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-   -   Simple Survey on Fridge Performance While on Propane (http://www.airforums.com/forums/f404/simple-survey-on-fridge-performance-while-on-propane-169937.html)

OTRA15 07-29-2017 04:48 AM

Thanks Bborzell for the update. What were the ambient outside air temps during that overnight reading, and while on the road?

A solution which takes the fans out, and relies on thermal convection to get the hot exhaust air out, will remain a cruel joke -- in my opinion -- with the propane cover continuing to provide a nearby and substantial physical obstruction to air flow.

Moreover, this "solution" does nothing to cover uncle bob's questions about air pressures/vacuums on the front of the Basecamp while towing.

What does Jackson Center say about the cooling-while-towing air pressure factors? Please get in the face of everyone in the chain-of-command there, and ask the difficult questions! If you have left already, please continue to hound them if/when your fridge fails to perform in challenging weather, towing and sun conditions, as I am sad to suggest will probably happen. :(

As mentioned many times, we were thinking of downsizing to the BC, as will many Airstream baby-boomers IMO, but with the current FUBAR fiasco, that will never happen.

Airstream and Thor need to wake up here, and cop on to the full extent of this problem. [IMO]

:angry::wally::angry:


Thanks again for the detailed post.

Peter

OTRA15 07-29-2017 06:02 AM

Wondering if you have been monitoring this fridge thread, and might have some feedback from the company on the cooling-while-towing issues raised by uncle bob's Post #40 [and subsequent posts], which is quoted below?

Thanks,

Peter


Quote:

Originally Posted by AirstreamInc (Post 1948686)
. . .
Here's more info on the service bulletin regarding the refrigerator vent that we posted earlier in the week on the forums. Let us know if you have any questions!
<snip>
Airstream apologizes for any inconvenience. Customers requiring additional information may contact Airstream Customer Service and Technical Support at 1 (877) 596-6111, option 2.



[click on arrow in quote to go to uncle bob's Post #40]
Quote:

Originally Posted by uncle_bob (Post 1984267)
Hi

Here's yet another problem / question to toss into the pile:

When moving, air flows over the TV. It then hits the front of the Basecamp. My guess is that it flows *down* over the front of the trailer in the area between the propane tank cover and the trailer. It then exits under the trailer. (= high pressure just above the propane tank cover). A "tall" TV would create a different pattern than something like a sedan hatchback. Yes, with a big automotive wind tunnel or a copy of FloEFD you could dig further into this.

If the air *is* doing this, pulling the trailer is actually *worse* than having it sit stationary in the driveway. Even with fans, you have a limited back pressure range. At some point, the air simply stops moving. It's not just an issue if you are relying on convection.

Bob


uncle_bob 07-29-2017 08:01 AM

Hi

The gotcha with my "nutty theory" is that it also is TV dependent. Pull the trailer behind a pickup with a tall shell on it and you get one situation. Put it behind a Mini Cooper and you have very different flow. In between those two are a whole variety of cases. Convection is *not* very powerful in terms of moving air in a situation like this. Small changes can be important.

Bob

Bob

OTRA15 07-29-2017 09:37 AM

Exactly.

Even when parked in a campsite, a decent wind blowing on the front of the Basecamp will easily reverse the convection, and push the exhaust air back into the fridge's mechanical space!

Even a child could foresee this . . . :(

What will the next few Band-aids be, now that the fans are being yanked out, before someone wakes up and directs a strong wind at a new BC, and monitors the fridge's interior temp on LP when there is a positive pressure on the front, which by the way, will create a strong vacuum on the downwind end of the trailer. With that squared-off stern, the vacuum will be significant for sure.

Has Airsteam done any wind tunnel testing during the design of the new Basecamp? With very simple calibration, atmospheric pressures at several locations would be very easy to measure.

Have you noticed the way that commercial trucking companies have been adding wind-control panels in all kinds of locations to make the air flow for a semi-trailer rig more "laminar" and thus more fuel-efficient? [between the tractor and trailer, under the trailer near the rear wheels, on top of the tractor to push the air up as high as the trailer, etc. etc.] This ain't rocket science!

