Trawler fridge and freezer power option

[Offthehook]

Ok, so im 12 months in to the refurbishment of my Tradewinds 44, I have decide to keep the existing built in freezer and refrigerator, do I change the existing refrigeration unit (located in the engine room)out for a 12 volt unit? Do I keep the original unit and run on an invertor? (New 240V refrigeration unit fitted prior to me purchasing the trawler). I believe the fridge is about 90 litre, the freezer around 60 litre ,anyone done anything similar or have other thoughts, trying to get total piece and quiet without the genny running, thanks

 

[DavidM]

In general, 12v compressor based refrigerators ( the Danfoss based units) are more efficient than 120V refrigerators. The efficient 120V Energy Star refrigerators get close but still take 1.5 times more power than a 12V system. Standard 120V refrigerators are even worse.

If you have lots of house battery capacity, maybe 400 Ahs and a good way to recharge them- a genset driving a 100 amp charger, then you can get by with this poor efficiency. Otherwise replace them with 12V Danfoss systems.

David

 

[Offthehook]

trawler fridge and freezer power option

thanks for your spin on the subject David, I think now I will go with a 12v Waeco CU-94 compressor condenser unit, I will send the supplier an email to see if this will be sufficient to run both my fridge and freezer..

 

[FF]

The key to electric fridges is fantastic insulation, and seals.

A simple test is to empty the fridge and stick in a big block of ice , wait a day and remove the ice and use a Very accurate scale weigh it.

Stick the block ice back in and wait 2 more days , and then weigh it again..

Send the weight loss to who ever will be sizing the system so they can know the BTU inflow per day.

As a quickie Rule of Thumb , under 5 lbs a day ice loss can be handled with a good DC setup.