Ours is in a 2006 Pleasure Way, we bought last year.On our recent trip we were generally on AC at night, DC while driving and propane while parked during the day.We rotated blue ice packs from freezer to fridge through the day ( freezer always stayed below 28ºthe fridge would go as high as 44º some days...then cool at nightThis has a single 100CFM fan mounted under the fins.Now that we have returned, I bought a bunch of 3" fans, each is good for about 50 cfm.I have mounted 4 of them pushing out the top vent- party obstructed but moving good air out the top, which draws in pretty good from the bottom.running on ACambient temps are maybe 88º at 6 am, 100 by 10 am and peaking at 110 at 3 pm, staying above 100 to about 9 pm ( the van windows are open as we work on our homemade screens and vent fan is on- the van is close to ambient temps)charting through the day with van parked beside the house ( level) and a harbor freight "carport" kit providing pretty good shade, I am charting generally 55º to 60º cooling below ambient.the fridge is empty- I know that with goods in it the temps should be more stableCompared to other dometic 3n1's- how am I doing- fair, good, great?thanks, Mike

Just curious why the swapping between different modes...........testing :HAC at night, DC while driving, Gas during day while parked.DC is the 'worst' method for cooling.....IF you are maintaining freezer at 0*F to -5*F and food section at 38*F to 42*F fridge is doing as well as any absorption fridge.(Temps measured using thermometer in glass of water)

mkguitar wrote:On our recent trip we were generally on AC at night, DC while driving and propane while parked during the day- sorry if there is an image added to your post, I cannot see it.AC power at a campground...DC while driving and propane when parked for any length of time ( better cooling/save batteries).2.) fridge temps will be dependent on ambient temps.being in the Southwest our avg ambient temps through a 24 hour period may be 30 or 40 degrees higher than Maine or Midwest.Being in PHX, I'd guess we are 10 or 15º higher than yours in Verde ValleyIf you can suggest a different way to test I'd be interested in your experienceMike

mkguitar wrote:If you can suggest a different way to test I'd be interested in your experience Try it a time or two with skipping the DC part. That likely is the most inefficient mode, followed closely by AC.I just leave mine on propane all the time. Cools good, doesn't use much gas and a tiny bit of battery.I would use AC only after getting it good and cold.....where shore power is available. It takes mine a good 8-10 hours to get noticeably cold when on AC. Only a couple of hours on propane.All of your messing around with fans probably isn't really helping much and might be counter-productive. Are these fans being used inside the fridge or outside ?? 100CFM is WAY overkill for inside......and probably mild overkill for the external part too.More is not always better.

well the past few days have shown that on AC the fridge will stay 55º or so below ambient.when it is 110º that's not cold enough. but it is when 90º( so even if at a campground with AC power and airconditioning on- we may see better fridge temps as the van will be cooler, less heat soak on the fridge)when powering up, drop in temps of about 6º each hour until we cannot cool any father.this morning at 10am it was 100º and fridge was at 40º....switched to propane and no huge advantage so far over the ac.( the past 5 hours)I'll watch this for a couple of days.In propane mode I am starting at single fan with heat switch ( as when we bought it)then will try with my 4 fan package.possible too much air flow could affect the propane heating, we'll see before/afterMike

Do you have a circulating fan of some type inside? When loaded with stuff you will not get much natural convection past the cooling fins inside, and even a small circulating fan will improve things. I have a computer fan wired into the hot side of the light switch so it runs as long as the fridge is on. It helps cool down faster and returning to cool after opening, it uses very little power and is one of the best mods I have done. Even in summer temps here in the SoCal desert it will maintain in the safe zone for food on propane, which puts out more btu than the electric heater thus more effective. Check and be sure the fridge is properly baffled by looking up from the outside panel. There should be only around an inch of space between the coils and the wall to create the chimney effect. If not, you will need to fill it somehow.