Come on JC, you can do it! The only way natural convection works for hot fridge exhaust gases -- is to vent them up a flue, through the roof, like you did all along in the 1950's, 1960's, 1970's, 1980's and so forth.

It wasn't broken so why "fix" it with myopic re-designs?

Have a good weekend.

Peter




:wally:

Troutboy 07-29-2017 10:03 AM

Simple Survey on Fridge Performance While on Propane
 
Wow. That's cool bborzell. Hope this fish is permanent and all you BC folks can put this behind and camp on.

. Any chance you have pictures to post of the fix?

FricknFrack 07-29-2017 10:25 AM

I did a two-day refrigerator test on propane only. Our BC is sitting in the RV storage lot in full sun in PC, UT. I stopped by on way home from work three days ago and turned on power, propane and fridge. Put a glass thermometer on bottom shelf and digital thermometer on middle shelf nothing else on in the BC. Came back next morning at 8a - below are the data

Outside temp Refrigerator temp
Day 2
8a 65 40
6p 85 66

Day 3
8a 67 42
6p 84 55

Glass thermometer temps was nearly identical to digital thermometer temps and they were on different shelves so temps are accurate. The freezer freezes and is always frozen no matter what outside temp is even when inside fridge temp was 66deg.

Conclusion:
1) the refrigerator does not maintain sufficient cold temp to safely store food when running on propane when ambient temp is above mid 70s degrees.

2) the freezer clearly is capable of keeping temp below 32deg even in hot temps above mid 80s.

I don't have electrical to plug into at my RV storage to do same test on shore power.

At this point, I'm thinking the small metal cooling fins in the refrigerator are just not good enough to maintain safe food storage temps in anything above 70s deg ambient temp. The freezer freezes and stays frozen so the fridge works - just bad design??? At this point I'm thinking of taking the freezer door off and maybe it will keep whole rest of the refrigerator cold enough. I don't really need to freeze things anyway

Follow-up after calls to AS warranty in Jackson and AS UT dealer - they both acknowledge many reports of poor fridge performance. They have a fix - two additional fans and insulation around the main box. Scheduled to bring it in to UT dealer in couple of weeks n told them I need back within 2 days or taking back anyway. No 6 weeks sitting around waiting for parts this time!

OTRA15 07-29-2017 10:32 AM

Quote:

Originally Posted by FricknFrack (Post 1985158)
. . .
. . . They have a fix - two additional fans and insulation around the main box.
. . .

Stop the presses! According to Bborzell in Post #59-- direct from Airstream's base in Jackson Center -- the fans are out and thermal convection alone is going to fix things up just dandy . . .

:blink:

Thanks for your detailed report, and good luck!

Peter

PS -- It will be interesting to see how long it takes for "no more fans" to filter out to the dealers and sales people. Speechless here . . .

OTRA15 07-29-2017 10:36 AM

Quote:

Originally Posted by Troutboy (Post 1985148)
Wow. That's cool bborzell. Hope this fish is permanent
. . .

Hey I know you have trout on the mind, but let's not add any permanent fish to this beleaguered fridge situation!

:lol:

Troutboy 07-29-2017 11:33 AM

Quote:

Originally Posted by OTRA15 (Post 1985164)
Hey I know you have trout on the mind, but let's not add any permanent fish to this beleaguered fridge situation!

:lol:



[emoji33][emoji226][emoji226][emoji226]

uncle_bob 07-29-2017 11:41 AM

Quote:

Originally Posted by OTRA15 (Post 1985140)
.....

Has Airsteam done any wind tunnel testing during the design of the new Basecamp? With very simple calibration, atmospheric pressures at several locations would be very easy to measure.
......

:wally:

Hi

"Automotive" wind tunnel testing is not easy. You need a facility that gives you a moving surface under the vehicle as well as the "wind". Without the moving surface, you don't get the real picture. Net result - it's easier to instrument up something like a Basecamp and tow it around to check something like this.

