compressor fridge against 3 ways

madcart · Senior Member

compressor fridge against 3 ways

markf · Senior Member

In my view and experience a good quality 240V/12V compressor fridge is the way to go. They're quite efficient and the better the quality (and bigger the price tag) the better they are insulated and therefore, over time, less power draw. We run two Engel 40 litre fridges, one as a freezer and the other as a fridge and with about 200Ah of battery available we have never run out of power with about 35W solar panels. We can last around 2.5 days without any input to the batteries. After that if there's still no sun we may need to idle the car for an hour or so. On a normal winter sunny day the batteries are at float by about lunch time.

Just make sure that your fridge compartment is well ventilated and out of the sun.

T1 Terry · Guru

We have fitted a lot of 240vac household inverter fridges to replace both 12v compressor fridges and 3 way fridges. We have never heard anyone complain about the fridge using too much power or not exceeding their expectations, or ever giving an ounce of trouble for that matter.
To run any compressor fridge you need 100Ah available min to cover a poor solar day. That means 200Ah of lead acid in what ever format you choose, or 100Ah of quality lithium battery. You will need 400W of solar for the fridge, not just to run the fridge but to recharge the battery while running the fridge and to recover from a poor solar day.
We recommend to have enough battery to last 2 1/2 days with no sun, so 2 full days and night and the 3rd night with still enough to make the call on the 3rd day as to whether the sun was going to come out, if you were going to move on to a better spot, whether to run the tow vehicle engine and let the DC to DC charger put some back into the battery or lug out a generator if you are carting one of those and use that the recharge the battery.
So, 400Ah of lead acid or 200Ah of quality lithium battery. 400w of solar in good solar weather will put out 116Ah, in the stinking hot weather the household fridge of around 250ltrs total fridge and freezer capacity will use 80Ah per 24hrs or less, so you would have 36Ah left to top up the battery.
No need to run a separate solar and battery system for the fridge, but not a bad idea to run a dedicated inverter just for the fridge, plus a USB charger so you can charge the phone or other devices any time you want to without needing to turn on another inverter. The Victron 275VA is probably the best inverter for this job and handles the loads an inverter type household fridge around the 250ltr mark with ease. That way, if anything happened to this dedicated inverter, you could run one of the other inverters with an extension cord until you could get the problem sorted.

As far as the solar, you know the old story, never have too much solar, so the 400w is a minimum, add more to cover any other power needs you might be drawing both during the day and to replace what you use from the battery over night.

Important things to remember when installing the fridge, you need enough clearance up each side to be able to slide your hand in, this is for airflow as the heat transfer is through the walls, don't add insolation anywhere around the fridge, they were designed to pass an Australian standards test of 48*S heat soaked in a 48*C ambient temperature room with no outside device to promote air movement. The insulation was good enough for the fridge and freezer to drop the freezer to -15*C and the fridge to 5*C in under 15 hrs from a full heat soaked load of 48*C, you don't need any more insulation if it can pass that test.
Next, make sure you have clear airflow away from the top of the fridge, don't box it in above the fridge so hot air gets trapped there.
You can seal off the vents in the wall to stop the dust coming in, the fridge doesn't need the extra air flow but the removable vents makes access behind the fridge easier than pulling it out for what ever reason.

T1 Terry

T1 Terry

madcart · Senior Member

Thanks for the info guys. Now to decide which one to get dometic or bushland 12v???

Cupie · Guru

I thought that TI Terry's response was excellent - taking his figures on face value. He has provided good advice on this topic many times in the past too.

But, Christine, you may have missed his advice that he installs 240v domestic fridges with an inverter & not 12v fridges.

I think that my old 3 way will see me out though. If not, I'd probably go down TI Terry's recommended path.

Bobdown · Guru

Hi Madcart,
We have a Dometic/Waeco 190 lt 240v/12v compressor fridge, which is not a household fridge as it has a built in inverter and basically runs on 12 v all the time, much like your car fridges.
It uses 5 amp per hour from memory, so 120 amps per day, though most of the night the light is on, so it has reached its min temp and is not running.
We have 300 w of solar and always have 13 v at sundown with the fridge going and down to 12.7 in the morning, have stayed off grid for weeks at a time.

www.dometic.com/en-au/au/products/food-and-beverage/refrigerators/rv-refrigerators/dometic-coolmatic-rpd-190-_-55487

Funny enough, when we had the van built, I opted for a 3 way, only to be told that was another $700 more, even though the compressor fridge is dearer, there was no gas line to the fridge location.

