MattK1969
Member
Fridges! My fridge is consuming a vast amount of power on my 1989 Malo 116. I expect that there is minimal insulation installed. Had anyone ever looked into this or done anything about it? Thanks from Aalborg.
Fridge energy use
- Thread starter MattK1969
- Start date
Neeves
Well-known member
Data?
What do you mean by 'vast amounts of power'?
Jonathan
What do you mean by 'vast amounts of power'?
Jonathan
Stemar
Well-known member
Is it a compressor type, or a gas/electric absorption one? Compressor types are far more efficient.
johnalison
Well-known member
I would be asking: is the compressor unit in good condition and fully gassed?, is the cold box adequately insulated?, and what setting do you leave it on?. My 2000 unit seems to work without straining the system. We usually have it set to about 3-4/10 but turn it down to 1 when away from mains power, when we can last for five days or more with around 200 a/hr available.
MattK1969
Member
It's a compressor. It's been overfilled with Freeon I have realised, as it's sweating, but probably won't help. Sorting a bit at a time until it stops sweating.
MattK1969
Member
Good question, it's running all the time at the moment. The batteries show a 1v drop when it's running. Not sure I can add more!
Neeves
Well-known member
madabouttheboat
Well-known member
What age is it? Newer fridges tend to be much more efficient.
vyv_cox
Well-known member
As Jonathan says, measuring the current is a good clue. When my fridge compressor Danfoss BD35F starts its cycle it draws about 4 amps. This declines over the run to about 3 amps at the end. Typically in Greece it runs for about 10 minutes and is off for about 20 minutes. The fridge is a 55 litre standard front opening unit with a custom water-cooled condenser.
Neeves
Well-known member
MattK - there are ways to make refrigeration more efficient, they tend to be easy and cheap. There are other ways, which are more expensive 
.
But if you fridge is running 24 hours, so its not cycling on and off (as Vyv describes), then maybe your fridge needs some maintenance.
Jonathan
. But if you fridge is running 24 hours, so its not cycling on and off (as Vyv describes), then maybe your fridge needs some maintenance.
Jonathan
MattK1969
Member
Old! Probably 30 years
MattK1969
Member
I think I have identified the main problem. The fridge has been over gassed during recent maintenance. Removing some gas has really improved things.MattK - there are ways to make refrigeration more efficient, they tend to be easy and cheap. There are other ways, which are more expensive
But if you fridge is running 24 hours, so its not cycling on and off (as Vyv describes), then maybe your fridge needs some maintenance.
Jonathan
MikeBz
Well-known member
On this subject, we have an Isotherm 5000W which is seawater cooled (not keel cooled). When the compressor runs it draws 14-15A :-o - which seems rather high. I don’t have any documentation and can’t find any info online, other than an installation and service manual on manualzz.com which doesn’t help.
Neeves
Well-known member
Can you disconnect the seawater cooling, for a short time, to identify what the seawater cooling draws and separately what the fridge draws. I'm assuming the 14/15 amps is after the maintenance - (was this by a professional refrigeration engineer?) - did he not check the current draw and make comment?
Jonathan
Jonathan
vyv_cox
Well-known member
My seawater cooled fridge uses a Par Max 1 pump running on 6 volts via an Isotherm reducer. It consumes less than 0.5 A, as of course it is not generating any pressure
Sandy
Well-known member
How much stuff do you have in your fridge and how cold was it when you put in there?
At the start of big trip I fill mine with frozen stuff then turn it on.
MikeBz
Well-known member
I will need to investigate - I suspect the pump is well buried under the battery compartment. I haven’t had it looked at, I commented on it to the previous owner said it was normal. He had a fridge engineer in quite recently with a view to replacing it with something more modern and was told “you don’t want to get rid of that, it’s a very good fridge”.
Neeves
Well-known member
I had a quick glance at fridges like, but not the same as, yours and they seemed perfectly adequate. Not being able to find 'your' exact model did make we wonder how big yours was and whether it had a big freezer compartment? I wondered also about the sea water cooling pump as being the possible different feature to many other fridges.
The amps needed to run your fridge are about 5-7 times what would be expected on most yacht fridges but they would be about 60l/80l in size (maybe have a tiny freezer box), use 5 amps when on but cycle on and off maybe using an average of 2 or 3amps/hr - as defined by Vyv.
Jonathan
Supertramp
Well-known member
Mine is 35 years old and draws current just as Vy Cox described. Never touched it.
I would make two initial checks. First is it pulling the fridge down to a proper temperature and keeping frozen food/ice as ice in its freezer box? If it is at the right temperature then find and check the temperature sensor that should then trip it off when it's reached set point.
It sounds to me like it's not making enough cold. Is Freeon the right refrigerant? I seem to recall that the old refrigerants could not just be substituted with new?
I would make two initial checks. First is it pulling the fridge down to a proper temperature and keeping frozen food/ice as ice in its freezer box? If it is at the right temperature then find and check the temperature sensor that should then trip it off when it's reached set point.
It sounds to me like it's not making enough cold. Is Freeon the right refrigerant? I seem to recall that the old refrigerants could not just be substituted with new?
MikeBz
Well-known member
There is no freezer compartment. There are 2 settings, “Auto” and “Freeze” - they only affect the duty cycle not the consumption when it is running. The duty cycle seems to be around 20-30% (auto) though I haven’t paid that much attention yet - the boat is new to us this year and this isn’t top of the priority list, but thought it worth mentioning here in case anyone else had the same piece of kit.
