Dometic 3 way fridge

[Dobbie]

Hey @Bellbirdweb .....I hope they've got heaps of money to justify it. It doesn't make sense (to me, at any rate,) to input power to a battery, converting it to 12v then convert it back to 240v with the resultant losses.

And we do loads of free camping as well....when the fridge just has to work efficiently...and never had an issue......at lasted for weeks at a time.

We survive very easily on 150 of solar, a185 fridge / freezer and a spare portable 120 solar panel which is rarely used.

I suspect some of the fridge issues are related to sticky young fingers constantly opening fridge doors....I've watched it often....but then I'm a GOF.!

 

[Bellbirdweb]

Hey @Bellbirdweb .....I hope they've got heaps of money to justify it. It doesn't make sense (to me, at any rate,) to input power to a battery, converting it to 12v then convert it back to 240v with the resultant losses.

And we do loads of free camping as well....when the fridge just has to work efficiently...and never had an issue......at lasted for weeks at a time.

We survive very easily on 150 of solar, a185 fridge / freezer and a spare portable 120 solar panel which is rarely used.

I suspect some of the fridge issues are related to sticky young fingers constantly opening fridge doors....I've watched it often....but then I'm a GOF.!

It would need to be 12v inverter fridge to make sense in a caravan.

Inverting from 12v to 240v to run a 240v inverter fridge, as efficient as they may be, still seems a long way around.

 

[mikerezny]

I definately have to disagree again....the three way is fine for 99pc of the time it's used and the other 1pc can be minimised by careful use....not removed, but minimised.

The alternative is hellishly expensive and heavy unless you go with lithium batteries...also still expensive .....

There seems to be a huge move to and discussion of alternative fridge power. Maybe I'm out of the loop and out of date ...or maybe I don't read the articles or follow the forums but....

I really can't see the point in looking at expensive alternatives when what is standard on the van is adequate.

As said, we've used the three way fridges for yonks and never had a problem ....we've also used Waecos and found their power demands ridiculous, particularly when free camping.

It seems that to get the little bit extra in fridge efficiency it's necessary to spend a huge amount....I'd rather spend my money on something else!

(We do use fridge fans, a fridge awning when required and have an Accurite fridge monitor...only recent issue is the need to mildly defrost the freezer in humid conditions but that was once only and it took 30 minutes)

I hate spending money where I'm not convinced it's necessary.

But again....to each his own.

Hi @Dobbie,
first off, I completely agree with you. I have also done as many tricks as I can to our Dometic RM2350. Most of the ideas weren't new they came from this and other forums.

We aren't planning to go on extended trips up in the hot tropics, so what we have is working fine and given that
1: I am as tight as ...
2: Any upgrade to avoid an absorption fridge will cost big $$ for a new fridge, cost more in solar and batteries, and be problematic if there isn't sun for a few days or more.
So, the Dometic absorption fridge is probably going to be in our van for some time yet.

But, my natural curiosity leads me to fossicking around, especially when I discover a 'new' technology such as inverter fridges and evaluating their potential use to me.

I also know that there are a lot of experienced people on this forum with a great range of views on all sorts of topics of interest to me. So I don't hesitate to solicit opinions. I like to know what alternatives are available even if I am not yet ready to change.

We used our fridge continuously for 16 days. The only ice in the freezer was a thin layer on the cooling plate at the back. But a lump of ice about the size of a thumb was in the top right-hand corner between the cabinet and the cooling fins. Seems like this appeared at Pink Lakes when we had three days around 30-32C and warmish nights. I think having plastic containers on all the shelves and a crisper tray vastly reduces the amount of moisture laden air each time the door is opened and hence the amount of ice build up around the cooling fins.

cheers
Mike

 

[mikerezny]

Fitting instructions are usually in the manual for the fridge but usually a couple of screws behind fascia.....................Don't think drilling thru the bench top would allow much access.

Fans are best positioned above the the condenser to draw the air, gives better air flow, you will find that following the gap allowance described in the fitting instructions combined with the fans the walls stay a lot cooler.

Hi @Drover,
on the camper trailers, there is no room above the condenser fins to fit any fans. The fridge just fits in under the bench top. The top of external vent is just below the benchtop. The best one can do, is to 1, mount fans on the top external vent, blowing out, 2, on the bottom external vent, blowing in, or 3, as is done by Dometic and Thetford mount them to the back of the fridge blowing up. There seem to be advantages and disadvantages to all three options.

Considering these three options for a camper trailer, I currently have one on the top vent. I hesitate to put one on the bottom vent because there is more dust and moisture. I like the idea of putting them under the condenser fins, but that will have to wait until I pull the fridge out in November. When I do that I might also look at using a linear cross flow fan.

cheers
Mike

 

[Drover]

Lets see........................

