Fridges / Cold Boxes ?? Waeco

[Tranona]

For simplicity I shall be running mine on 12v all the time and when on shorepower the charger will more than keep up with the demand on the batteries. Engine has dedicated battery.

 

[lustyd]

Same for me, I can't see why I'd want the complexity of a separate power supply for the fridge, when the boat already has a 12V power supply through the charger. You could argue that the fridge will disrupt the fancy staging of modern chargers, but then literally everything on the 12V circuit will affect that.

 

[Chiara’s slave]

I fitted a compressor fridge to the ice box in my last boat. It ran on 12 volt supported by 240v when on shore power. 18 years in the Med and no problems. I have now moved to a smaller boat in the UK and have purchsed an Alpicool stand alone compressor fridge. I intend to run this on the 12 volt circuit backed up by 240v when on shore power, as with my last boat. My question is this; is it more effcient to run the Alpicool directly on shore power when alongside, or is there no advantage to leaving it connected to 12 volt with shore power replenishing the battery?

Hard to say. It depends on how efficient your battery charger is, and the youth of your batteries. There may be an efficiency rating on the fridge mains adapter, they are usually quite good these days. You won't notice the difference financially, if it's 10% different, that'll be a couple of quid a year maybe. Unless it's on 24/7. We don't have shore power, which saves us from such decisions. Ours manages on 12v with solar. The outboard does charge, but it's 10 mins at the beginning and end of a sail, barely worth the mention. We hardly ever motor anywhere.

 

[lustyd]

If you want to run your fridge 24 hours

Unless it's on 24/7

This is a weird thing to be saying. If you don't run your fridge all day it and the contents will get warm, and the gas will equalise. When you turn it back on it will run hard for a long time with the resultant power being about the same as leaving it on. The energy lost through the fridge walls is constant until the fridge warms up so the laws of thermodynamics are against you if you think you'll save power.

 

[Neeves]

If you want your fridge to be efficient, reduce the frequency of opening and shutting the door, in crease the insulation (commonly very difficult), increase the flow of fresh air to the compressor and warm air from the compressor (ie increase ventilation - computer fans and ducting). if you fridge is in a cupboard, add a vent to the door, attach a computer fan wired to the compressor.

Jonathan

 

[Chiara’s slave]

This is a weird thing to be saying. If you don't run your fridge all day it and the contents will get warm, and the gas will equalise. When you turn it back on it will run hard for a long time with the resultant power being about the same as leaving it on. The energy lost through the fridge walls is constant until the fridge warms up so the laws of thermodynamics are against you if you think you'll save power.

What I mean is running it like the one in your kitchen. I take it as read it’ll be on 100% of the time you’re on board. We clean ours out and turn it off when we park up and go home.

 

[Refueler]

We have the same issues, our fridge is under the companionway step( theres only 1). We have 120ah of battery, but it only has a 15hp outboard to crank, and if it can’t, there’s a hand start. 200w of solar currently, we plan on doubling that and going Li on the battery. We looked here Search Fridge | VEVOR EU and chose one that we could fit in. Obviously a rectangular box wastes space on a boat, you don’t get the capacity of a built in fridge. We manage, milk, salad, bit of meat and a few tinnies.

mmmmm like the look of the 40L version ..... once I get to boat when weather improves a bit ... will measure up.

I would still use my auto relay to switch on / off as engine is used - boat is a Motor Sailer - so engine is on more than many people would ... ie ~ 50% of trip time ?? That should give plenty of cooling time especially that compressor should on / off as temp varies.
Addition of Solar ?? I have looked at that for various reasons - but the matter is where to mount a panel ... I would need at least a 40 - 50W panel to get even a small amount of charge. The 'fridge' is rated at about 40W I think ... so that panel is not going to keep up with it ... panel now looks more like 120 - 150W ....
That's a big panel to mount on my boat .....

 

[Chiara’s slave]

Shame they've gone up since we bought. But still good value. They're nicely made and finished, quite solid. It takes a while to make ice in it, but the tonic gets satisfactorily cold.

 

[Refueler]

Shame they've gone up since we bought. But still good value. They're nicely made and finished, quite solid. It takes a while to make ice in it, but the tonic gets satisfactorily cold.

Bombay Saphire or Tanghueray with Tonic and slice of lemon ......

That'll do nicely !!

 

[Chiara’s slave]

The choice is almost limitless these days. We drink Wessex King Alfreds, because we race against the man that makes it.

 

[Refueler]

Mind keeps turning over ideas .....

The space where I put my Coolbox ... I could actually remove partially the remaining bunk base and build a box to drop a portable compressor job into ... I wouldn't build a fridge there ... but have a portable unit lift out.
It would lower the lid height ... allow me access to the space under cockpit bench that is usually blocked .....

mmmmmmm

 

[FairweatherDave]

I removed the chart table on my Konsort for my Dometic CDF 36
Providing you have a bit of solar top up / use your motor for your batteries the fridge won't drain your batteries at all unless you are into serious ice production

 

[Refueler]

I'm actually thinking to sink the fridge box into the bunk base as earlier posted - then hinge MAYBE a chart table above it !!

I know .... grand plans and all that.

 

[Tranona]

Doing something similar under a saloon bunk where I had the new cushion cut so I could lift half of it for access. large space with good ventilation through a disused hot air heater outlet.

Alpicool has just arrived courtesy of Amazon. will have a good look at it tomorrow to see whether I can duct it to the outlet maybe with a computer fan. Nice project (as if I did not have enough already!).

 

[LittleSister]

I recently saw adverts for 'Boo' brand fridges. Not a name I've come across before, but appear likely to be drop-in replacements for the very common Dometic/Waeco ones, plus a drawer fridge alternative.
Boo 12v and 24v fridge freezers

 

[Pete7]

I had one of these Alpicool compressor coolboxes - 20l, very good value indeed, worked well and drew not much power. If you're quick they're on Amazon ATM @ £178 minus £35 offer so only £143...

We have a 20L Alpicool too. Struggles a bit to achieve -20c in freezer mode so we run it at -15c which it is happier at and then keep a bath towel over it to assist the insulation. Works well in fridge mode and uses about the same as our existing fridge kit in a cool box.

Pete

 

[rotrax]

All last summer - May 22nd to September 16th - our two 12v DC built in refrigerator/freezers were on, one as a freezer set to minus 15C. The Dometic 40 litre was used as the overflow fridge.

400W of rigid solar using an Epever MPPT reg. kept everything charged.

Even after three rainy and dull days and dark nights the batteries never fell below 12.6V. They varied, depending on the amount of sunlight between 13.1 and 14.4 V. When the fridges kicked in, little voltage drop was noted. The freshwater pump however caused a threequarter volt drop.

In fact, the batteries have not been charged apart from using the engine on passage since the solar was installed on May 12th.

Here in NZ the cheaper compressor units have a good reputation.

IMHO the Dometic 40 litre is more efficient on 240V AC. It runs less.

Purely subjective, by observation, no scientific analysis.

 

[Chiara’s slave]

Subjectively, that suggests you’ve got a voltage drop.

 

[rotrax]

When current is being taken from the house bank I would be surprised if there was no drop.

In my more than 55 years of experience with vehicles using batteries, drawing current normally drops the voltage at the terminals.

 

[Chiara’s slave]

Of course it does. If you can see a difference like that, it suggests something over and above that norm.