Bob

Gail Miller 07-29-2017 11:43 AM

Quote:

Originally Posted by Bborzell (Post 1985050)
We showed up at Jackson Center this morning. In addition to the fridge issue we took the opportunity to get a few other small issues addressed.

My service tech was Joel. If you should show up for service at Airstream and you draw Joel, you should have a good day. He is everything that today's service folks have failed to aspire to. Thoughtful, attentive and skilled are three important attributes and he has them all.

The fix considered that the fridge creates heat that fills the cavity between the unit and the front wall. Much at that heat fails to exhaust itself through the forward vent because it has the upward path which heats up the counter top.

As I understand the issue, AS engineers got together with Dometic engineers and decided to limit the volume of space available for the heat to fill. Instead of adding fans (Joel pulled the noisy fans that were initially added) Joel placed deflectors between the fridge and the forward vents. They also insulated a top deflector that is supposed to eliminate the hot countertop.

In effect, the design should fill the considerably smaller space which has been created by the deflectors. In addition, itappears that the deigners sought to take advantage of the expansion of the heated air to drive movement from the fridge through the deflectors andout the vent.

By the time we were walked through the fix by Joel, the fridge had cooled fromthe low 50s to 43. Two hours later it was at 40 and, after 3 hours on the road, it was 37.

Joel says that ours ws the first to get the redsign in the service department. However, all the new BCs are seeing the mod.

Tomorrow, we will get more heat and I will continue to monitor temps. So far so good, and no fan noise.

So 'Joel' is at the Airstream factory in Ohio and this is what AS did on the 2018 Basecamp to fix the fridge problem? Why is AS still sending out fan kits if this is the fix. Please keep us posted on how this works on your continued trip. Grrrr

FricknFrack 07-29-2017 11:55 AM

Quote:

Originally Posted by Gail Miller (Post 1985196)
So 'Joel' is at the Airstream factory in Ohio and this is what AS did on the 2018 Basecamp to fix the fridge problem? Why is AS still sending out fan kits if this is the fix. Please keep us posted on how this works on your continued trip. Grrrr



Good to know and will be sure my AS dealer is on board with any modifications to the fix before they get started - don't need to make multiple trips to try to fix this problem [emoji849]

Gail Miller 07-29-2017 11:59 AM

Quote:

Originally Posted by FricknFrack (Post 1985203)
Good to know and will be sure my AS dealer is on board with any modifications to the fix before they get started - don't need to make multiple trips to try to fix this problem [emoji849]

My thoughts exactly. I spoke with Gretchen at AS on the 7/17 and she is sending fans to my dealer. I don't want fans if fans aren't the fix.

Bborzell 07-30-2017 09:44 AM

It didn't work...
 
Where to start?

When we left Jackson Center, after the fridge fix, the fridge had been on shore power for the amount of time that transpired between Joel buttoning up the fridge after the fix and when we pulled out heading for northern Minnesota.

The fridge was sitting on 43 degrees and within a couple of hours, it was 37. Things were looking good.

By the time we got to Madison, Wisconsin, it had crept up to 43 and by last night when we pulled into northern Minnesota, it was sitting on 48. The glitter had faded and we tossed the food.

We plugged in at our friends place in Minnesota about 8 pm and by 8 am this morning, the freezer was on 0 and the box was 36.7.

A few takeaways from this series of unfortunate events...

After 4,800 miles and a week on the road, the fridge debacle has not diminished our satisfaction with the rest of the Basecamp. All the systems work as designed, it tows like it isn't behind the Jeep (no, really), the Thermarest pads make the sleeping surface work well and it just plain fits all of our original expectations as well as our real life needs.

That said, the fridge does not work reliably on propane; period. It didn't work as originally designed, it doesn't work with the added fan fix and it doesn't work with this most recent fix. I don't know whether driving at highway speeds actually exacerbates the cooling deficiencies, but I highly suspect this to be the case.

Contrary to our eastern leg which was quite hot >90 degrees most of the time, the trip from Jackson Center to Minnesota has been much cooler, but still the fridge can't provide venting needed for adequate cooling under propane.

