Compressor Versus Absorption Motorhome Fridge.

[Bevbun]

Looking for advice, have a domestic 3 way fridge which is totally unreliable so looking to swap for possibly a compressor 12/24 v fridge with freezer space . So, any reasons why I shouldn’t change it? If I do what do I need to be looking for? Any help appreciated

 

[LostinWales]

I’ll tell you next week it says 525mm and my door is 525mm
Interference fit

Just got mine out with 10mm to spare

 

[LostinWales]

When you change from a 3 way fridge to a compressor fridge what do you do about the vents in the van?

Leave them there. You could block them with a covering on the inside, or Dometic do winter covers which I might invest in.

 

[barryd]

I could never buy a fridge freezer for the van that relied on electricity alone. I spend a lot of time plugged in to 4kW of solar but even this would struggle through UK winter months and needs extra grid leccy.

You can nearly always find gas. You can't always find sunshine.

That's why the four way fridge I invented in my head earlier would be better.

 

[oldiesontour]

My 240 volt fridge and dedicated inverter takes around 3 amp (@12v) when running average about 1/3 to 1/2 the time so between 1 to max 2 ah @12v

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[oldiesontour]

Should also say we have a 12v compressor cool box running as a freezer that is more like 5ah

 

[olley]

olley oldiesontour
Whats the consumption of your mains units like and did you experience any issues with the installation / operation of your units please?
With sufficient energy available it strikes me that fitting a mains unit is a no brainer if they function ok in that environment....!

I fitted mine in the RV, it's made by Beko, this was the closest f/f I could find in size to the hole left by the old one.
The height was perfect at 1520mm, it was just the sides that needed filling, about 25mm each side.
I used 25x40mm softwood screwed into the housing and then a black sealant/glue to fill the small gap.
That was this week so not been tried in earnest yet.
I don't see any problems if you have enough solar and batteries, which the RV does have.
Our little Autocruise is a different matter, it came with a small compressor fridge, I have fitted 200watts of solar and 200ah of gel batteries, but a weekend without sun and they are well down.

 

[Richard n Ann]

I was thinking of the scenario of say if you were parked up in a field for a month in April or October. You might get a week of dull weather. Chances are you would be ok with a decent lithium and solar setup if you didnt have a constant draw on the batteries. This is where the ability to switch a compressor fridge back over to gas would be useful. Just thinking along our own lines of how we motorhome which is a bit different to others. Sometimes the above scenario is exactly what we do. Im in our van right now and we have been off grid in the same place for a month. Most people move on regularly so in that scenario it wouldnt be a problem but in ours it might be.

I made our panel tilt 2 ways (forwards or backwards) for October in Benidorm and the power went up to full power again, 9 amps. Can't remember the exact numbers but it makes a massive difference, something like 3 amps flat to 9 amps tilted

 

[Jabstatt]

They consume way LESS energy.

Look at the facts.

The efficiency is way better.

Half a kWh a day.

Tony

 

[Sheddy]

We recently were parked up in Berlin in very warm weather where that van was unoccupied for 4 days. The control panel and all other 12v loads were off apart from the supply to our compressor fridge freezer. The fridge was set at 3/5 and the freezer 2/3.
Below is the Yield chart from our 300w solar supplying 200ah lithium.

The unoccupied days were the 9th -12th. The corresponding ambient temperatures were 26, 27, 26, 28 ° C and partially cloudy. The van was parked without shade. The total yield for the 4 days was 4.75 kwh which would equate to roughly 80+ ah a day. If the fridge compressor runs at 4amps it suggests it was running 20hrs a day.
I visited the van every day and the internal temperature exceeded 40° C.
The 3 days 13th - 15th when we were back in the van the temperatures increased to above 30, but the interior of the van was cooler as we were running the Endless Breeze with all Heki's and windows open.
Last winter in Spain we successfully run the fridge from the solar on 280ah LA batteries without hookup. Its a lot cooler and the fridge was not working hard.