Wouldn't go back now.
Cheers Bob

T1 Terry · Guru

The 12v Bushman 190ltr compressor fridge comes in at around the $1900 mark, the Dometic RPD 190ltr is around the $2150 mark, the household 250ltr fridge freezer will cost between $450 and $700 depending on brand and model etc and if someone has a run out model on special they get even cheaper. I think we paid $100 for the first Fisher & Paykel 250ltr and $200 for the 249 model about 7 yrs later. The 249 had auto defrost and few other bells and whistles we thought would increase the amount of power it used, but it was actually about half the 250's power use. Compared to the latest inverter fridges it would be a power guzzler. When they changed to the new star rating because the old one didn't go past 5 stars, the newer inverter fridges get 2.5 stars, the Fisher & Paykel 249 gets about 1/2 a star, but it was 3.5 stars on the old star scale.
We have an LG Electrocool 253ltr two door fridge freezer in the Hino, it has dents all around it because the original owner didn't bolt it down, but it still runs 24/7 for the last 6 yrs that I know of and still going strong. The shelves are crap, the bouncing around broke the plastic shelves so I'd recommend something with the wire rack type shelves so the stuff in the fridge bouncing around doesn't break the shelves. I just glued a piece of 1.5mm aluminium sheet left over from reskinning the big bus project and they have held together since .... but it does look a bit agricultural

T1 Terry

madcart · Senior Member

biggrin Thank you all very much for all the information.We are now looking at an 240v inverter fridge Samsung or L.G any opinions on them???

Muskat55 · Veteran Member

We have an LG inverter fridge it uses 290 kWh per year. Got it on special from Good Guys $495 https://www.lg.com/au/fridges/lg-GT-279WDC

Jaahn · Guru

Hi smile

We have a small upright fridge, 12V/240 that I bought for more than a 240V fridge. We got sick of the chest units. I would now buy a small 240V fridge I think. I have a suitable inverter.

To stop the stuff on the shelves and the door pockets going everwhere when travelling and then falling out on your feet when you open the door, we now have a sheet of coreflute that we put in standing against the shelves when we travel. The door just keeps it in place and it is very effective doing the job. biggrin When we stop we just put it on top of the fridge.

Coreflute is the corrugated plastic sheet that the realestate agents use for signs. I cut away the corners and made it not too snug fitting so the air can circulate a bit. aww

Jaahn

bgt · Guru

FWIW we had a bus conversion. Installed a 180ltr household/domestic fridge. Replaced the 240v compressor with a 12v Danfoss compressor. Worked like a dream. Caveat - we had 1800ah of batteries and 6*Unisolar panels. But the key was to make sure the fridge is well ventilated. Plenty of air around it plus's a good vent above it to let the heat out. And shield the side from the sun if possible.

T1 Terry · Guru

madcart wrote:
Thank you all very much for all the information.We are now looking at an 240v inverter fridge Samsung or L.G any opinions on them???

Hisense, Fisher & Paykel, the list goes on. If it passed the Australian standards test so it could be tested for a star rating, then they are good quality. The interior strength of the shelves and the inside of the door is the thing to look for, as well as a unit that will fit in the spot you have is important wink

T1 Terry

T1 Terry · Guru

bgt wrote:
FWIW we had a bus conversion. Installed a 180ltr household/domestic fridge. Replaced the 240v compressor with a 12v Danfoss compressor. Worked like a dream. Caveat - we had 1800ah of batteries and 6*Unisolar panels. But the key was to make sure the fridge is well ventilated. Plenty of air around it plus's a good vent above it to let the heat out. And shield the side from the sun if possible.

This was the way to go 15 yrs or more ago, but now the 240vac inverter compressors are far better than any that run a 12v or 24v compressor. Shorter run times, faster temp pull down and use less battery power.

T1 Terry

T1 Terry · Guru

Jaahn wrote:
Hi
We have a small upright fridge, 12V/240 that I bought for more than a 240V fridge. We got sick of the chest units. I would now buy a small 240V fridge I think. I have a suitable inverter.
To stop the stuff on the shelves and the door pockets going everwhere when travelling and then falling out on your feet when you open the door, we now have a sheet of coreflute that we put in standing against the shelves when we travel. The door just keeps it in place and it is very effective doing the job. When we stop we just put it on top of the fridge.
Coreflute is the corrugated plastic sheet that the realestate agents use for signs. I cut away the corners and made it not too snug fitting so the air can circulate a bit.
Jaahn

I like the Lexon Thermoclear pieces idea, heavy duty coreflute really, it would help to stop the cold air drain a bit as well I guess.

