On our last cruise we had two occurrences where the thin layer of frost on the Adler-Barbour evaporator plate disappeared over night on separate occasions. The ambient temperatures were not significantly different over the 4 weeks and the battery bank was in excellent shape with the monitor showing about the same state of charge and battery voltage every morning we awoke.
Here is my theory and I would love for others to comment:
Because we like a lot of ice with our beverages, and even though we can make our own ice in the freezer, for $2 a bag it is very convenient to have a 10 pound bag sitting in a plastic container in the fridge compartment (container keeps melted water from getting in fridge). On one occasion with the mystery defrosting, and possibly with the second (not 100% sure), we had considerably more than 10 pounds of ice in the fridge.
Isn't it likely that the excessive ice kept the fridge temp down and did not cause the compressor to run much, if at all, during the night when no one is opening the lid, there is no sun streaming in to heat the top surface, and the ambient air temp is obviously cooler than the daytime? If the evaporator is not being chilled below freezing periodically, I think a thin layer of frost would melt, even at say 35 degrees or so.
If that theory doesn't explain it, then I am at a loss. Ideas?
Duane Ising - Past Commodore (2011-2012)
s/v Diva Di
1999 Catalina 36 Hull #1777
Std rig; wing keel, M35B, Delta (45#)
Punta Gorda, FL
http://www.sailblogs.com/member/diva-di/
Duane, good logic. After the fridge cools down (after the first day of non-use) almost everyone over the years has said it runs LESS. So, if there's a big pail of cold ice in there, the thermostat will simply say "I'm fine" and tell the compressor to stay off until the temperature drops enough to start it up. Good thinkin'.
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Thanks, Stu.
While I consider myself very fortunate to have a spouse who loves cruising, she has a tendency to think that any little anomaly is indicative of a problem. There are times when that is really appropriate (shuttle booster O-rings for example), but not always.
Duane Ising - Past Commodore (2011-2012)
s/v Diva Di
1999 Catalina 36 Hull #1777
Std rig; wing keel, M35B, Delta (45#)
Punta Gorda, FL
http://www.sailblogs.com/member/diva-di/
Duane, off a recent trip we put a bag of ice in the fridge for drinks and it had a dramatic impact on how much the compressor ran. I also noticed that it appeared to have been defrosted and my hit on. The batteries was almost nill for a Fri-Sun trip.
Jim
SV Illusion
2000 Catalina 36 MKII
Dunedin, Florida
2000 C36 MKII 1825
Another thought: Having the evaporator clean is GOOD. It means more cooling is getting to the box, because the frost stops the cooling.
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
[QUOTE=stu jackson c34;20194]Another thought: Having the evaporator clean is GOOD. It means more cooling is getting to the box, because the frost stops the cooling.[/QUOTE]
You mean 2" of ice all around isn't a good thing :confused: :p
Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay
Jim, thanks for the further validation, although I couldn't quite understand part of it. BTW, we loved recently visiting your city of Dunedin - very quaint and enjoyable.
Stu, you are so right that the frost acts as an insulator, slowing down the transfer of heat from the box volume to the evaporator coils and refrigerant. That's how igloos work, right?
My admiral has now heard it from several others, so she accepts my theory and realizes the fridge is probably still working fine. Captains/husbands get no respect sometimes! ;)
Duane Ising - Past Commodore (2011-2012)
s/v Diva Di
1999 Catalina 36 Hull #1777
Std rig; wing keel, M35B, Delta (45#)
Punta Gorda, FL
http://www.sailblogs.com/member/diva-di/
Sometimes...:confused::o:D:eek:
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)