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[barryd]

I made our panel tilt 2 ways (forwards or backwards) for October in Benidorm and the power went up to full power again, 9 amps. Can't remember the exact numbers but it makes a massive difference, something like 3 amps flat to 9 amps tilted

Great idea. I believe you can get tiltting panels but they are expensive. I quite fancy something coming up out of the roof like out of "The man with the golden Gun"

 

[Mucklestone]

Something people don't talk about when getting a new compressor fridge is how the installation can effect the performance.

For example, for good performance a compressor fridge needs decent thick wire from the battery. Thin wire, which is typically used by manufacturers for three way fridges, will not run a compressor fridge well. Thin wire causes voltage drop, wasting a little bit of your energy heating up the thin wire. Just a small voltage drop really effects the performance of a compressor fridge. Upgrading to thick, decent quality wire really makes a difference with compressor fridges.

Second is ventilation. Whilst compressor fridges do not need wall vents like a three way fridge, you still want the back of them to be as cool as possible. The hotter the back of the compressor fridge is, the more power it uses to keep the inside cool. I can't find the link right now but there was a YouTube video testing the effect of ventilation. He put two big brand compressor fridges side by side but one was in a cabinet with a 4" x 4" rear vent hole and the other was just in the open. The fridge in the cabinet used almost twice the power to keep the inside cool. Whilst we will never be able to replicate sitting the fridge in the open, the more ventilation the better.

Finally solar panels really do support fridges well. On hot days when the fridge is running a lot, that is when you normally generate the most solar. On cold days, when you don't generate much solar, the fridge doesn't tend to need very much.

 

[wfdTamar]

When my 3way died I looked at the 3 options and installed a 240 volt Beko TSE 1284 running off a Victron Phoenix 800VA inverter. I kept the vent fans. That was the most efficient and quietest fridge I could find that fit. It works great. Much better than the 3way. So far been in as high as 39 C.

 

[Steve-N]

Thetford compressor fridge TC2090C with small freezer section. Came with van which is 15 months old.

The fridge is the main power consumer so the factory fitted 90Ah AGM only lasted 3 days at best off grid.

I have the same fridge/freezer, the van conversion company fitted a 90Ah AGM, which used to struggle if the van wasn't driven for a day to charge the battery.

I have now fitted 2x100Ah AGM's and 150w of solar with a MPPT controller, and can run easily for 4/5 days without EHU.
Compressor fridges are the dogs whatsits, I only need to have it at setting 2 even in 35° and have no issues.

 

[Helgamobil]

I'm looking to change from Absorption to compressor.

The only motives are off grid use and the ever rising cost of LPG.

It would be great, if you do change, to hear about the steps, trials and tribulations.

Are you planning on removing a window to get it in, for example?

Thanks

Tony

We struggled to get the old 3way absorption fridge (under counter size) out of the hab door and had to remove a metal “shield” on fridge to do it. I have heard of people removing passenger seat and going out through cab door.

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[Helgamobil]

When you change from a 3 way fridge to a compressor fridge what do you do about the vents in the van?

Leave them there. Covered the larger circular home with tape and put the vent cover back on. We have foam down either side of new compressor fridge to stop inward draughts.

 

[Helgamobil]

Something people don't talk about when getting a new compressor fridge is how the installation can effect the performance.

For example, for good performance a compressor fridge needs decent thick wire from the battery. Thin wire, which is typically used by manufacturers for three way fridges, will not run a compressor fridge well. Thin wire causes voltage drop, wasting a little bit of your energy heating up the thin wire. Just a small voltage drop really effects the performance of a compressor fridge. Upgrading to thick, decent quality wire really makes a difference with compressor fridges.

Second is ventilation. Whilst compressor fridges do not need wall vents like a three way fridge, you still want the back of them to be as cool as possible. The hotter the back of the compressor fridge is, the more power it uses to keep the inside cool. I can't find the link right now but there was a YouTube video testing the effect of ventilation. He put two big brand compressor fridges side by side but one was in a cabinet with a 4" x 4" rear vent hole and the other was just in the open. The fridge in the cabinet used almost twice the power to keep the inside cool. Whilst we will never be able to replicate sitting the fridge in the open, the more ventilation the better.