@Boots in Action . it's cool not ever having any money to pay people to do things has forced me to be a bit of a MacGyver and likewise can crap on a bit too much I'm afraid.........................but I do like seeing what others are doing and how they do it, love to problem solve as a kid I was the one to pull something apart to see why it worked....................and if it was Dads then extra incentive to put it back so it still worked.

Back on Topic...................(a weird feelling ).....................Once I've fitted the fridge up properly I've found the 3 way to work okay even living in our van for 6 mths wasn't enough to make me, throw it out and spend mucho big bucks on a compressor fridge, if it breaks then a decision would be made, nah I would repair it, be way cheaper..........add a fan inside to improve things but last trip I could chuck a few tinnies in it at morning smoko and all good by beer oçlock so nothing wrong with that.
I think from looking at a lot of rigs people load too much in the fridge for starters and when little fingers are stopped from opening the door every 5 mins all is good........................Like my small beer fridge at home if the door is opened too much and being small dumps it's cold on the floor and needs a lot more work to build up again, I suppose the best way would be to lay the thing on it's back and have the lid on top like my Engel which by the way being older than some of you on here actually turns 12v to 240v to run, not sure if they still do though........it turns 40 next year so may be retired as it can sure chew some juice when it wants to nowadays.

Fan location above or below the fins is academic I suppose, ease of access nails it for me but basically on top draws the hot air making sure it doesn't hang around, creating a low pressure causes air to move by itself thus , should increase the flow and lighten the load on the fan, fitting on the lower vent could cause the air flow to swirl and not draw direct, who knows, I even toyed with a bigger vent but then that would defeat the flow over the tubes.....................................it works, the beer is cold, so happy.

 

[Dobbie]

Yep @mikerezny ....totally agree that new technology is interesting and can be challenging....so it's always a good idea to keep up but it seems that some things are getting ahead of themselves a bit.

The tendency to throw the baby out with the bath water worries me a bit as the pricing on 'things we simply must have' only leads to some potential buyers being priced out of the market, and maybe some overextending themselves and not being able to then afford to use their vans as often as they'd like.

My fridge gripe I've mentioned before....it's an electronically controlled panel that requires constant 12v...I know it's 15ah just to run the panel but can't see the sense in it. It should be able to switch from AC to DC to gas without the electronic wizardry.....so I reckon it's over designed.

We had to look at extra battery power to cater for that ...not much but it was a consideration.

When I think back to our initial forays into long term off grid camping, I shudder. We were innocent! The fridge was a Chescold three way which had to be lifted in and out of the car to run on gas...we hated it by the time we were home...but it did allow us to be self sufficient for up to three weeks. The battery we had was deep cycle but we weren't aware we had to keep it charged regularly and so it died. One 12v socket for the portable shower pump, head lamps for reading and a rechargeable Coleman lantern.

That was mid 1990's and we thought it was the bee's knees! ( and had a chippie for the morning coffee stop)

By 1996 we'd added solar... 40w panel, no regulator, and an intense interest in the potential of solar...and that cost us about $800 then.

so I do accept progress...reluctantly sometimes....but, as said, worry about trends for the sake of trends, rather than necessity. For penance I will do some extra reading.

 

[Drover]

Missed your post above @mikerezny , was sitting too long writing and you posted, I thought you had vents top and bottom on the outside wall like a Swan and you could just Sikalex a fan or 2 onto the inside of the vent............

 

[Drover]

My new mantra @Dobbie "I'm not going off topic, I'm not going off topic............"

 

[mikerezny]

Missed your post above @mikerezny , was sitting too long writing and you posted, I thought you had vents top and bottom on the outside wall like a Swan and you could just Sikalex a fan or 2 onto the inside of the vent............

View attachment 48985

Hi @Drover,
Sorry, I didn't explain more clearly. Yes, the Penguin has an external outlet vent at the top, just below bench level and an external inlet vent at the bottom at floor level. They are both quite a bit smaller than the vent in your photo.

The earlier model Jayco camper trailers also had a vent inside on the bench top just above the condenser fins. But that is no longer done. I assume that is because of the new regulations regarding ensuring that no gas from the back of the fridge can vent to the interior. Pity, in some ways, since people defrosted things on top of this vent. And it warmed the interior of the van a little in Winter.

I have used cable ties to put a 120mm fan on the inside of the top vent. 120mm is the biggest fan that will fit on the vent.