We have those spring loaded bars with the rubber feet on each end. They screw out to adjust the uncompressed length, then they are just pushed into place to keep the stuff on the shelves. We use a length of wide Velcro to hold the door shut when travelling, a small piece glued to the front of the door and the side panel so the longer piece can be removed and hung beside the fridge when we park up. It is now part of the pre departure check list, but the stairwell in the Hino and in the Mazda do a great job of collecting all the stuff that escapes at the first round about if the Velcro retainer is not put back in place :lol:

T1 Terry

Bass · Senior Member

Bobdown, lucky you we have the same fridge and it is crap. Drains batteries almost overnite and would not shut down / idle . Had insulation batts on top removed, helped a bit, had no bottom vent, placed vent in helped a bit, covered both top and bottom internal vents, helped bit more, another solar panel on roof 480w in all. At easter our son removed 240v accidentally van in full sun 30deg days he realized his mistake 2 days later fridge off battery management system shut down. opened freezer door already starting to melt. freezer ok but fridge will not go below 8deg Our last van had 3 way and ran faultlessly in same areas this thing if we did not have the gennie could not have gone to cape york etc. Been dealt bit of a body blow my cancer has returned and have 2 to 3 years so after first lot of chemo 3 way fridge is going in and we off to pilbara area etc.

Cheers warren

Bobdown · Guru

Bass wrote:
Bobdown, lucky you we have the same fridge and it is crap. Drains batteries almost overnite and would not shut down / idle . Had insulation batts on top removed, helped a bit, had no bottom vent, placed vent in helped a bit, covered both top and bottom internal vents, helped bit more, another solar panel on roof 480w in all. At easter our son removed 240v accidentally van in full sun 30deg days he realized his mistake 2 days later fridge off battery management system shut down. opened freezer door already starting to melt. freezer ok but fridge will not go below 8deg Our last van had 3 way and ran faultlessly in same areas this thing if we did not have the gennie could not have gone to cape york etc. Been dealt bit of a body blow my cancer has returned and have 2 to 3 years so after first lot of chemo 3 way fridge is going in and we off to pilbara area etc.

Cheers warren

Very sorry to hear that Warren, all the best with that, hope you get some relief..............we have been there and done that in our family as well.

Honestly, the fridge worked a treat in the Kimberleys and everywhere else, fridge 2-3 degrees and freezer -18 degrees. I would have taken yours back, sounds like a condensor not cooling the gas or a refrigerent blockage or leak.

We have wool insulation on the sides and nothing on top or bottom of the fridge as per instructions, the outside caravan vents are just above the fridge top and bottom.

The orange light, would come on regularly during the night as the thermostat would switch off, we usually run on the 3rd blue light...........can see from the bed when nature calls.

Cheers Bob

PetenSue · Veteran Member

I cannot think of a reason to have a 3way fridge. We have a vitrifridgeo? Spelling, in our caravan and it works perfectly. Last year I bought 2 remote fridge monitors and after a few days we thought our fridge was no good. Reading 8 degrees in the fridge and minus 7 in the freezer. I put some stubbies in the fridge and they seemed fine We were going away last Christmas so we tried to get our fridge serviced but because of the time of year everyone was booked out. I even rang Kedron to get a new fridge installed but they were booked out too. My wife bought 2 $10 fridge thermometers from a kitchen shop and we put them in the fridge. 3 degrees and minus 16. Soooo. The 2 crappy fridge monitors are in the bin and no more worries. We had a kerosene fridge when I was a kid. I consider 3 way fridges as being the same as a kero fridge. Regards Pete

T1 Terry · Guru

PetenSue wrote:
I cannot think of a reason to have a 3way fridge. We have a vitrifridgeo? Spelling, in our caravan and it works perfectly. Last year I bought 2 remote fridge monitors and after a few days we thought our fridge was no good. Reading 8 degrees in the fridge and minus 7 in the freezer. I put some stubbies in the fridge and they seemed fine We were going away last Christmas so we tried to get our fridge serviced but because of the time of year everyone was booked out. I even rang Kedron to get a new fridge installed but they were booked out too. My wife bought 2 $10 fridge thermometers from a kitchen shop and we put them in the fridge. 3 degrees and minus 16. Soooo. The 2 crappy fridge monitors are in the bin and no more worries. We had a kerosene fridge when I was a kid. I consider 3 way fridges as being the same as a kero fridge. Regards Pete

Need to put the sensors for the fridge thermometers in either a plastic bag between 2 slices of bread (tend to go mouldy after a few mths if supermarket bread, a few days if bakery or home made bread), or in a pill bottle of water sealed up so the water didn't leak out. Placed towards the back of the middle shelf of the fridge, not the top shelf as that is the warmest part of the fridge, and taped to the top of the freezer compartment towards the back, to monitor the warmest part of the freezer.

