Waeco CF-40 Coolfreeze compressor fridge freezer

[Ian_Edwards]

Hi,
I thinking of using a Waeco CF-40 Coolfreeze compressor fridge freezer as a freezer. The boat already has an adequate compressor driven fridge, but I can't find a sensible place to build-in a freeze.

Since I've now formally retired (as opposed to being retired but still actually working part time) I'll be taking longer trips and really need a freezer because I intend to cruise in some of the remoter parts of the Scottish Western Isles.

I'm aware that the compressor driven fridge freezers are quiet and efficient, but has anyone used one in freezer mode, say -8 to -10 degC over long periods of time (weeks)?

This is obsequiously going to use more power than the 5 deg C Waeco quote in the spec' sheet, but how much more?

Finally are there any better alternative to the Waeco?

 

[FirstAway]

I have a CF-18 which I normally use just as a fridge, and occasionally turn it right down (up?) to work as a freezer. I am not sure exactly how this increases the running time of the compressor but it is a lot and really drains the battery.

I think the only answer to efficient operation is insulation and certainly the construction of the CF-18 makes it difficult to box it in as the compressor and heat exchanger are integral. If I did it again I would go for a seperate compressor unit.

 

[philip_stevens]

Hi,
I thinking of using a Waeco CF-40 Coolfreeze compressor fridge freezer as a freezer. The boat already has an adequate compressor driven fridge, but I can't find a sensible place to build-in a freeze.

Since I've now formally retired (as opposed to being retired but still actually working part time) I'll be taking longer trips and really need a freezer because I intend to cruise in some of the remoter parts of the Scottish Western Isles.

I'm aware that the compressor driven fridge freezers are quiet and efficient, but has anyone used one in freezer mode, say -8 to -10 degC over long periods of time (weeks)?

This is obsequiously going to use more power than the 5 deg C Waeco quote in the spec' sheet, but how much more?

Finally are there any better alternative to the Waeco?

I've got a Waeco CF30 (I think that is the size) on our boat as an addition to the compressor driven cool-box. We have used it as a freezer, but with 3 x 110W batteries, 60W solar panel, and Rutland 503 wind genny, we have not experienced any real problem.

To better insulate the coolbox, you can get an insulated jacket to go around it, and also an extension box to go on top to act as a cool-box - getting its cooling from the Waeco.

 

[Deefor]

When I had my CF-45, it was always used as a freezer.

In some ambient conditions, it wouldn't freeze past -2 deg C. But then I fitted a small 12v computer fan on the outside of the casing where the grille/air inlet is. By "forcing" ambient air over the compressor, I got it down to -18 deg C and the box seemed to be more efficient.

But boy did it eat into my 2 x 100ah batteries - no more than 24 hours before the low voltage safety circuit on the box cut in.

 

[Ian_Edwards]

Some calculations - but are they correct?

Thanks for the replies so far, the boat has 400amp hr of domestic batteries, a 115amp alternator, 30amp shore power battery charger and a 40watt solar panel, so there's a fair amount of stored power and the ability to recharge.

I've looked at the Waeco data for the CF40:

It say 45 watts, which I take to be the rating of the compressor, so with a nominal 12volt system, that's 3.75amps

It also states 0.83amp hr /hr for an ambient of +32 deg C and an inside temp of +5, that's a temperature difference of 27 deg C and the compressor running 22.1% of the time.
and
0.68amp hr/hr for an ambient temperature of +20 deg C and an inside temp of +5, that's a temperature difference of 15 deg c and the compressor running for 18.1% of the time.

To me there doesn't seem to be enough difference between the two, I'd have thought that it would be a lot harder to keep things cool at +32, than +20.

If I simply take the temperature differences (and I'm not sure how valid this is), and assume a ambient of +15 (north of Scotland on a good day!), then in the 1st case that would give me an inside temperature of -12 deg C and in the second case 0 deg C.

So if I assume a 20% duty cycle, which should get me in the right ball park for temperature, I get 18 amp hr per day (3.75x24x0.2), which doesn't seem to be a lot and doesn't tally with the reports from this forum.

Am I making a silly mistake?

 

[Deefor]

Ian, my CF45 went back to Waeco three times in three years, twice out of the guarantee period, cos it wouldn't cool down to < 3 degC when on 240V. When moored up for a few days to shorepower, the mains circuit would cut out and revert to 12v without me noticing. The next thing I knew was that it drew so much power that it cut out and ruined the contents on several occasions.

They replaced various electronics but each time it failed to cool. Hence I fitted the 12v fan and it worked as it should have done from day one. To me, the compressor was overheating due to lack of air flow when being asked to freeze rather than cool but Waeco failed to see this, stating that many others worked fine .

TBH, it was the first and last time I'll buy Waeco and I think for the price their gaer is over rated.

Sorry, JMO .