Finally solar panels really do support fridges well. On hot days when the fridge is running a lot, that is when you normally generate the most solar. On cold days, when you don't generate much solar, the fridge doesn't tend to need very much.

 

[Helgamobil]

We installed a compact “computer”fan behind the compressor fridge (and left the vents in situ) to keep it cool - we have seen installations with 3 of these compact fans used! Fridge is run off the lithium battery without issue, (lots of solar but can of course plug van into mains!)

 

[Pausim]

For example, for good performance a compressor fridge needs decent thick wire from the battery. Thin wire, which is typically used by manufacturers for three way fridges, will not run a compressor fridge well.

Not sure I understand that bit. The 12V operation of a 3 way fridge uses 3 times the Amps that my current 12V compressor fridge uses. Why would the compressor need a heavier gauge wire?

We find our compressor fridge far better than the 3 way one we had in our previous motorhome. It also uses less electricity than I expected and runs much quieter than some people suggest. We don’t even bother to use the night mode. Very much quieter than the 230V compressor fridges we have at home, clearly the 12V ones have been designed for quiet operation and to go easy on the batteries.

 

[ambo2camper]

Looking for advice, have a domestic 3 way fridge which is totally unreliable so looking to swap for possibly a compressor 12/24 v fridge with freezer space . So, any reasons why I shouldn’t change it? If I do what do I need to be looking for? Any help appreciated

I USED to persevere with 3 way fridges. I swore by them and have had them in 4 campers.
I've just removed my current 3 way fridge because it became troublesome. I did service it many times and finally admitted it was not efficient enough.
I'm now the proud owner of a 12v Vitrifrigo fridge. One switch ( ON/OFF). Hardly uses any power and I'm over the moon with it.

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[TCG]

Not sure I understand that bit. The 12V operation of a 3 way fridge uses 3 times the Amps that my current 12V compressor fridge uses. Why would the compressor need a heavier gauge wire?

We find our compressor fridge far better than the 3 way one we had in our previous motorhome. It also uses less electricity than I expected and runs much quieter than some people suggest. We don’t even bother to use the night mode. Very much quieter than the 230V compressor fridges we have at home, clearly the 12V ones have been designed for quiet operation and to go easy on the batteries.

As previously said we have recently had a new domectic 10 series compressor fitted by the dometic workshop. they replaced the existing wiring with 10mm going straight back to the battery... the fridge also came with a fan fitted to the rear pushing air across the fins

 

[Zebede4500]

Looking to replace an undercounted, over wheel arch, 3 way fridge with a compressor fridge but haven’t found anything to fit!!! Van is an Autosleeper Nuevo 2004.
Anyone found the answer ??

 

[1967bowesj]

As previously said we have recently had a new domectic 10 series compressor fitted by the dometic workshop. they replaced the existing wiring with 10mm going straight back to the battery... the fridge also came with a fan fitted to the rear pushing air across the fins

Think they went a bit over kill unless your original wiring was crap, 10mm so roughly 70amps, what is the fridge rated at?
Which Dometic Workshop fitted this and was it under warrenty or cost to you

 

[Pausim]

As previously said we have recently had a new domectic 10 series compressor fitted by the dometic workshop. they replaced the existing wiring with 10mm going straight back to the battery... the fridge also came with a fan fitted to the rear pushing air across the fins

I still can not see why something that draws less power needs a bigger wire than the original heavier demand. Suggests to me the original wiring was inadequate. My Thetford compressor fridge needs smaller wires as shown in the installation manual.

 

[helzie2020]

Compressor fridges are better, fact of life. However they do consume a lot more energy and will drain even the best batteries within 24 hours. Even the more modern tall slimline absorption fridges are power hungry... around 230 watts on 12v when driving.

We have a Dometic RC 10.4P.100 12v compressor fridge with small freezer. The manual gives the average power input as 48W and the energy consumption in 'Performance' mode as 0.48 kWh/24 h (so 40 Ah/24 h). So those figures suggest that the fridge should not drain our 200 Ah lithium battery in 24 hours.

If we are off grid for one night, our lithium battery drops from fully charged when we park up to about 70-85% the next morning (depending on various factors, including whether we are getting any solar energy on the roof panels). That seems to confirm what Dometic's consumption figures say.

