danfoss vs absorption. cooling power?

NW Lady · 12-18-2021, 06:47 PM

I am wondering if a danfoss refrig would be better at keeping a good temp in refrig on warmish to hot days than an absorption. Size, insulation being the same.
Last summer had trouble with my dometic refrig in warm weather... 80 - 90 degrees.

Wondering if a defoss has more "cooling power".

Appreciate thoughts on this. thank you

Rlum · 12-18-2021, 07:08 PM

Quote:

Originally Posted by NW Lady

I am wondering if a danfoss refrig would be better at keeping a good temp in refrig on warmish to hot days than an absorption. Size, insulation being the same.
Last summer had trouble with my dometic refrig in warm weather... 80 - 90 degrees.

Wondering if a defoss has more "cooling power".

Appreciate thoughts on this. thank you

Definitely, cooling power is improved with compressor refrigerator. I am in process of converting my 3 way Dometic to compressor. Ordered the Vitrifrigo components and waiting for the compressor.

Only issue you will have to have enough battery bank and/or solar to run in hotter weather. When I had the Dometic 3 way, it would work adequately up ambient temps of 90. Beyond 90, refrigerator was struggling to keep food cold.

mkguitar · 12-18-2021, 07:22 PM

I know that my old 3 way will cool 60º~65º below ambient on propane

in a Phoenix summer that ain't so great. where we typically camp in the summer that is plenty

we try to go somewhere nice, park in the shade and I have fan kits

on shore power the cooling is not as good, but will work in a temperate area

on DC while driving it's a struggle- we rotate blue freezer packs between the freezer and the fridge to keep our food cold

my electrical system would require a major redo to support a compressor fridge.
mike

booster · 12-19-2021, 02:01 AM

No question that a Danfoss powered compressor frig will cool better and faster in nearly all conditions and especially at elevated temps.

We had an absorption and replaced it with a compressor frig over a decade ago and would never go with anything else.

You do need to be able to provide the necessary power to run, however, so make sure would have it. The biggest problem people have with compressor frigs is poorly done ventilation which will take away a lot of their performance.

GeorgeRa · 12-19-2021, 03:59 AM

Major advantage of compressor fridge is elimination of levelling requirement. Absorption fridges need to be leveled fore and aft about +/- 3 degree, none levelling failure is accumulative to a complete death. Only sometimes this failure could be reversed but fridge needs to be removed and flipped upside down a few times. Compressor fridges are immune.

Davydd · 12-19-2021, 01:15 PM

Elimination of the top and bottom outside vents through the outside wall is the most welcome piece going from an absorption fridge van to a compressor fridge van. I thought they were a cold leak in winter camping and a easy mouse entrance. My current design van couldn't accommodate an absorption fridge as the back of the cabinet is exposed in the open sliding door. I've found compressor fridges to work better at keeping temperature and were less fuss. Of course they are electric only and a 100ah battery as I had in my first van wouldn't cut it for a compression fridge.

TomF · 12-19-2021, 05:35 PM

I went with the compressor fridge after my first two absorption units died. Unfortunately, I chose a Norcold unit. The first time I plugged it into 110v AC, the voltage on the 12v side climbed rapidly. It got to almost 100v before I unplugged it. The dealer returned it, and i used the new unit for two seasons before the mother board fried. The dealer explained that the mother board was discontinued, and not available (on a 2 year old unit!). The electronics shops I went to said the board was not repairable.
So, I'm back to a Dometic absorption unit, which has worked out fine. In the end, I would say I liked having a compressor unit, but I didn't have the battery capacity to support it. If you go that route, stay away from NotCold (I mean Norcold).

RossWilliams · 12-19-2021, 06:51 PM

We have 250 watts of solar that basically provides enough battery charge to keep our compressor refrigerator running indefinitely. I haven't tested it with a combination of hot weather and short days. But then there aren't many places with that combination.

booster · 12-19-2021, 07:10 PM

Quote:

Originally Posted by RossWilliams

We have 250 watts of solar that basically provides enough battery charge to keep our compressor refrigerator running indefinitely. I haven't tested it with a combination of hot weather and short days. But then there aren't many places with that combination.

