3 way V 12v compressor fridges

Pudsey Bear

Pudsey Bear

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I imagine any 3 way fridge no matter what you did would have struggled with our recent heat wave but how would a 12v compressor fridge have managed though, and just how much kit would you need to cope with it?
 
My three way fridge has worked happily in much hotter weather than we saw last week. It has three vent fans on the outside and one circulation fan on the inside.
A compressor fridge should work well enough, but use a bit more power when it's hot.
The problem is that many three-way fridges are very badly fitted and don't let the heat out easily.
 
My big 3 way a few vans back had the larger upper vent L300 I think and it did work whatever the weather but these older under the counter ones seem rubbish even if the sun isn't that hot with or without fans.
 
Pudsey Bear said:
I imagine any 3 way fridge no matter what you did would have struggled with our recent heat wave but how would a 12v compressor fridge have managed though, and just how much kit would you need to cope with it?
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Something that is rarely mentioned but is a key thing in terms of effectiveness and cost of running between the two ....

An Absorption Fridge, such as all 3-way units are, takes a long time to get down to operating temperature - usually overnight as a minimum during which it is burning gas all the time, or if on hookup, using around 200W+ constantly.
A Compressor Fridge is not just more efficient in the use of electricity, but will get down to operating temperature within a few hours.
This is an example - actually my own fridge just after I installed just a year ago showng the temp sensor in the Freezer compartment....
1660834086167.png

The difference here for people who may be just weekend campers for example is that they don't need to switch on the fridge the day before to make sure it is ready for use, but just in the morning when they get up. And because it is so much faster to get down to temp, you can even get away with loading it up while it is still cooling down if you are heading away soon after getting up - and your food will remain safe (safer!) just in the same way it would when you buy it in the supermarket and drive home with it in the car in shopping bags.

With a compressor fridge you will be using 2 days of electricity at around 60W a quarter of the time (around 850Wh including initial period).
With a 3-way, using either 3 days of gas around 80% of the time; or 2 days of gas around 50% or more of the time plus about 4kWh on hookup while it cooled down to operating temp.


And if you are someone that likes to just get up and go when the fancy takes you for random overnight camping trips, you don't have to plan that spontaneity 24 hours in advance ;)
 
Thanks Mr Bus, what would you need to have to run it without going OTT, my battery is 100ah panel is 85w and at opposite ends of the van, I'd prefer a 12v one rather than mains.
 
Pudsey Bear said:
Thanks Mr Bus, what would you need to have to run it without going OTT, my battery is 100ah panel is 85w and at opposite ends of the van, I'd prefer a 12v one rather than mains.
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I will give you the example of my VW T5 Campervan I built and used to go to VW Festivals to trade at.
Set the scene:
Arrive on a Friday (occ. Thurs) and depart Sun Afternoon. This was UK summertime, but in Scotland/North England so not overly blessed with sunshine on a typical weekend.
Van had a pair of 100Ah Lead Batteries; plus 200W of Solar. Fridge was a 12V Weaco CRX50 Fridge with freezer compartment.
I did have an inverter fitted, but not for the Fridge. I used to use it to power an induction hob to boil the kettle for cuppas in the afternoon as despite the fridge left to its own devices (so still on overnight at normal settings) the batteries were usually full by around 11AM and the solar harvesting was going to waste. Better using the otherwise wasted solar energy than burning gas!
When I left the shows on Sunday Afternoon, I had the same battery levels as when I arrived on Friday afternoon.
If I had 100Ah of batteries it would have been the same situation - full again by 11AM each day

In the summer, you can (and I did) leave the fridge on 24/7 because there is no reason not to in terms of power use if you have solar and reasonably decent days. I would recommend 200Ah of batteries however to give a buffer against poor harvesting on consecutive days.
I would also recommend upping your solar as why not if you have roof space! You can use the same cabling so no need to make more holes in the roof. Might need a slightly bigger controller though? Or maybe just invest in a portable solar panel to use alongside the roof one? nice and easy, and maybe more effective as you can point and angle it? (I have 270W on my roof but also have a 100W portable panel)
 
Hmm, I Thank you again

I forget what the current controller can handle, but I do have another 85w panel sat twiddling its thumbs in the old garage, I'd probably buy another pair of batteries if needed but would see how the present one did first. I do have another MPPT controller hiding somewhere too but I forget its capacity as I haven't even seen it since we moved here 4 years ago.

The OP was basically so I have some sort of answers for when the 3 way decides to pack up and Liz starts going on about not being able to trust it yet again, bearing in mind as far as working goes it's only not once in the last year and that was on 240v on the sloping drive it got hot in the chimley but didn't cool and no amount of mansplaining helped to allay the grief I was getting, so we have to freeze blocks at home and then carry a bloody useless dumb coolbox around.
 
wildebus said:
In the summer, you can (and I did) leave the fridge on 24/7 because there is no reason not to in terms of power use if you have solar and reasonably decent days. I would recommend 200Ah of batteries however to give a buffer against poor harvesting on consecutive days.
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What about the winter David?

Regards,
Del
 
wildebus said:
Depends on how you use your van (hence my comment about startup efficiency) and how the batteries get recharged.
Might need to top up the battery just like you need to refill the LPG.
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We're full time so our large 3 way fridge runs 24/7, it doesn't seem to use that much gas to be fair but I'm thinking that when it finally gives up will a 12v compressor be the answer because I've already got solar and lithium :unsure:

Regards,
Del
 
Okay, can give me experience on this one over the last four and a half years all year round in the U.K.

My compressor fridge is a Waeco 110ltr with freezer compartment inside at the top. Manufacturer says it averages 48Ah per 24 hours, think that ties in well with the new 50litre models using 24Ah over a 24 hour period. Lot less power needed for smaller fridge if it will serve your needs.

