Dometic 3n1 absorbtion- what's realistic ?

[mkguitar]

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 28º
the fridge would go as high as 44º some days...then cool at night

This 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 AC

ambient 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 stable

Compared to other dometic 3n1's- how am I doing- fair, good, great?

thanks, Mike

[PUCampin]

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.

[mkguitar]

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/after


Mike

[Vulcan_Rider]

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.

[mkguitar]

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 Valley

If you can suggest a different way to test I'd be interested in your experience

Mike

[Old-Biscuit]

Just curious why the swapping between different modes...........testing :H
AC 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)