My refrigerator still uses R-12. What are my options?

[Coolerking]

For the record, 134a has zero ODP.
Marine refrigeration systems are the smallest of their kind, anywhere, period.
The guys I know in the HVAC industry that work on 10,000 ton+ units with suction side piping measured in FEET, laugh at our stuff, and cannot even imagine a 1/12th hp compressor.
The average skyscraper has many tousands of pounds of refrigerant in it.
Every can of computer cleaner/dustoff is 134a.
Also, not sure if you know, but the propane/butane is added to various azetropic refrigerants help with oil flow within the system.

[wsmurdoch]

Originally Posted by sfnz

ok.... heard enough.... go read the label on your WD40 or CRC can re propellant....each has roughly 3 times total fridge charge inside..... and as we know most boats have 1..2...3..4 or more cans on board and as we all know these cans are not marine rated or corrosion protected..... suggest you seriously rethink your misguided phobias re reefers.

I just looked at my two different cans of WD-40, a big one and a little one. They both say "Propellant: CO2" right beside the UPC code. My can of CRC 6-56 Multi-Purpose Lubricant says, "Contains Petroleum Distillates 64742-47-2, 64741-88-4, Butyl Stearate 123-95-5, Fatty Acid Ester 61791-48-8, and Carbon Dioxide 124-38-9" It looks like both use carbon dioxide as their propellant.

Even so, I bet both make a good flame thrower just like the burning cans of Right Guard we used to threaten each other with in the dorm.

[rbk]

Originally Posted by Coolerking

For the record, 134a has zero ODP.

Yes but it’s 1400 times more potent as a greenhouse gas than carbon dioxide. So to release one gram of 134 is equivalent to releasing 1.4kg of co2.

[Joe500]

Hello Richard, I've been slowly working off of your advice. I bought a sensorpush bluetooth temperature sensor so that I could record what's going on as well.Now that it is fall, the fridge may be working better. It cooled to 40F with an outside temperature of around 70F. You can see it in the attached graph. We arrived late at night on September 27th, took food and ice packs out of the cooler and put them in the fridge, and turned it on. In the evening of September 29th, we cleaned the condensor, first with a vacuum, which didn't work, and then with wet paper towels. Surprisingly the temperature in the fridge actually went up around then, from 43 degrees to 47 degrees by the next morning, I don't know why. Probably a day had gone by, the ice packs we had brought from home had melted, and the temperature was going to rise anyway.

I've been looking into replacing the fan as you suggested, but I have a number of questions:

(1)You recommended a fan with 80cfm airflow. I've been looking at 120mm fans, I was hoping to find a quiet one. I saw some with around 50 cfm.
https://www.bequiet.com/en/casefans/718 I don't see ones that reach 80cfm--this same brand has a high speed one that gives 73 cfm but is much louder. https://www.bequiet.com/en/casefans/720 Are any of these good?

(2)Most of these fans are 3 pin or 4 pin; My current fan just has a positive and a negative. I guess I need some kind of controller? If so, which? Or can I just wire the other pins so that the fan is always on at full speed somehow?

(3)How would I mount one of these computer fans? Looks like they have to be attached by the corners. As you can see in the photo, the current fan is mounted on one horizontal bar going across and in front of the condenser.

By the way, I took measurements with an IR thermometer. The condensor temperature was around 90F. The compressor was much hotter, if I recall correctly 124F. It was fairly hot in the entire area there probably high 80s--It is under the kitchen sink and closed off by a door under the sink that we open infrequently to access the garbage can hanging on that door. From reading Richard's website, I understand cabin air is supposed to move in and out of there. I guess along the line of Richard's suggestion, maybe I should leave the door open and see if that makes a difference.

Someone suggested using the IR thermometer to measure the copper tubes going into and out of the evaporator. I cannot access that as the entry seems to be towards the back of the evaporator.