I have 2 x 100Ah Lifepo4 battery’s, 2 x 150W solar panels flat on the roof each going to its own mppt controller plus 100W folding panel I can put out when solar not as good. 1 x 30amp B2B which obviously helps when moving but useless static. 2 x 30 amp smart chargers for if I need to use the generator.

Weather isn’t constant but best guess is for seven months of the year in the U.K. I have no problems. As I can stay parked up for a couple of weeks or so at a time for the other five months I run the generator every couple of days to get the battery SoC back to 80%. I killed 3x90Ah Bosch PowerFrame battery’s in 12 months simply because I couldn’t keep them charged up which is why I bought the genny.

My fridge is on 24/7 for most of the year, it’s usually only off when I want to defrost it for a day. I did try about 6 weeks without it over last winter after all my mates saying you don’t need one in cold weather. I freeze a lot of chicken for the dogs and can keep my veg fresh easily two weeks in the fridge, I found it a pain throwing stuff out as it was well past it’s best even shopping every few days so won’t be turning it off again.

Performance in the heatwaves this year. My fridge control goes from 0 to 10, it is a little under 2 and has been all summer, everything stayed well frozen and anything I took out the fridge nice and chilly. I don’t have temperature gauges to say what’s what but it definitely works better than the fridge in the house. Saying that I don’t have milk in drinks and don’t drink beer so my fridge is probably opened less than a lot of other folks 👍

If/when my fridge packs up I will more than likely go for a domestic 230V replacement as so much cheaper than any kind of van fridges and I already have the infrastructure
 
To be honest I'd say for the bulk of folks...
3 way is old redundant tech if they've got a decent solar set up....

Compressor types win out ALL ways around in summer/warm weather.

Only winter does a gas fridge make even vague sense...
And even then its borderline IF you move around a fair bit.

One of my best moments was ripping the 3 way out and replacing it with, a, 240v undercounter that fit in the same space...

More useable space inside
Far less pfaff
No gas usage
No wind blowing it out
No worrying about it being level enough

Just great IMHO
 
What about night time noise levels if/when they kick in?
 
mistericeman said:
To be honest I'd say for the bulk of folks...
3 way is old redundant tech if they've got a decent solar set up....

Compressor types win out ALL ways around in summer/warm weather.

Only winter does a gas fridge make even vague sense...
And even then its borderline IF you move around a fair bit.

One of my best moments was ripping the 3 way out and replacing it with, a, 240v undercounter that fit in the same space...

More useable space inside
Far less pfaff
No gas usage
No wind blowing it out
No worrying about it being level enough

Just great IMHO
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Ill second that .
 
Pudsey Bear said:
What about night time noise levels if/when they kick in?
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lots of people say they would not have a compressor fridge as they are noisy.
Now the people who actually DO have them don't report any disturbance (and I don't think that is 'buyers regret' kicking in and pretending).

Of the ones I have had,
The 12V Waeco Coolbox was silent.
The 12V Waeco CRX-50 was silent, but I did used to feel a slight 'kick' around 5AM or so in bed when the compressor came on. It was not noise, but the jolt of the compressor transmitting through the bench seat/bed. Could have eliminated that if I could be bothered, but wasn't worth it.
The 240V Inventor Fridge was totally silent. The only way I knew it was running was to open the door and see if the light came on (the Fridge woke up the Inverter to run the compressor when needed, so when compressor off, light stayed off). I think everyone who has bought the Inventor Fridges for their campers have been happy with them.
My current 240V LEC Fridge/Freezer that replaced the Thetford 3-way is also totally silent and again I open the door if I want to check if it is running or not (as Fridge temp dictates if fridge gets power to run).

However .... I have a new Hoover Fridge-Freezer in the house and THAT, when running, makes some unusual sounds. It is in the kitchen so doesn't greatly matter, but I could imagine that unit might be annoying in a Motorhome?
 
Ive ran a waeco 110ltr compressor fridge freezer for nearlly 10 years now and never had a prob with running out of power and even more so now as ive 590watts of solar and 400amps of lithium .When i first fitted it ihad a 140watt solar and 2 x 125amp lead acid .Noise wise i use to hear it but not now .If i was doing an other build i woundnt hesitate in fitting a compressor fridge.
PS its all free electricity from now on .
 
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wildebus said:
lots of people say they would not have a compressor fridge as they are noisy.
Now the people who actually DO have them don't report any disturbance (and I don't think that is 'buyers regret' kicking in and pretending).

Of the ones I have had,
The 12V Waeco Coolbox was silent.
The 12V Waeco CRX-50 was silent, but I did used to feel a slight 'kick' around 5AM or so in bed when the compressor came on. It was not noise, but the jolt of the compressor transmitting through the bench seat/bed. Could have eliminated that if I could be bothered, but wasn't worth it.
The 240V Inventor Fridge was totally silent. The only way I knew it was running was to open the door and see if the light came on (the Fridge woke up the Inverter to run the compressor when needed, so when compressor off, light stayed off). I think everyone who has bought the Inventor Fridges for their campers have been happy with them.
My current 240V LEC Fridge/Freezer that replaced the Thetford 3-way is also totally silent and again I open the door if I want to check if it is running or not (as Fridge temp dictates if fridge gets power to run).

However .... I have a new Hoover Fridge-Freezer in the house and THAT, when running, makes some unusual sounds. It is in the kitchen so doesn't greatly matter, but I could imagine that unit might be annoying in a Motorhome?
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Yes our home fridge is quite noisy it seems to ramp up then shut off for ages, but the actual start is noisy too.
 
Are they as reliable as domestic fridges?

I've never had to replace one at home other than them starting to get noisier or rusting.
 
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