Here are three pics showing the fan, wiring and thermostat, and insulation around the top of the boiler to keep the heat away from the cabinet. Note that the insulation is only a temporary solution to see if it was effective. It is, so it will get done properly when the fridge comes out. It has already been there for over 5,000 kms so it will last another 5,000 kms.

cheers
Mike

 

[mikerezny]

Yep @mikerezny ....totally agree that new technology is interesting and can be challenging....so it's always a good idea to keep up but it seems that some things are getting ahead of themselves a bit.

The tendency to throw the baby out with the bath water worries me a bit as the pricing on 'things we simply must have' only leads to some potential buyers being priced out of the market, and maybe some overextending themselves and not being able to then afford to use their vans as often as they'd like.

My fridge gripe I've mentioned before....it's an electronically controlled panel that requires constant 12v...I know it's 15ah just to run the panel but can't see the sense in it. It should be able to switch from AC to DC to gas without the electronic wizardry.....so I reckon it's over designed.

We had to look at extra battery power to cater for that ...not much but it was a consideration.

When I think back to our initial forays into long term off grid camping, I shudder. We were innocent! The fridge was a Chescold three way which had to be lifted in and out of the car to run on gas...we hated it by the time we were home...but it did allow us to be self sufficient for up to three weeks. The battery we had was deep cycle but we weren't aware we had to keep it charged regularly and so it died. One 12v socket for the portable shower pump, head lamps for reading and a rechargeable Coleman lantern.

That was mid 1990's and we thought it was the bee's knees! ( and had a chippie for the morning coffee stop)

By 1996 we'd added solar... 40w panel, no regulator, and an intense interest in the potential of solar...and that cost us about $800 then.

so I do accept progress...reluctantly sometimes....but, as said, worry about trends for the sake of trends, rather than necessity. For penance I will do some extra reading.

Hi @Dobbie,
yes, I read an earlier post from you about the excessive current draw of the fridges with auto changeover and will keep that in mind. The manual Dometic suits me just fine. I can handle turning the knob to select between gas, 240V or 12V. Your panel draws more power than what it takes to run my fridge fan continuously.

Gee, in 2016, I thought I was moving with the times buying a 40W solar panel for $30 ($50 before an eBay offer) and about $20 on my solar regulator set up. I need only an hour or so each day to keep the battery fully charged. I usually leave it on for a couple of hours to float the battery for a while.

Here are some photos:
(I am not off topic either. Just explaining how I get enough power to run the fans that make the Dometic 3-way fridge run more efficiently)

cheers
Mike

 

[Dobbie]

My new mantra @Dobbie "I'm not going off topic, I'm not going off topic............"

Aaaagggghhhh @Drover I stand corrected.....again.

but....it is Anzac Day and I was feeling a bit philosophical.




:focus:


:flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig::flypig:

 

[chartrock]

My new mantra @Dobbie "I'm not going off topic, I'm not going off topic............"

ound:ound:ound:ound:ound:ound:ound:ound:ound:ound:

 

[Drover]

ound:ound:ound:ound:ound:ound:ound:ound:ound:ound:

...............................:focus:...............................................................................

 

[Moto Mech]

Having just completed 12 mths touring Aus, the most problems we came across were peoples 3 way fridges failing in the heat. I reacon we heard it over 100 times(and we stayed at very few parks), our own new ST rated 3way was useless but after going to a Evakool compressor fridge, never ever had any more dramas.
Our current van has a 3 way, works great here(in Tassie) but id never trust it to touring the big island with.

 

[Drover]

Come across it a lot myself, usually find the fitting is rubbish and causing the problem but they could be more efficient.

 

[Boots in Action]

Hi @Dobbie,
yes, I read an earlier post from you about the excessive current draw of the fridges with auto changeover and will keep that in mind. The manual Dometic suits me just fine. I can handle turning the knob to select between gas, 240V or 12V. Your panel draws more power than what it takes to run my fridge fan continuously.

Gee, in 2016, I thought I was moving with the times buying a 40W solar panel for $30 ($50 before an eBay offer) and about $20 on my solar regulator set up. I need only an hour or so each day to keep the battery fully charged. I usually leave it on for a couple of hours to float the battery for a while.

Here are some photos:
(I am not off topic either. Just explaining how I get enough power to run the fans that make the Dometic 3-way fridge run more efficiently)

cheers
Mike
View attachment 48998 View attachment 48999

Hi Mike, was trolling through some recent threads and noticed yours showing setup of fans at rear. Also noticed you have a thermostat control on top tube at back. Can you let me know the ranges of its operation and where I could possibly get one. It may or may not be suitable up here in sunny/hot at times Queensland, but at least then i will not be having to turn the fans on/off manually. Picture of loop in drain tube tomorrow hopefully as friend is away today. Cheers

 

[Boots in Action]

Lets see........................