Here's an interesting thought. If you start out your driving day after the fridge has been sitting overnight on 120V and has reached 37 or so degrees, one would think that the box would be able to maintail a food safe level of 40 degrees for up to 4 driving hours even if it has no power to it; just like a not particularly efficient ice chest. So, maybe the propane part of the equation actually creates the temp rise while driving as the pilot flame introduces heat that would otherwise not be there. So, if you are on the road and can get adequate cooling while plugged in and need to drive <4 hours os so, you might be better off turning off all power to the fridge while driving; just a thought.

As frustrating as the fridge thing has been, I believe that this will pass after AS has enough real world feedback to overcome the shortcoming of the modeling that lead to the original fridge install design. Lacking any contrary info, I am back to thinking that someone needs to try a 2 way fridge that is either 120V or 12V, but not propane.

People who drive no more than a few hundred miles a day probably won't even know that they are heating up the cabinet while on propane. The real failing will come with boondockers who go days without 120V power to bail them out. I'm guessing that the percentage of Basecamp buyers who end up totally off the grid is going to be similar to the percentage of FWD SUVs who drive off road.

I just went out to recheck the fridge before hitting "send" since the trailer has been sitting in full on morning sun onto the front end. It has actually dropped another .7 degrees.

OTRA15 07-30-2017 11:05 AM

Quote:

Originally Posted by Bborzell (Post 1985623)
. . .
. . . I don't know whether driving at highway speeds actually exacerbates the cooling deficiencies, but I highly suspect this to be the case.
. . .

Bingo!

Sorry for your continuing problems. The fix here is a total re-design which gets the fridge over to the side of the BC including a flue through the roof IMO.

:bb:

Good luck all!

Peter

PS -- At the risk of belaboring the point, the problem is not all that complicated.
Most experienced RV folks can understand it intuitively.
[Click on arrows in quotes to go to these posts:
Quote:

Originally Posted by uncle_bob (Post 1985109)
Hi

The gotcha with my "nutty theory" is that it also is TV dependent. Pull the trailer behind a pickup with a tall shell on it and you get one situation. Put it behind a Mini Cooper and you have very different flow. In between those two are a whole variety of cases. Convection is *not* very powerful in terms of moving air in a situation like this. Small changes can be important.

Bob

Bob

Quote:

Originally Posted by uncle_bob (Post 1984507)
. . . I suspect the "airflow in motion" with some TV's is down over the front of the trailer regardless of the propane cover or even without the bottles.
. . .


Quote:

Originally Posted by OTRA15 (Post 1985065)
Thanks Bborzell . . .
. . .
. . . Moreover, this "solution" does nothing to cover uncle bob's questions about air pressures/vacuums on the front of the Basecamp while towing.
. . .

Quote:

Originally Posted by OTRA15 (Post 1984353)
Bob, the frontal air pressure/vacuum issues you raise demand that the fridge vent move entirely to the side IMO. Yes, a total redesign . . . IMO.

Quote:

Originally Posted by OTRA15 (Post 1985140)
. . .
Even when parked in a campsite, a decent wind blowing on the front of the Basecamp will easily reverse the convection, and push the exhaust air back into the fridge's mechanical space!
. . .



PS2 -- The worst part of this torture IMO is that Airstream seems to keep coming with fixes that are ill-informed, inconsistent, subject to recall in a day or two. Etc. Etc. Etc. . . .

Gail Miller 07-30-2017 12:14 PM

Quote:

Originally Posted by Bborzell (Post 1985623)
Where to start?

When we left Jackson Center, after the fridge fix, the fridge had been on shore power for the amount of time that transpired between Joel buttoning up the fridge after the fix and when we pulled out heading for northern Minnesota.

The fridge was sitting on 43 degrees and within a couple of hours, it was 37. Things were looking good.

By the time we got to Madison, Wisconsin, it had crept up to 43 and by last night when we pulled into northern Minnesota, it was sitting on 48. The glitter had faded and we tossed the food.

We plugged in at our friends place in Minnesota about 8 pm and by 8 am this morning, the freezer was on 0 and the box was 36.7.

A few takeaways from this series of unfortunate events...

