faultlessly. they have excellent customer service and human beings that will talk u thru the install.
 
Jul 7, 2004
8,060
Hunter 30T Cheney, KS
Nova Kool responded quickly. They confirmed that the t-stat they currently sell works with my 20+ year old system. Price including shipping is only $47. Great news considering I thought I was looking at a complete system replacement. I only have to install the stat, insert the temp probe in the evaporator, and run the cable to the control unit. Easy peasy. I'm guessing the Freon is fine since the compressor runs and I was told "it suddenly quit".
 
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Feb 2, 2006
453
Hunter Legend 35 Kingston
I installed a convertion model of Isotherm in my icebox a year ago. I would recommend evaluating and increasing the insulation to the box prior to figuring our your new system. If you end up installing rigid foam to the inside of the box your square footage will be less allowing for a smaller unit. Pay attention to sealing surfaces and lids/doors. I don't recommend the energy conservation module Isotherm offers. Went through 2 of them on instalation and aband
ed the idea.
Regarding the "energy Conservation" module, are you talking about the ITC Controller?
Chris
 
Feb 22, 2010
64
Oday 322 Delaware River
I installed a self-contained Isotherm unit a couple seasons ago. I am very happy with it. See my YouTube video on installation. Be sure to read the comments below the video for a discussion on amp usage and dip-switch settings for the control unit. Cheers.

 
Apr 8, 2010
1,641
Ericson Yachts Olson 34 28400 Portland OR
Nice 'slide show', and much appreciated. I installed a slightly different Isotherm model in our boat a couple years ago. Pretty much the same compressor. One comment about putting the fan & coils under the range -- that's were the stray tatters and onions and some grease splats can end up, and.... you may get a cut on your hand or wrist when cleaning stuff from that area. Misplaced spatula's end up there, too!
As long as the gimbals let it have the usual swing room you are fine.
I also have a little remote temperature sensor (wireless) and display at our nav desk. It's nice to know that the fridge is at 37 or 38 degrees without opening the lid all the time.
 
Jul 7, 2004
8,060
Hunter 30T Cheney, KS
Quick update on my progress. The new NovaKool thermostat installed fine. Compressor and thermostat come on now. Now I have to see why it's not cooling. One line should be hot and the other cold. I have a Freon issue so I just reached out to them for the proper way to recharge the system. I have gauges and a vacuum pump. Cold beer storage is almost in reach :beer:


How about those Chiefs! :clap:
 
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Jul 7, 2004
8,060
Hunter 30T Cheney, KS
Didn't get much help from Nova Kool on recharging my unit. Evidently my BD2,5 compressor has been superseded by the BD35, so all available info is for the 35. I only see one access port with a Schrader valve. Shouldn't there be a high and a low? I'd like to vacuum down this unit and recharge it. Do I do it all from this single port?.I've repaired auto A.C. systems but I'm far from an expert.
I'm determined to come out to a fridge with cold beer this season .
 
Jul 7, 2004
8,060
Hunter 30T Cheney, KS
Sigh. Nothing is simple on boats. My unit isn't cooling. I'm sure it's a refrigerant issue. There is some oily residue on the line with the drier. I am going to remove the compressor assembly and take it in to get a new drier installed and make sure the plumbing is leak free.
Nova Kool recommended that I replace it all with a.newer unit for around $1k. It kinda makes sense for an almost 30 year old system but I can get this one working again for a lot less. Power consumption isn't an issue because we will be on shore power. I have the evacuation pump and gauges. It comes out this weekend and I'll get a local assessment of this compressor.
 
Oct 22, 2014
16,440
CAL 35 Cruiser moored EVERETT WA
I can get this one working again for a lot less
Sure you can. And with the Pandemic conditions you have the time to fiddle. Thus expanding you knowledge of boat refrigeration. It is a big win win.

Just "Go for It".
 
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Jul 7, 2004
8,060
Hunter 30T Cheney, KS
Final update....I hope. The HVAC guy came out yesterday to complete the reinstallation. He bench checked it first to see if it was even worth attempting it. We had the green light so we dropped it back in, soldered the lines to bypass the leaky connections, installed a new dryer, evacuated and recharged the system.
It's working great so far. We stayed over last night and everything is still chillin'. Total cost was $250.
Still no guarantee how long it will last.He said it was tight, the valves are fine. It was money well spent if I get a few years out of it. I calculated the draw while running. It's about 65 watts. Just a whisper from under the settee.
 
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Dec 29, 2008
798
Treworgy 65' Custom Steel Pilothouse Staysail Ketch St. Croix, Virgin Islands
SeaFrost gets my vote. Did the same upgrade 2 years ago, removing the old 110V Grunert compressor and holding plates with the 12V SeaFrost. Uses very little power, soft start, quiet. Comes precharged. The cooling plates are customs made to your size requirements.