Fridge/Freezer Temperature

[denverd0n]

You still have not said whether this is a change, or if it has always been like this.

I'm also surprised that no one has mentioned insulation. Boat manufacturers are notorious for using the very least amount of insulation that they can get by with in their fridges and freezers. You can almost always improve your fridge/freezer's functionality--at the very least, reduce the energy it consumes--by improving the insulation.

Good luck.

[Richard Kollmann]

Originally Posted by stephanfeb

Hello

I have separate fridge and freezers installed onboard. My freezer is not keeping anything frozen, and because of it's location aboard (behind nav station), it's compressor is located in a poorly ventilated locker.
I purchased remote/wireless thermometers and monitored the fridge (not freezer). The lowest recorded temp on the fridge was 8 degrees celcius (45 Fahrenheit).

Before I embark on trying to "fix" things, I would like to know what typical achievable temperatures are for fridges and freezers aboard without massive reengineering effort. All help is much appreciated.

Both my fridge and freezer uses a coldplate (frigoboat).

Regards
Stephan
SV Andiamo II

The first thing you need to do is verify each one of the performance indicators:

1. Best condenser performance is with condenser cooling medium temperatures that can maintain temperature of compressor at less than 130 F. If your unit is air cooled air interring condenser should not exceed 90 degrees and warmed air should not passed through condenser a second time.
2. Is the line that leaves the condenser going to evaporator warmer than a persons body temperature?
3. With thermostats set to full cold for several hours check to see frosted areas for what has frost and what does not have frost. If system has correct amount of refrigerant there will be frost covering 90 % of evaporator’s surface area and no frost on return line outside refrigerator box on line going towards compressor. Describe frost you see.
4. If system has a fan cooled condenser is it free of dust and hair. If this is a water cooled system is the condenser or keel cooler free of insulating growth?
5. Is there condensation anywhere on box exterior? Does exterior of box feel cool?
6. Is there fast accumulation of condensation or frost inside box?
7. What number on dial is each thermostat set at and do compressors cycle off and on?
8. Do you believe these units run more than 50% of the time.

Each of the above answers can help to identify your performance problems and hopefully lead to simple corrective actions. A complete description or pictures of your Frigoboat systems would help.

Correct temperature for freezer will depend on desired storage life of food storage example, if transporting already frozen food temperature must be below 22 degrees F. The longer you want to maintain food taste the lower storage temperature must be. Desired recommended refrigerator temperature is 34 to 38 degrees F. Forty to 60 degrees is a drink cooler and not a refrigerator.

[Anna Sail]

[QUOTE=stephanfeb;1766679]
The next thing I noticed was that thick blocks of ice was forming around the exposed copper tubing for the refrigerant. I bought a length of fridge tube insulation and wrapped that around the copper tubing and "sparingly" secured my wrapping with duct tape . In spite of these efforts the temperature would still not go down.

Hi Stephan,
Has anyone added refrigerant to your freezer? "thick blocks of ice" on the copper tubing to the compressor could be a sign of an overcharge. The symptoms of an overcharged system can be the same as those of an undercharged system.

[Cowboy Sailer]

I was reading this thread and ran across a posting that was really good. It was spot on. I looked at the writer and it was Richard Kollmann. No wonder! I guess that I should read the author before I read the advice. Anyway, Richard, thank you for being a part of this forum.

[Xlantic]

Stephan, does this happen also happen when you are connected to shore power or only when cruising and on the hook?

If the latter, you could suspect excessive voltage drop in the wiring and connectors between the batteries and the refrigerator and freezer. These units tend to have a device that shuts them down if the voltage drops below a predetermined level.

Otherwise I would agree low refrigerant is a prime suspect as ice formation in the lines is common symptom of this problem.

[dohenyboy]

If the locker is poorly ventilated you could try adding an auxiliary fan to ventilate it better. Would be a cheap fix and worth a try


Why can't things remain where i carelessly left them?

[stephanfeb]

@DenverOn - It's an old boat circa 1985. It's difficult to tell if the freezer was done at factory or after market. I bought her (as third owner) with freezer already installed. The quality of the cabinetry done around the freezer would seem to indicate factory install. The one change that was made to the system is that the engine (belt) driven compressor has been disabled in favour of 12v refrigeration. I guess at some point I'll have to haul out and clean out all the crufty legacy bits that are non-functional.

@RichardKollman - Many thanks for the comments. The freezer is aircooled. However the compressor sits in a cabinet above the freezer. The door to the cabinet is slatted (louvers?). I am also worried about the ventilation in this area and how it might affect performance. I'll try to post some photos/video the next chance I get.

@AnnaSail I don't know that anyone has added refrigerant. Certainly not since I bought her. Then again, the freezer has never worked properly since purchase.

@Xlantic this problem persists irrespective of having her on shore power or not. I've left the freezer running for weeks on shore power to see what happens and temperature just never drops to acceptable levels.

@dohenyboy - thanks. I had a similar thought. Now I just have to figure out which bulkhead/panel gets the hole and how I explain said hole to SWMBO