We have had the compressor frig and 200 or 300 watts of solar for a long time and also haven't had an issue in those conditions. Our worst recovery vs loss happened at Devils tower when we were there for 5 days. All were very heavy overcast and the sites also had moderate shade. It was also in the 80s for most of the time. We didn't really see much more the 10ah per day tops the whole time. At the time we had 260ah of battery and 200 watts of solar and didn't drive at all in that time so we got pretty low on SOC.

rvsprinterguy · 12-19-2021, 07:31 PM

We have the original Norcold absorption refrigerator in our 2004 Free Spirit, and it still works within its specs. The most common problem we have with it is freezing produce.

So, I picked up an Iceco chest-type compressor refrigerator/freezer. It has a danfoss-clone compressor and features the precise temperature control we were looking for. It's in the way, sitting behind the front passenger seat, but there's no better place for it. To power it in the van, I installed a fused cigarette lighter socket in the seat pedestal, which is wired to the house battery within.

We still use the Norcold when we travel, but temp-critical stuff goes in the Iceco.

When we're at home, the refrigerator goes in the garage where it's a test load for my solar panel/battery experiments.

When it's time for a new rig, we'll definitely be going with a built-in compressor refrigerator.

NW Lady · 12-19-2021, 08:24 PM

I have 400 ah lithium but no solar. I do have the old onan 2800 gen. and a 20 amp dc to dc charger. With a combo of my 45 dc panel and a separate 40 lithium plug in charger, I can get 80 amp going into batteries at same time with the generator. (There are two separate banks of batteries... 200 ah each). So I think I am ok for electricity. Looks like I need to find out more about the ventilation needs.
Thank you one and all for the info

themexicandoctor · 12-21-2021, 07:04 PM

3 Ways work fine for about 5-8% of users & these users are able to park level.

In the cooler months.

But come Summer, they Limp along & if like me, you are visiting patients in the hills of Los Angeles & unable to get perfectly level, eventually they fail & you are playing Russian Roulette with your food.

3 Way Fridges only work on LEVEL Surfaces and this was shared with me by a departing employee of 20 years, at Dometic, only after I raised Hell & went to the the top of the hierarchy over the course of 6 months - at the time it would have been the 4th replacement Dometic RM2354 since 2005 in a 05 Roadtrek 190 Versatile.

IF (and you do), have the battery bank, as I mentioned in another thread, buy a Novakool*, Isotherm or Vitrifrigo, not a TruckFridge**.

*my final choice after receiving a lot of advice from everyone here & marine & rv experts
*they don't have a digital meter but they are simple & bulletproof & have a huge service network across the USA & Canada.
**TruckFridge is the cheap, economy version
**Isotherm & Vitrifrigo have an advantage over Novakool in that they can keep ice cream, rock hard

RAUSC just purchased a Novakool R4500, I have had the R3800 for 18 months now & its been one of the best upgrades.

And very, very, very important - I can park most places up to 30% grade with zero issues - this is something you don't realise the importance of UNTIL you have been given the freedom, in a city or town, this is critical to finding parking.

Anything beyond 5%, during the summer, for more than 30 minutes using a 3 Way, is a recipe for disaster.

themexicandoctor · 12-21-2021, 07:07 PM

Quote:

Originally Posted by NW Lady

I have 400 ah lithium but no solar. I do have the old onan 2800 gen. and a 20 amp dc to dc charger. With a combo of my 45 dc panel and a separate 40 lithium plug in charger, I can get 80 amp going into batteries at same time with the generator. (There are two separate banks of batteries... 200 ah each). So I think I am ok for electricity. Looks like I need to find out more about the ventilation needs.
Thank you one and all for the info

By the way, if you have a Roadtrek thst had a 3 Way, you have abundant existing ventilation.

The Guru of Marine Refrigeration, Ron Lambda said that the amount of heat a DC Fridge puts out is infinitesimal compared to a 3 Way.

Call Novakool & or, let us know what rigyou have & I am sure there are plenty of owners here thst made the switch.

Here is the lower & upper vents with my 3 way removed - Ron the Guru who designed Custom Marine Refrigeration systems for Isotherm & for American owners of mega yachts, 6 months per year, in Italy, is the one who suggested the simplicity of Novakool.

themexicandoctor · 12-21-2021, 07:34 PM

By the way, one of best add ons you can buy relatively inexpensively is these devices that another poster turned me onto;

www.sensorpush.com

Bluetooth sensors that monitor both Temperature & Humidity & give you such detailed information both in real time & historically over time by hour, day,week, month & year.

