Seafrost Upgrade Recommendations

[Sabreman]

I have a leaking 1980's vintage engine-driven Seafrost Refrig unit that uses R-12 refrigerant. It's never worked since I've owned the boat. We tried to charge it last year with an R-12 replacement, and it worked for a while, but lost the refrigerant due top leaks (probably at the compressor). The questions to the forum are:

Should I -
1. Replace the compressor & hoses (~$400) with a new R-12 compressor and hope that it's not leaking anywhere else (a sniffer indicates that the leak is only in the compressor so I think that the rest is ok) and pay big $$ for R-12 ($200?) to charge it?
2. Bite the bullet and buy an R-134 Upgrade kit from Seafrost (~$1500) and fagetaboutit for 10 years?
3. Switch off to a 12 VDC unit (Seafrost says that I'd need to upgrade my alternator & batteries)?

Opinions? Guidance? http://www.sailnet.com/forums/images...s/confused.gif

[trantor12020]

I'm surprise R12 is still available. I'm currently working on installing a 12V refridgerator. Saw my friend's boat came with it and it works so I guess I should be able to get mine working. Day temp here is 31C and evening 28C.

[RXBOT]

This is right up her line of expertise.

[svsirius]

It depends how you use the boat. We are full time cruisers with a 12v Seafrost system and love it. Like it better than our old holding plate system as it keeps the box at a constant temp rather than cycling up and down with the cold plate charges. However we have the battery bank to support it. I would look at it as on overall design question. Do you plan on upgrading the battery/charging system in general at some point if so this may be a good excuse to bit that bullet off as well. If not then stay with an engine driven system and make your life easier.

[speciald]

I'm a belt and suspenders type of guy. I have an engine driven compressor + a 110 water cooled compressor. The water cooled unit is more efficient but willshut down if the water intake gets clogged. Found this out this Summer when I left the boat in a slip for two weeks while visiting family. What was that smell ? - I asked my self when I returned to the boat. It was about $500 worth of defrosted freezer contents.

[camaraderie]

Sabreman: A little more info please...
1. What is your typical use...weekends & vacations or more often?
2. What is th size of your alternator and battery bank. Also what kind of dockside charger?
3. What is the present system...cold plate or evaporator type?
4. What is the size of the box and is it a fridge only or separate freezer/fridge?
5. Are you plugged into a dock most often or on a mooring.

[Sabreman]

cam, answers are in CAPS

1. What is your typical use...weekends & vacations or more often? WEEKENDS & VACATIONS
2. What is th size of your alternator and battery bank. Also what kind of dockside charger?
NOT SURE - STOCK ALTERNATOR ON WESTERBEKE 33;
NOT SURE OF BATTERY SIZE (I'M NOT NEAR THEM RIGHT NOW), EITHER Group 27 OR 31;
XANTREX TRUECHARGE 20 CHARGER
3. What is the present system...cold plate or evaporator type?
EVAPORATOR WITH A LARGE ALUMINUM BLOCK THAT FREEZES
4. What is the size of the box and is it a fridge only or separate freezer/fridge?
BOX IS ABOUT 6CUFT
FRIDGE ONLY
5. Are you plugged into a dock most often or on a mooring.
GENERALLY ONLY PLUGGED IN WHEN WE'RE ON BOARD

The "Admiral" recommends just pulling the whole system off the boat and staying with ice cubes & blocks since they worked fine for weekends and vacations on our last Sabre. I'm of the mind that we have a system that I'd like to get working if possible. It's also good for resale if we ever sell the boat (unlikely in the near term)

[deniseO30]

If you get just a condensing unit you should be able to use the old evaporator/cold plate. There are condensers that run 12/120 and switch automatically. You will of course need to do some upgrading on the 12 volt system as others have said. Old stuff is just what you have, old. Not really worth the cost to keep it running, unless you have the ability to do it yourself. There are lots of upgrade DIY condenser evaporator units available. I like norcold myself. Air cooled is the easiest to install but it may not work so well in really hot weather. Try to go with a cold plate type. They stay cold for days on end just like a block of ice. The same type system is used in big trucks trailers

Saber, where is the leak on the compressor? What was the R-12 replacement you used? 134 can work with the old condenser. But the oil is the problem, it's not compatible with 134. You would have to do the same thing that's done on older cars using 12. remove flush charge, flush. and add the new oil Of course the leak/s need to be found. you will need all the usual refrigeration tools of course.

my "good old boat" Oday 30 still has the old seafrost evap in the box, the condenser is long gone. I'll stay with ice myself. We've been on the boat 4-6 days in summer and with the box and a large cooler full of ice we were good to go! maybe someday I'll toy around with a new condenser, but not now.

[camaraderie]

OK...thanks for the additional info. My advice would be to replace everything with just a basic DC unit since your needs are modest and this is the cheapest way to go. I am a BIG fan of the Seafrost BD system
http://www.seafrost.com/bd.htm but it is not the cheapest one out there at about $1350. You can get a Waeco/Adler Barbour Cold Machine unit sufficient for your needs for less than $1000 with your choice of evaporator or cold plate.

No R12 new compressors may be sold today...so that is not an option. Your fridge guy MAY be able to purge your old lines and cold plate of R12 and install a new compressor with R134a refrigerant...but that is time consuming and expensive and if you are reasonably handy you do a whole new install for less. (It is not at all difficult ).

As to your batteries/alternator.
1. A new fridge unit will "cost" you about 60AH's a day which means that you need 120AH's of battery capacity JUST for the refrigeration and with a stock alternator as your only at anchor charge source..this means about 2 hours of running the engine daily for your fridge needs....+ whatever else you use.
2. It is unclear from your post what your total house bank AH capacity is...but I would suggest 300AH's or so should be sufficient for both refrigeration and general house needs for our casual usages. I do NOT suggest investing in a larger alternator/regulator as that is a big bill for a little use.
3. The Truecharge20 will take about 15 hours to 100% charge a 300 amp battery bank that has been 50% depleted. Suggest you leave it plugged in when not on the boat. otherwise it is likely you are fully charging your batteries only when you spend the weekend at the dock.

Hope this is helpful to you.

[Sabreman]

Denise/Cam, Thanks for the very helpful info. Using what Denise wrote, I'm wondering if I can simply buy a 134 compressor, hoses, RECEIVER FILTER DRYER (RFD), and SUCTION PRESSURE UNIT (SPU), and maybe a Valve unit per the Seafrost schematic diagram (http://www.seafrost.com/ED.htm). My cold plate/block is good, the condenser is clean, and I'm even wondering if I can use the existing RFD & SPU. I'd have it charged by a professional; I'd just do the installation. Pricing it out comes to $742 vs ~1500 for the entire R12 to 134 kit. The cost differential is too great to ignore. I don't see why I'd need a new plate and condenser. Opinions?

Cam, Seafrost does sell R12 compressors as follows: http://www.seafrost.com/edr12parts.htm

Thanks for the suggestions - this is what makes these forums so great.