After 4,800 miles and a week on the road, the fridge debacle has not diminished our satisfaction with the rest of the Basecamp. All the systems work as designed, it tows like it isn't behind the Jeep (no, really), the Thermarest pads make the sleeping surface work well and it just plain fits all of our original expectations as well as our real life needs.

That said, the fridge does not work reliably on propane; period. It didn't work as originally designed, it doesn't work with the added fan fix and it doesn't work with this most recent fix. I don't know whether driving at highway speeds actually exacerbates the cooling deficiencies, but I highly suspect this to be the case.

Contrary to our eastern leg which was quite hot >90 degrees most of the time, the trip from Jackson Center to Minnesota has been much cooler, but still the fridge can't provide venting needed for adequate cooling under propane.

Here's an interesting thought. If you start out your driving day after the fridge has been sitting overnight on 120V and has reached 37 or so degrees, one would think that the box would be able to maintail a food safe level of 40 degrees for up to 4 driving hours even if it has no power to it; just like a not particularly efficient ice chest. So, maybe the propane part of the equation actually creates the temp rise while driving as the pilot flame introduces heat that would otherwise not be there. So, if you are on the road and can get adequate cooling while plugged in and need to drive <4 hours os so, you might be better off turning off all power to the fridge while driving; just a thought.

As frustrating as the fridge thing has been, I believe that this will pass after AS has enough real world feedback to overcome the shortcoming of the modeling that lead to the original fridge install design. Lacking any contrary info, I am back to thinking that someone needs to try a 2 way fridge that is either 120V or 12V, but not propane.

People who drive no more than a few hundred miles a day probably won't even know that they are heating up the cabinet while on propane. The real failing will come with boondockers who go days without 120V power to bail them out. I'm guessing that the percentage of Basecamp buyers who end up totally off the grid is going to be similar to the percentage of FWD SUVs who drive off road.

I just went out to recheck the fridge before hitting "send" since the trailer has been sitting in full on morning sun onto the front end. It has actually dropped another .7 degrees.

This is all SO disappointing!!! Yuck!!!

uncle_bob 07-30-2017 01:19 PM

Hi

Based on power failures on a number of fridges over the years ..... the magic "four hour" number has a bunch of notes attached to it. In most cases the "time to destruction" on the refrigerator section will be much shorter. A tightly packed freezer section probably will make the 4 hours ...

Bob

ijustlee 07-30-2017 04:25 PM

As pointed out this is not rocket science. If I had a base camp with this problem I'd take some cardboard and tape and make a chimney up to the roof and see how the fridge works. Then I'd figure out how to make one that looked acceptable or get the factory to provide it. Or get the factory to refund me a few grand and I'd build the fix myself. The fridge will never work right unless you have good heat removal from the coils. Running on propane adds more heat to be removed so maybe an electric compressor type fridge would be the best way to go. This is another example that makes me wonder if there are any real engineers at Airstream? They seem to just have designers that draw pretty pictures. Kind of sad.

switz 07-30-2017 04:55 PM

We installed the Vitrifrigo marine DP150iL in our 2015 23D and the DP2600 in our 2014 Classic. The link below also has smaller models listed and one should be right for the Base Camp. These are freon based refrigerators with a 12Vdc DanFoss compressor which has a tiny inverter that can be plugged into shore power along with the trailer and makes the 12Vdc for the fridge. Thus there is no propane flame heating up that tiny space.

http://www.vitrifrigo.com/us/us/boat...s_and_freezers

We used three computer style fans and a blanking plate in our 23D top refrigerator vent to force the air movement in at the bottom and out at the top air vent. This system worked well while we had the stock Dometic installed along with a power switch turn the fans on and off manually. When we did the upgrade to the DP150iL, we put in a small relay so the fans cycle with the DanFoss compressor.

That literature above also shows split systems where the freon compressor could be mounted in a better heat dissipation location similar to the split A/C systems in a home.

WAcamper 07-31-2017 09:36 AM

After reading the probl ms with BC, I have been scared off on my purchase unless someone can assure AS has fixed the problem on the new ones.... so it goes.


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