Dometic 3n1 absorbtion- what's realistic ? | Good Sam Community

19 Replies

mkguitar
Explorer
Sep 05, 2015
with the 2 fans exhausting ( side by each) mounted to the left side of the top vent I have managed to keep temps below 37º the past 24 hours.

Our ambient temps have dipped with a storm system moving through- but close to 100º most of the day- and no lower than 84º.

so I am getting cooling about 65º below ambient on AC- this is a slight improvement.

I have to look at the propane- It doesn;t seem to cool markedly better than the AC.

I have cleaned the vent and hanging baffle- there was not much in the way of carbon.
Next step will be to examine the jet and make sure it is correct size for our model and check the thermocouple.

...which I have just done- everything I looked at was clean, but i cleaned anyhow- the gas controls work as expected and the thermocouple put out 34mVDC...right within spec.
Fun little project.

We plan on heading out mid-week after everyone is back from their long week end

easy to do this while we are home, rather than scratching head in a campground.

mike
GaryKH
Explorer
Sep 05, 2015
My wife is good at keeping the temps at around 40 in 100+ weather. She uses 2, 2liter (quart) plastic milk jugs & rotates them every day from the freezer to the fridge. This makes the whole system work like a regular cooler in addition the fridge. I do my part by either having the van in the shade, or providing temporary shade for the fridge vents (with air flow).
Vulcan_Rider
Explorer
Sep 05, 2015
mkguitar wrote:

It may well be that 4 fans are better for AC operation,

4 fans is just gross overkill, regardless of the mode of operation or the environmental conditions.

IF you have them blowing in series, any more than one is a total waste.
bsinmich
Explorer
Sep 05, 2015
One thing I have used is to get a couple pieces of dry ice to help the initial cooldown.
mkguitar
Explorer
Sep 04, 2015
Sorry if that wasn't clear, In the 1st post I described 4 x 3" fans pushing out the top vent.

What I am up against are our high ambient temps from May to Mid September over 100º with about 20 days over 110º. Our low temp is typically still above 85º

I'm trying to get the best I can out of this for our climate- get predictable results under various conditions.

It may well be that 4 fans are better for AC operation, and 1, 2 or none fans are better for propane operation- I'll find out.
DC doesn't really figure into this as air flow from driving will be the largest variable

and add to that the method of rotating frozen stuff to the fridge area to help stabilize temps

Mike
Vulcan_Rider
Explorer
Sep 04, 2015
mkguitar wrote:

I am wondering if the 4 fans are too much and the airflow is interfering with the propane heating the fluid.

I think I said that already.
And asked where the fans were located.....but you never responded to that.
I have no real problem with mine.....with ZERO fans. I can't see ever thinking that more than 2 (one inside and one outside) would be of any advantage but sometimes things just get stuck in our brain it seems. ;-)
mkguitar
Explorer
Sep 04, 2015
As of now- on AC mode consistrntly 55 to 60º below ambient is possible with the 4 fans I added.

However the propane is not cooling well- or as well as I think it should.
I am wondering if the 4 fans are too much and the airflow is interfering with the propane heating the fluid.

so the MKII version is now just 2 fans, and placed at the end farther from the propane.

Running AC mode today and cooling seems to be about as good- but hard to tell we had a couple of storms come through today and the ambient temps were not stable.

I'll see how the AC does, then switch to propane mode and see how that is.

Mike
cbigham
Explorer III
Sep 01, 2015

I leave mine on gas, occasionally rotate frozen soup or drinks from the freezer to the top shelf in the fridge. Things that must be kept cold I put on the bottom.
mkguitar
Explorer
Aug 31, 2015
Yes, I saw your post on that somewhere...

Luckily we are in the habit of putting the same things in the same places in the fridge so a quick grab and shut.
And that does help with the fridge temps

Mike
stan909
Explorer
Aug 31, 2015
My fridge works pretty good but my wife does not. Where I try to grab stuff quick and close it , she leaves open far too long and the poor thing is no match for her.