DIY refrigeration and repair

[Vino the Dog]

Anyone have experience in repairing your own refrigeration or building one? Please share your knowledge.

[Cruisingscotts]

I looked into it and it's kind of a wash. You could build something with non marine brand components and get similar efficiancies with a basic process controler and good kw managment, but finding someone who will sell you a minimum order of one is about impossible. I found a very good price on vacuum panels but it was min $1000 for a run. By the time you add up all the materials cost for a smaller setup its not really worth it. If you had some crazy needs IE belt driven recip and huge freezer vs, hermetic compressor then maybe. Maintaining it is sort of the same, you really don't want to lug around a recovery unit, recovery cyclinder, charging cylinder gauge set, scale etc. Its a good idea to educate yourself on the basics and there is a chance a local HVAC contarctor will have classes. Getting your EPA universal technician card is not expensive but I don't think the material has not been updated since 1996 so not sure what it's worth. A simple class and your universal card will give you enough to be able to troubleshoot a small unit and add charge if nessesary.

[bstreep]

The card is $25. Open book test.

We've rebuilt much of ours, it's a Grunert Passagemaker.


Sent from my iPad using Cruisers Sailing Forum

[RaymondR]

What you do depends to a large degree on the size of your boat and how much effort you want to put into it.


I have a couple of acquaintances whose boats were large enough to have ordinary domestic refrigerators in the galley and since they spent most of their time in marinas they got by quiet well.


My own boat is not very large and required a refrigerator to be built in to make the best use of available room. The box I built myself from 3" polyurethane foam which I fibre glassed over. I installed a small eutectic tank and a Danfoss BD35 compressor and condenser unit. It worked well for about 7 years until the compressor seized up.


I then rebuilt it using one of those pre-charged kits consisting of a compressor/condenser unit and a plate which you mount in the box. the piping has connectors which retain the refrigerant until you connect them up. It was fairly easy to install and worked well for about five years however the copper piping is very thin in the evaporator units and prone to pin holes from corrosion.


I am now rebuilding using the compressor from the kit and a eutectic tank I am building to go in the box. I am rebuilding it as a eutectic unit even though it uses only a small 12V compressor to allow the best use of the solar power my panels produce. The eutectic tank will hold the box over during the night hours when the panels do not produce any electrical power. In this manner I hope to extend the life of my house batteries.


If you are a DIY sort of person and like learning new skills and tend to experience lasting gratification you create yourself, and like to be able to maintain your boats equipment yourself learning refrigeration is a excellent aspiration.


I found that Nigel Calder's Refrigeration For Pleasure Boats provided a lot of information however it is more aimed towards engine driven eutectic systems than the constant cycling 12V systems used in boats.

[Cruisingscotts]

I would add if you are lucky enough to have a small vendor close to you they can probably design and put together a system that with proper maintinace will last for a very long time. You can eliminate pretty much the only leak source in a med sized hermetic unit by not having the quick connect check fittings to connect the evaporator. The vendor will be happy to show you how to check and charge your system. If you do a search on here for "Richard Kollman" he is a regular contributor with lots of good advice as well as free info on his website. Be very careful of people giving you "I did this and it worked great" stuff as it is extremely easy to kill small units. The vendor should know boats and DC systems and be willing to answer questions. There are still places out there so you can shop around.

[wsmurdoch]

In 2004 I bought a boat with a non-functioning engine driven refrigeration system with a cold plate and a separate 125V condensing unit that used the same cold plate. Using the information in Richard Kollmann's two books and his excellent web site and advice, I repaired the engine driven system and have maintained both systems since. We have made nine trips from NC to the Bahamas enjoying frozen food, ice, and cold beer.

Kollmann Marine

Nigel Calder's "Refrigeration For Pleasure Boats" is also good but a little technical. Richard Kollmann's books are more like what a craftsman would tell his apprentice. Both are a little dated. It is really time for a new book on the subject.

[SURV69]

PELTIER ...

no one likes them, everyone hates the power it takes to run them, and they won't freeze ice cream ... generally.

4 to 7 amps per hour to run, but simplicity redefined if you have the juice to do it. Generally cools an insulated area to 30 or so degrees below ambient ... maybe more with good insulation and more yet if one uses the higher powered units(5-6 Amps per hour)

I had a Coleman unit to which I added a second fan inside and increased the inside insulation with about 1" foam and everything stayed really, really cold .... once it got cold. I used this for about 4 years and was very satisfied ... once, in July(not a real hot day, mind you), I froze a 1/2 gallon(maybe a quart), of milk to completely rock-hard frozen, like a brick. A fluke? I'm sure, but nonetheless ... solid frozen.

I usually ran the units for a few hours in the early(cool), mornings, reduced my access during the hot day(to reduce loss of cool), ran it an hour or two in the evening, and ran it again around midnight for a few hours ... tried to keep run time to about 1/2 time overall to make my total usage for 24 hours at 50%. About 4-5 Amps per hour for 8 or so hours for a total of about 30-40 amps.