I try to remember to switch the fridge to 'Quiet' mode overnight, which I think uses a bit less energy (the fan runs lower).

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[Jabstatt]

Looking to replace an undercounted, over wheel arch, 3 way fridge with a compressor fridge but haven’t found anything to fit!!! Van is an Autosleeper Nuevo 2004.
Anyone found the answer ??

Me too!

I have a Dometic RMSL8500 and likewise can't find a wheel arch compressor fridge.

Neither can I get hold of Thetford to ask! They refer to their dealers who cannot answer!

Any ideas?

Right now I may have to raise the floor to above wheel arch and rehouse the microwave which is above the fridge. Not a perfect solution. Turns a simple job into a project.

Tony

 

[ianp]

Think they went a bit over kill unless your original wiring was crap, 10mm so roughly 70amps, what is the fridge rated at?
Which Dometic Workshop fitted this and was it under warrenty or cost to you

I think the reasoning is that low voltage cable is in reality specified for the reduction of volt drop rather than for current capacity.......though regardless of the former it will always need to achieve the latter.......

 

[Jabstatt]

The installation instructions of a compressor fridge specify the cable sizes. Bear in mind that is the battery is five metres away, its a ten meter run plus and buggeration factor.

The three way fridge uses a heater, whether on gas, 12v or 240v The voltage drop doesn't make a lot of difference to a heater but a compressor fridge has a high inrush current on start up when a volt drop would delay the start and could damage the motor.

Look at the power consumption figures for comparison. Compressor is way more efficient at around half a kWh a day.

Tony

 

[Tude]

I’ve fitted a Thetford T2160. 2 yrs ago just a direct 12v feed with a fuse. It’s using about 35amps over 24hrs if I put the night mode on it’s about 26amps. Its quiet also you can set the freezer to -6/-12/-18 also you can turn the freezer off and just run the fridge then the amps are really low. You don’t need fans or the vents just board them up and seal them. Vans that come as standard don’t have vents at all!! The Thetford breaths through the front where it sucks fresh air in and blows warm air out !! It’s far better than 3 way and bigger inside and you can fill the top shelf where you can’t with absorption

 

[tonyidle]

We struggled to get the old 3way absorption fridge (under counter size) out of the hab door and had to remove a metal “shield” on fridge to do it. I have heard of people removing passenger seat and going out through cab door.

Almost all fridges have easily removable doors and may measure less front to back rather than side to side with the door removed.

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[ROADRUNNER700]

I fitted a compressor fridge to my van I only have a 100w solar panel and two 95 amp batteries it's one of the best items I've fitted. Admittedly I move every couple of days which recharges the batteries. But its a game changer. I only used a litre and a half of gas on a 4 week trip in France so it's a win win

hi bobby dazzler i to fitted compressor fridge 3 years ago its russell hobbs small 17ltr fridge 240v max power 40w with temperature thermostat off ebay cost new £50.00 free delivery + 3 years warranty its uk make its the best thing that i buy new works all summer long & winter wkends in camper i have just got another new reggio 25 ltr compressor fridge + freezer as well just fitted to van off ebay new £149.00 free delivery power with temperature thermostat ac 240v 1.0a-0.5a ac 26w-42w. dc 12v 1.6a -3.2a i have 2 x 95a van battery as they charge up faster than caravan battery in my 45 years experience and lot cheaper to buy from £ 100.0 upto £ 135.00 most with 4,5 years warranty & solar panels of 353 watts i run both russell hobbs & reggio fridge, freezer off 150w inverter its the best thing i have buy with the power used in the night the solar panels charge battery up next morning hope this is of interest to every one this set up works for me 1 russell hobbs small fridge & reggio 25 ltr fridge freezer both compressor +12v lights + 12v tv all most for got my camper van friend on motor home fun called dulux as negative thinking ? not thinking right ? i do hope is well & now thinking more positive hope is in the 2024 century now no a fence given as he not agree with using x2 new 95 amp van battery as leisure battery for lights ,tv ,fridge says advice not right he must have caravan shop ? selling caravan leisure battery ££££ carry on camping