@Boots in Action . it's cool not ever having any money to pay people to do things has forced me to be a bit of a MacGyver and likewise can crap on a bit too much I'm afraid.........................but I do like seeing what others are doing and how they do it, love to problem solve as a kid I was the one to pull something apart to see why it worked....................and if it was Dads then extra incentive to put it back so it still worked.

Back on Topic...................(a weird feelling ).....................Once I've fitted the fridge up properly I've found the 3 way to work okay even living in our van for 6 mths wasn't enough to make me, throw it out and spend mucho big bucks on a compressor fridge, if it breaks then a decision would be made, nah I would repair it, be way cheaper..........add a fan inside to improve things but last trip I could chuck a few tinnies in it at morning smoko and all good by beer oçlock so nothing wrong with that.
I think from looking at a lot of rigs people load too much in the fridge for starters and when little fingers are stopped from opening the door every 5 mins all is good........................Like my small beer fridge at home if the door is opened too much and being small dumps it's cold on the floor and needs a lot more work to build up again, I suppose the best way would be to lay the thing on it's back and have the lid on top like my Engel which by the way being older than some of you on here actually turns 12v to 240v to run, not sure if they still do though........it turns 40 next year so may be retired as it can sure chew some juice when it wants to nowadays.

Fan location above or below the fins is academic I suppose, ease of access nails it for me but basically on top draws the hot air making sure it doesn't hang around, creating a low pressure causes air to move by itself thus , should increase the flow and lighten the load on the fan, fitting on the lower vent could cause the air flow to swirl and not draw direct, who knows, I even toyed with a bigger vent but then that would defeat the flow over the tubes.....................................it works, the beer is cold, so happy.

Hi Drover, about fan placement you are correct about placement of a single/multiple fans in the TOP vent. The closeness of the fans creates a better local draw of the air through the cooling fins which are just below. If a single or multiple fans are fitted to the BOTTOM vent, you are relying on air from anywhere in the area of the fridge being forced out of the vent above and not necessarily through the cooling coils. I think if only fitting one lot of fans, it should be in the top. Top and bottom is as good as you can get.

 

[Bellbirdweb]

Hi Drover, about fan placement you are correct about placement of a single/multiple fans in the TOP vent. The closeness of the fans creates a better local draw of the air through the cooling fins which are just below. If a single or multiple fans are fitted to the BOTTOM vent, you are relying on air from anywhere in the area of the fridge being forced out of the vent above and not necessarily through the cooling coils. I think if only fitting one lot of fans, it should be in the top. Top and bottom is as good as you can get.

I have one of the rooftop top vents on mine, so based on this theory, I should be fitting the fans at the top to create a negative pressure.

Has anyone fitted one to a rooftop top vent ?

 

[Boots in Action]

I have one of the rooftop top vents on mine, so based on this theory, I should be fitting the fans at the top to create a negative pressure.

Has anyone fitted one to a rooftop top vent ?

Hi Bellbird, you re fast on the keyboard!! I think that fitting an extraction fan on the rooftop might not be as good as it is for us with smaller fridges where the cooling fins are very close. The further away from the cooling fins, the less the value, unless you are creating a lot of air movement from below. Not fully up with rooftop vents etc. Perhaps Drover or Dobbie can help you with this.

 

[mikerezny]

Hi Mike, was trolling through some recent threads and noticed yours showing setup of fans at rear. Also noticed you have a thermostat control on top tube at back. Can you let me know the ranges of its operation and where I could possibly get one. It may or may not be suitable up here in sunny/hot at times Queensland, but at least then i will not be having to turn the fans on/off manually. Picture of loop in drain tube tomorrow hopefully as friend is away today. Cheers

Hi @Boots in Action,
I got them from Hongkong on eBay from the seller speed_mart.
It takes 2-4 weeks to arrive.

They arrived promptly and I would not hesitate to buy from them again.
I bought one each of 50C, 55C, and 60C Normally Open and they cost $1.31 each including postage.
I used the 55C one. I want the fans on whenever the evaporation fins are hotter than the ambient air, indicating he boiler is heating. I assume that if the outside temperature gets up to 55C, I won't care much about the fan being on or not.

They have them in a wide range of temperature values in both normally open and normally closed.

This is the description:
Temperature Switch Control Sensor Thermal Thermostat 55°C N.O. KSD301

The link to the 55C one is:
http://www.ebay.com.au/itm/Temperat...D301-/262383064210?hash=item3d173fd492&_uhb=1

Like most Chinese eBay suppliers, you have to pay using PayPal.

Let me know if you need any further information.
cheers
Mike