Running the peltier unit during the hot part of the day is self-defeating, and the cooling of the peltier on a 90-100 degree day would actually mean you could be "heating", the contents ... that's why I never ran it during the day. Often, I would spray the hot heat-sink with water to help it keep cool ... always had a spray-bottle for this purpose.

Now ... I like milk, and I like milk near icy cold ... so cold that it's too cold to guzzle ... this peltier would make that milk, that cold ... consistantly.

If one wanted a "cooler", similar to an ice chest, that keeps things "cool", not "cold", I venture to say, the run time on a peltier unit could be further reduced. If you built a unit that took ice(where the melt wouldn't be a problem), to give the peltier a kick, you might further reduce your actual run time to a point where a decent-sized solar panel will give you enough juice to run the unit.

In any case, given the inefficiency of a peltier, and the lack of truly cold contents, the cost is ridiculously minimal, enough parts can be carried in a small bag for a few complete rebuilds(at a truly minimal cost).

It's not a Frigoboat(which I have on my newer boat), but with lots of insulation and a minimally invasive(?) way of getting things out(during the hot day), I think it would be worth a consideration ... for the right needs and the right frame of mind.

Any negative posts about peltier, are probably completely true, but I think Peltiers have a place for the right situation ...

... absolute simplicity
... absolutely cheap
... better than nothing(if a real unit is too much $$)

[Rhapsody-NS27]

I just wanted to share this link. I think it's one of the best fridge refit projects I've seen.
http://www.cruisersforum.com/forums/...dge-76345.html

[a64pilot]

Repair, certainly, I think that is almost as necessary a skill as being a competent Diesel mechanic. I have my card, carry gauges but not recovery equipment.
Build your own? Not me, not that I couldn't but I wouldn't want to, very similar to building your own watermaker, I think I could but by the time I got one as reliable and as efficient as one I could buy, I would have at least 100's of hours in it, probably spend twice as much too, but I believe I need to be able to repair one.

[ColdEH]

I built my own condensing unit. I had to teach myself HVAC or basically just enough to understand what is going on inside these mysterious systems . I posted the build with the pitfalls I encountered in this thread.

http://www.cruisersforum.com/forums/...te-162911.html

I originally started by just repairing my system but decided to re-engineer it after learning a few things.

It was a fun process and I will be doing it again shortly for my deep freeze.

Regards

[conachair]

Originally Posted by Vino the Dog

Anyone have experience in repairing your own refrigeration or building one? Please share your knowledge.

Slightly relevant, I replaced a bust thermostat with an arduino, a couple of years later it's not missed a beat once.
http://www.cruisersforum.com/forums/...nt-124511.html

[rubbywilliams]

You just need to find some reliable expert rather than trying own your own when you don't have the experience.

[ErikFinn]

Originally Posted by rubbywilliams

You just need to find some reliable expert rather than trying own your own when you don't have the experience.

Many people on this forum are folks cruising in remote locations and prefer to be self sufficient in their fridge maintenance. If not self sufficient then at least aspiring to become one. It can be extremely rewarding to learn your systems aboard a yacht and be able to repair them.

There are many stories about "experts" destroying a good system so even if one could find an "expert" in some remote location chances are the result will end up in lost time and money. An "expert" experienced in domestic fridges does not necessarily know how to remedy a marine system. Although not overly complicated, but different.

I have learnt so much reading this forum I am ever so grateful to all the knowledgeable people here willing to share their experience and knowledge, and welcome threads such as this, and will read with great interest and enthusiasm.

[ColdEH]

Originally Posted by conachair

Slightly relevant, I replaced a bust thermostat with an arduino, a couple of years later it's not missed a beat once.
http://www.cruisersforum.com/forums/...nt-124511.html

I use a STC 1000 thermostat to control my fridge and my furnace/hot water heater and soon my freezer .

STC-1000: Temperature Controllers | eBay

They are so cheap I bought 10 to keep back ups . I have 4 in service as I speak and have had no failures .

Works great , I have the sensor half way up the inside of the box and hold the box temperatures between 2 and 4 degrees Celsius.

I am using a thermostatic expansion valve to control the plate not a fixed orifice or capillary , so no chance of over powering the plate .

Regards

[ErikFinn]

Originally Posted by typhoon

I use a STC 1000 thermostat to control my fridge and my furnace/hot water heater and soon my freezer .

STC-1000: Temperature Controllers | eBay

They are so cheap I bought 10 to keep back ups . I have 4 in service as I speak and have had no failures .

Works great , I have the sensor half way up the inside of the box and hold the box temperatures between 2 and 4 degrees Celsius.

I am using a thermostatic expansion valve to control the plate not a fixed orifice or capillary , so no chance of over powering the plate .

Regards

I really like your setup, and read your thread.
What's the difference in between a 10 dollar Digital Thermostat and a 200 dollar one?

STC-1000: Temperature Controllers | eBay

RPARTS.COM - Digital Thermostat

Carel Digital Thermostat & Sensor