How does the refer work?

Refrigerator, stove, furnace, water pump, air conditioner, microwave, water heater, fans, lighting
Post Reply
User avatar
Mark
Seasoned Traveler
Posts: 177
Joined: Tue Mar 25, 2014 3:03 pm
B190 Year: 1997
WBCCI: 0
Location: I get my mail in Carson City, NV

How does the refer work?

Post by Mark »

So how does the refer stay powered? If I’m plugged in to shore power, sure, no problem. What about 12v? Won’t that eventually drain the battery? You can’t just turn off and on the refer, you have to run it a while to cool it down and then keep it cooled down don't you?

On my way home from Yosemite, I put the thing on 12v and drove for several hours. The freezer was cool and the refer was merely “not warm”. Does it take longer than that to cool down or is that as good as my refer is going to get?

The reason I ask is that it seems to me that without lots of available power (plugged in or solar) using the refer is sort of a non issue, it simply ain’t gonna work.

Can I run it on the propane while I’m driving the car? While it’s sitting in one spot for a few days? How long does it take to empty the tank?
If it ain't fun - it ain't done!
FoCoKCCO
Weekend Camper
Posts: 36
Joined: Wed Jan 15, 2014 8:15 pm
B190 Year: 1993
WBCCI: 8008
Location: Fort Collins, CO

Re: How does the refer work?

Post by FoCoKCCO »

I've learned that the fridge will at most just maintain temp while using the 12V mode (which only works with the engine running). This is my first season with my van but I have had the same tank of propane and haven't had to refill it yet after running the fridge for total about 6 days. It uses a very small amount of propane.
1993 B-190
WBCCI: 8008
Fort Collins, CO
Mgittrich
Seasoned Traveler
Posts: 103
Joined: Wed Jul 24, 2013 9:01 pm
B190 Year: 1993
WBCCI: 0

Re: How does the refer work?

Post by Mgittrich »

The refrigerator doesn't work very well in 12v mode. The food must be already frozen and cold in the chill box and the outside temps are 70 degrees or less for the refrigerator to maintain anything approaching normal. I have a wireless thermometer I keep in the freezer and fridge to keep an eye on it without opening the door. On the Oregon coast where the temps are around 60 degrees 12v works ok if you follow the previous conditions I laid out.

It is not recommended to travel with the refrigerator running on propane. There is a fire risk. Having said that I have done it many times without incident. With a full propane tank you should be able to run the refrigerator for at least 30 days.

I would also point out that these old dometi's just don't work very well in warm/hot temps over 85 degrees.

I hope this helps.


Mike
User avatar
Mark
Seasoned Traveler
Posts: 177
Joined: Tue Mar 25, 2014 3:03 pm
B190 Year: 1997
WBCCI: 0
Location: I get my mail in Carson City, NV

Re: How does the refer work?

Post by Mark »

Thanks.

Next summer I'm going full blown solar on my rig. I may replace the refer with an Isotherm http://www.indelwebastomarineusa.com/ho ... epage.html this year.
If it ain't fun - it ain't done!
User avatar
Kentuckian
Seasoned Traveler
Posts: 346
Joined: Sun Sep 30, 2012 3:52 pm
B190 Year: 1993
WBCCI: 0
Location: Kentucky, USA

Re: How does the refer work?

Post by Kentuckian »

This is a timely topic! I just did a 10 hour drive between Kentucky and Kansas in 90 degree temperatures. My Norcold fridge compartment temp raised from 36 degrees (120v overnight) to high 50s while running on 12volt during our drive. When I got home I got out my test meter and was dissappointed to find that all was well with the 12 volt circuit.

I just picked up one of those D cell battery powered fans to go inside the fridge compartment to circulate air. We also bought a box of narrow zip lock baggies and froze water in them making something like popsicles. We are going to try the fan and pack the ice bags around our per-chilled food on our next outing. I've got another 10hour drive coming up soon so we'll see how that works. The idea would be to use the ice bags during the day and refreeze them at night while plugged into 120v.