Thanks in advance to Richard or anyone in the cruisersforum community that can provide further advice.

Regards,
Joe

Originally Posted by Richard Kollmann

Five amps per hour current for compressor and 0.8 amps for brush type condenser fan is normal for that age Frigoboat BD2.5 compressor system.

The correct R12 refrigerant charge by weight is 4.4 ounces. This type system’s cooling performance depends on precise volume of refrigerant plus or minus 20 grams. Ambient air temperature across condenser and condenser efficiency control whether volume of refrigerant is sufficient on this type capillary tube refrigerant system.

After looking at your picture of condensing unit I believe the condenser may be clogged with debris of dust and hair and the old inefficient fan motor should be replaced with a more efficient 4 inch 80 cfm muffin computer fan.

I suggest a non destructive test to determine if problem is condenser cooling or lack of refrigerant is the cause of poor performance. Vacuum what looks like blockage in lower half of condenser air fin coils. Then place any larger fan in the area blowing air towards condenser cooling fins for a 12 hour test. If performance is poorer than before and amperage is less system is low on refrigerant.

I do not recommend using any refrigerant other than Freon R12 if you are looking for extended life or maybe another twenty years. Yes there are many blended unfriendly replacement refrigerants but none as reliable as the original R12 mixed with wax free mineral oil in Danfoss BD 2.5 refrigerator compressor is the only good choice. Ask around and someone will give you a small 10 ounce can of R12.

Remember there is NO Drop in refrigerant to replace R12 refrigerant approved for the BD2.5 compressor.

[sdj]

Dumb question - is that condensor mounted hard against a flat wall with no airflow out the back of it? Also, the condensor looks a mite small from my experience...

It'd be dead trivial to put an ounce of propane in it..

[Joe500]

I'm not at the boat now, but I don't think there's much airflow behind the condensor. It's up against the wooden wall as you say. On the other side of that wall, is the U-shaped couch with dining table, and under the couch opposite the condensor is probably the hot water heater. So there probably isn't even a place to make a vent for the back of the condensor.

[sdj]

Originally Posted by Joe500

I'm not at the boat now, but I don't think there's much airflow behind the condensor. It's up against the wooden wall as you say. On the other side of that wall, is the U-shaped couch with dining table, and under the couch opposite the condensor is probably the hot water heater. So there probably isn't even a place to make a vent for the back of the condensor.

That, along with the small condenser, looks like a bad to me.

I do all my own refrigeration work, and if it were me I'd top it off with a tiny bit of propane and make those temperature graphs again. It's easy to do, and once you've done it once you will wonder what all the fuss was.

If you want to do this, you need any line with 1/4" flare fittings and an adapter for your gas bottle. Nothing else.

Connect the rig up with the bottle inverted and then crack a fitting at the fridge end and purge with propane for just a second to blow any air out. Leave the area to ventilate for a few minutes to allow the flammable gas to clear, or forcefully ventilate it. Tighten everything and start the fridge, open the service valve and then open the gas bottle for about two seconds and then shut it and close the service valve. Leave everything to run and see what the fridge does.

If you make a mistake and have gas everywhere, just close all valves and WALK smartly. Don't turn anything electrical off for God's sake...

[CapnJackB]

Your evaporator icing up is an indication of low refrigerant due to lower pressure in the system.

[Dougtiff]

If the evaporator is frosting over, more R12 is not needed, these systems use VERY little refrigerant, its easy to over charge, then you have a mess, my guess, is not enough insulation, and or poor gaskets, Hot Shot is a BAD product, do not use it, i am basing these comment's on many year's of doing refrigeration work, starting from designing, building and putting on line, insulate, insulate, insulate.

[Joe500]

It seems refrigeration is some kind of poorly understood magical phenomenon. Just in the last two messages, one response is that icing of the evaporator means low refrigerant whereas the next message says frosting over means that there is sufficient refrigerant. I bought the Kollman book and have been going through that.