I have one in my Freezer (in a sealed bag), one in my Fridge on the walk & then 5* more throughout the van.

Goes straight to my Cell Phone.

*long story

NW Lady · 12-23-2021, 02:24 AM

Thank you one and all for all the information. I am definitely feeling more confident that switching to a danfoss compressor is a good idea even though my current dometic is only about 4 yrs old and works as good as when new.

I have a 1999 Ford coachman van E250. The fridge is about 3cf.

Ventilation - typical access panel at bottom of unit and top vent panel. Would it work to just leave those as they are for ventilation and just put more insulation about the back and maybe sides of the danfoss unit?? Or... is it ok to block off some of that for better insulation against heat and cold?

NW Lady · 12-23-2021, 02:26 AM

Mexican Doctor.... thanks you so much for your help here and in another topic. I like that sensor you mention. I have my own funky solution but like your MUCH better. I think it is a Christmas gift to myself !

NW Lady · 12-23-2021, 02:39 AM

RLUM - you mentioned you are waiting for the compressor and that you "ordered vitrifrigo components". Thought the compressor was part of a refrig. ...but not with vitrifrigo?? Is there an advantage to ordering components separately?

themexicandoctor · 12-23-2021, 06:07 AM

Quote:

Originally Posted by NW Lady

Mexican Doctor.... thanks you so much for your help here and in another topic. I like that sensor you mention. I have my own funky solution but like your MUCH better. I think it is a Christmas gift to myself !

I have received so much help here. In fact I must have a few multi page threads about Solar, Electric & then DC Fridges where at times, spirited discussion produced the Diamonds I needed.

As it is, I do not know anyone who has made a switch from a 3 Way to a DC unit, that would ever go back.

But buy one of the top three.

In fact I think Booster created such a survey.

As to defense of what you already own, once you pull it out & burp it for 48 hours, it will be a new fridge. Mine is now enjoying its retirement in a cabin in the hills, completely level & stable.

3 Way Fridges, even if you have Jerry rigged them with extra cooling fans, simply don't keep up with consistently high summer temperatures, just when you need them.

Then there is the issue of the sun hitting that side of the rig, more problems.

Add into the mix even 5% off level parking for any period of time & its a no win situation plus you place yourself at risk of getting sick.

Love the Sensorpush, I have one of them on the outside of my rig so I can tell if my 4th wife is getting within 50 miles of my location & give me ample warning to move.

themexicandoctor · 12-23-2021, 06:12 AM

Quote:

Originally Posted by NW Lady

Thank you one and all for all the information. I am definitely feeling more confident that switching to a danfoss compressor is a good idea even though my current dometic is only about 4 yrs old and works as good as when new.

I have a 1999 Ford coachman van E250. The fridge is about 3cf.

Ventilation - typical access panel at bottom of unit and top vent panel. Would it work to just leave those as they are for ventilation and just put more insulation about the back and maybe sides of the danfoss unit?? Or... is it ok to block off some of that for better insulation against heat and cold?

Booster is an extreme Engineer, he might add extra insulation, etc but only because he is Booster.

If NASA were to give the Space Shuttle to him for the week he would have dismantled it, improved most everything & handed it back just because.

If you had a 3 way in there before, you have an abundance of ventilation built in.

I wonder if there is a thread/forum dedicated to your 1999 Ford Coachman - in it you will probably find someone who has already made the switch to a DC unit - this is what I found on this Classbforum.com;

https://www.classbforum.com/forums/s...archid=2434422

themexicandoctor · 12-23-2021, 06:33 AM

Here is an excellent article thst skims over what you are looking for;

https://www.mortonsonthemove.com/12-...-refrigerator/

Note that they did a JC Refrigeration* upgrade & then went with Dometic** DC Unit.

*this is an Amish company that retrofits large units only to their technology only ie; size 6 cu feet units, plus. Not our small units.

**the Mortons are the RV Equivalent of Influencers, so I have a degree of hesitation especially when they went with a company that I personally experienced as tone deaf to the needs of RVers, especially when it comes to Refrigeration.

**plus if you talk with the majority of RV Repair Facilities, you will discover that Dometic were poor to work with in the past and are now considered a nightmare to deal with, even with the access of Service Provider.

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