T1 Terry

Tony LEE · Guru

Nothing wrong with 3 way fridges and in fact there are many advantages. Disadvantages too. I have 3 way, 12V compressor and domestic 240v. As far as I'm concerned, if the milk doesn't pour out of the bottle with lumps in it, the vegetables are reasonably un-limp, and the meat doesn't have a green slimy surface, then the fridge is working. Best way to drive yourself crazy with both solar power and refrigerators is to try to monitor the performance by adding instrumentation.

T1 Terry · Guru

Tony LEE wrote:
Nothing wrong with 3 way fridges and in fact there are many advantages. Disadvantages too. I have 3 way, 12V compressor and domestic 240v. As far as I'm concerned, if the milk doesn't pour out of the bottle with lumps in it, the vegetables are reasonably un-limp, and the meat doesn't have a green slimy surface, then the fridge is working. Best way to drive yourself crazy with both solar power and refrigerators is to try to monitor the performance by adding instrumentation

I guess we all have different efficiency measurements, cold beer and ice for Margaret and myself on occasions to have with a honey whiskey are the real points of measure for us. Ice cubes in under 30 mins and cold beer in the same time frame with a fridge that doesn't need a "do not open in hot weather" unofficial sign on the door is everything, the fact it is powered 24/7 for no additional cost and is less than a 3rd the cost of something that won't do as well are a bonus. I'd probably pay a power premium and purchase price premium for something that did the job as well as our household inverter fridges, the fact we get both of these at a reduced level was really a secondary thing we discovered after we installed our first solar/battery system to power our non inverter household fridges at the house back in Lake Illawarra well over 15yrs ago.

T1 Terry

EDIT: Sometimes computers seem to have a mind of their own, fixed it now

-- Edited by T1 Terry on Sunday 17th of November 2019 12:32:29 PM

Radar · Guru

Tony LEE wrote:
Nothing wrong with 3 way fridges and in fact there are many advantages. Disadvantages too. I have 3 way, 12V compressor and domestic 240v. As far as I'm concerned, if the milk doesn't pour out of the bottle with lumps in it, the vegetables are reasonably un-limp, and the meat doesn't have a green slimy surface, then the fridge is working. Best way to drive yourself crazy with both solar power and refrigerators is to try to monitor the performance by adding instrumentation.

Good on you, I like my 3 way frig and I would never try to justify.

blaze · Guru

I threw out a 3 way fridge when we were in broome after battling with it for 12 months. Very disappoint, could not get warrently, bugger me it was only about 30 years old. biggrin I thought it would have done better. We just put a bar fridge in run off 240v

Aus-Kiwi · Guru

Keep in mind in winter . The fridge doesnt need to be on
Or to be as cold as in summer . I have 12v 220l fridge freezer with 400 watt solar . It worked fine with 280 watt . If using an inverter on 240v the extra usage wouldnt be much . An extra solar panel
For safety .

T1 Terry · Guru

Aus-Kiwi wrote:
Keep in mind in winter . The fridge doesnt need to be on
Or to be as cold as in summer . I have 12v 220l fridge freezer with 400 watt solar . It worked fine with 280 watt . If using an inverter on 240v the extra usage wouldnt be much . An extra solar panel
For safety .

Actually the new inverter fridges, size for size, including the inverter losses use less power than the 12v/24v models. The issue might be getting inverter bar size fridges, they seem to start at around 250ltr and go up from there, but there could be some very efficient smaller capacity household inverter fridges out there or could be by next yr.

T1 Terry

Muskat55 · Veteran Member

Just for information. I have just run an LG279wdc 240v inverter fridge off batteries using a Victron 12/375 inverter. According to the power meter it has used 1.12 kWh in 48 hours. My maths says correct me if wrong, 1120÷12=93.3Ah divide this by 48h = 1.94Ah used per hour average. Even if very pessimistic with regard to inverter losses say 20% 1.94 × 1.2 = 2.33Ah. It is still an impressive figure, considering approx 70 l of freezer space and 200l + of refrigeration, with auto defrost and door cooling. The fridge draws approx 50w going flat out, defrost draws approx 150w for about 10 minutes per day. I used to run an Evkool 110l 12 v fridge and a 55l Fridgemate car fridge on freeze. Absolutely no comparison in performance. The best part is the LG was on special at the Good Guys for $495.

Greg 1 · Guru

I have a Thetford 180litre 3 way fridge freezer and am very happy with it. Have had it in some absolute stinking hot weather and it performed very well. No complaints at all.