There is very little discussion on the web about this issue. The one thing that I have seen that make some sense is to install a 12 volt fan to blow air up the back side of the fridge and out the top vents. I did not read anyone using this while driving. However, several people talked about this being effective while boondocking in hot weather.

While driving, I imagine that the air pressure on the sides of the van plays havoc with the normal convection air circulation on the back of the refridgerator. Adding a fan 12 volt fan may be a good way to assure air flow across the heat exchanger fins at the top of the refridgerator?

Or for a no power option, I wonder if one could fashion an air scoop to mount over the lower vent, to draw in air, increasing air flow into the chamber and out the top vent?
1993 Airstream B190
twistedskipper
Weekend Camper
Posts: 45
Joined: Fri Apr 04, 2014 10:10 am
B190 Year: 0
WBCCI: 0
Location: Longmont, Colorado

Re: How does the refer work?

Post by twistedskipper »

Just for general interest, I found these specifications for the original Dometic RM2310 and the currently available drop-in replacement Dometic RM2354:

Original RM2310:
AC watts 160 (1.3A)
DC watts 125 (10.4A)
LPG BTU 750 (although the sticker on my refrigerator says 1000 BTU - either mine is a slightly updated unit or maybe they mean 1000 BTU input & 750 BTU output?)

Newer RM2354:
AC watts 175 (1.5A)
DC watts 150 (12.5A)
LPG BTU 1000

Dometic has evidently upgraded the cooling capability of this model family at some point in time, in all modes. I wonder if the higher-wattage electric elements could be installed in the older refrigerator, especially the 12v element?

These specifications seem to also explain why the cooling capability will be less on DC mode than on AC mode on either unit. I'm not sure how to compare the cooling capability specifications for LPG mode vs. either of the electric modes.

EDIT: I did just look up BTU - Watts conversion, and it looks like a 750 BTU gas burner might be the equivalent of a ~220 watt element. If this is true, then running the refrigerator on LPG should have much better best cooling performance (assuming the cooling unit can absorb the additional heat rather than letting it just go up the flue).

By the way, the Norcold N300.3 refrigerator specifications are:
AC amps 1.5 (165-180 watts @ 110-120v)
DC amps 12 (144 watts @ 12v)
LPG BTU ??

From the specifications, it's likely that the Norcold N300.3 and Dometic RM2354 should provide similar cooling performance. Either unit should provide improved cooling over the original RM2310, but I don't have any personal experience with this.

My RM2310 has performed quite acceptably on LPG or 120v, freezing the refrigerator compartment if set to MAX, but I don't have it working yet on 12v (for driving).
Last edited by twistedskipper on Fri Jun 27, 2014 4:57 pm, edited 3 times in total.
--
Tim
1999 B190
twistedskipper
Weekend Camper
Posts: 45
Joined: Fri Apr 04, 2014 10:10 am
B190 Year: 0
WBCCI: 0
Location: Longmont, Colorado

Re: How does the refer work?

Post by twistedskipper »

It looks like the Isotherm line of refrigerators are all compressor models, as one would expect for marine applications (hard to keep a refrigerator level on most boats). On our boat, the compressor noise was noticeable, but not annoying. The bigger drawback that I see for RV use is you could never be off shore power or generator while camping with food in the refrigerator, since there'd be no LPG mode. Unless, of course, you increase your house battery capacity and/or add enough solar power to cover the compressor drain.
--
Tim
1999 B190
User avatar
skater
Site Admin
Posts: 2569
Joined: Thu Mar 08, 2007 1:00 am
B190 Year: 1991
WBCCI: 13270
Location: Annapolis, MD

How does the refer work?

Post by skater »

I think the reason it's not discussed much in general is that the B190s are at a particular disadvantage since they mount the fridge directly over the rear axle, giving it a bunch of extra heat to contend with. When I was using the rooftop A/C on the road with the generator, I'd run the fridge in electric mode, too. Gas mode would work as well, although there's a very minor chance of a gad leak if you get in an accident and the regulator fails (it happened to someone over on AIR forums). Our fridge in the trailer keeps food cold much better, and I think part of the reason is just that it's not exposed to the temperatures the fridge in the B190 was. It's also relatively new, though, so it probably works better in general.
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
User avatar
Mark
Seasoned Traveler
Posts: 177
Joined: Tue Mar 25, 2014 3:03 pm
B190 Year: 1997
WBCCI: 0
Location: I get my mail in Carson City, NV

Re: How does the refer work?

Post by Mark »

I used the fridge on propane on a trip last weekend and was pleasantly surprised!

We put a bag of ice in the freezer, (for drinks) and in the two pretty hot days were were out, it didn't melt at all. The refer kept things cool enough. Pretty psyched about that, I didn't really feel like I wanted to replace it this year.
If it ain't fun - it ain't done!
jb1rd73
Seasoned Traveler
Posts: 152
Joined: Fri Mar 28, 2014 9:30 am
B190 Year: 1994
WBCCI: 0
Location: Vail Valley Colorado

Re: How does the refer work?

Post by jb1rd73 »

you put it in a pipe and smoke it :D But to answer question, I ran my fridge on propane from Florida to Colorado and it worked great, I pre cooled it on 120 before we left and stuck a gallon jug of frozen water in to help out, worked great, as the water in the jug melted I had nice ice cold drinking water!!!!
User avatar
Mark
Seasoned Traveler
Posts: 177
Joined: Tue Mar 25, 2014 3:03 pm
B190 Year: 1997
WBCCI: 0
Location: I get my mail in Carson City, NV

Re: How does the refer work?

Post by Mark »

jb1rd73 wrote:you put it in a pipe and smoke it :D
LOL, I just got it! HA! :mrgreen:
If it ain't fun - it ain't done!
wineranger
New User
Posts: 1
Joined: Mon May 25, 2015 1:34 pm
B190 Year: 0
WBCCI: 0

Re: How does the refer work?

Post by wineranger »

Mark wrote:I used the fridge on propane on a trip last weekend and was pleasantly surprised!

We put a bag of ice in the freezer, (for drinks) and in the two pretty hot days were were out, it didn't melt at all. The refer kept things cool enough. Pretty psyched about that, I didn't really feel like I wanted to replace it this year.
----------------------------------------------------------
Hi--just bought a 1996 B-190 recently. Regarding the refrigerator running on propane, mine works great via electric plug in, but how do you know the unit is on via propane? Instructions say you can see the pilot light via "the reflector." However, I cannot see anything in that space. I *think* I have the unit on and cooling...doing a test over the weekend.
Mgittrich
Seasoned Traveler
Posts: 103
Joined: Wed Jul 24, 2013 9:01 pm
B190 Year: 1993
WBCCI: 0

Re: How does the refer work?

Post by Mgittrich »

The reflector will show a very faint blue flame when it is on. It is almost impossible to see it if there is any light in the RV. You can close all the curtains and hope it is dark enough or check at night when it is dark in the RV. Another way to get an inferred "on" signal is to place a wireless thermometer in the top refer vent space and monitor the temp. When it is running the temp will be higher then outside air temp if you are not moving. Generally my refer temp runs 90 - 110 degrees F when it is running.

I hope this helped. The lack of a really good "on" indicator in these old refers is annoying.

Mike
User avatar
lido14co
Seasoned Traveler
Posts: 259
Joined: Wed Apr 25, 2012 1:12 pm
B190 Year: 1992
WBCCI: 0
Location: Los Osos, CA

Re: How does the refer work?

Post by lido14co »

You can also open the access panel on the outside of the van and carefully feel to see if the gas jet is lit


Sent from my iPhone using Tapatalk
Post Reply