Refer not maintaining temp

[Dbones]

Our new 2015 Interstat's refer will not maintain temp. The dealer wants to put in a fan and make a new vent so hot air can be pushed out from behind the freezer/refer. Thoughts? I'm very surprised the Airstream did not address this issue prior to the 2015 release.

[lewster]

You have a DC compressor fridge, and while the compressor might be susceptible to over heating, these units generally are built for marine use and as such, vent out the front mounting flange.

You might be low on refrigerant. I would have the unit checked by a factory authorized service center for the fridge manufacturer. You should be under their warranty.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[dougb]

We have the same problem with our 2015 Grand Tour refrigerator and freezer. If the ambient temp is above 70 degrees, neither will maintain the required temperature. Airstream is sending the dealer an external fan and, later, a kit to create more ventilation. They say this is needed to get the same ventilation as in the 2016 model. I've asked the dealer to check the refrigerant levels, since this wasn't a problem in May or June, though it does seem unlikely that both the refrigerator and separate freezer lost refrigerant at the same time.

[73shark]

Welcome to the Airforums. I doubt your dealer will be able to check the refrigerant level as most refrigerators do not have ports.

[Protagonist]

Originally Posted by dougb

I've asked the dealer to check the refrigerant levels, since this wasn't a problem in May or June, though it does seem unlikely that both the refrigerator and separate freezer lost refrigerant at the same time.

To satisfy the itch of curiosity, and as an aid to troubleshooting, if you run just one unit at a time, will it maintain the required temperature?

The existing ventilation was undoubtedly designed for older models that only had one Nova Kool unit installed, so one unit by itself should work just fine. If that's the case, then improving the ventilation around the coils will solve your problems.

The coils are basically heat exchangers, and work better when there is a greater difference in temperature between the coils and the surrounding air. If the air around the coils is already hot, there's no place for the heat from the coils to go.

[dougb]

Good suggestion regarding testing with only one unit running. I'll check it out over the weekend.

[grob]

I have had a related problem on our AS: the refer compressor runs continuously when it is set at level 4. The freezer does not seem to have the same problem, although difficult to know (by hearing). Nova Kool tells me that there is insufficient ventilation in our model. They are sending me a resistor that, when installed will cause the compressor to run at twice the speed (using twice the current). I have inquired with my AS dealer about a ventilation upgrade and was told today that such an upgrade is "in the works", whatever that means. The reality in boon docking is that the combined load of the 2 units is 5 amps. If they run continuously they use 120 amps (of your 180 amp total storage) in one day. So this is a significant matter.

[dougb]

Here's some follow up information to the refrigerator not maintaining temp problem on the Grand Tour:
I've been working with my dealer and Nova Kool for several weeks. I there are two problems. First, there isn't sufficient ventilation to cool both units. Nova Kool specifies 30 sq inches of inlet and 30 sq inches of outlet venting for each of the two units (I.e., 60 sq inches in plus 60 sq inches out). With the stainless steel oval vent plates installed, there might be 3 sq inches of outlet venting. When they are removed, there is about 14 sq inches of outlet venting, less than 1/4 the specified amount. Nearly the entire area above the freezer would need to be cut out to get 60 sq inches of outlet venting, and a similar amount of venting would be needed near the floor to meet the specs. It certainly won't look as stylish, which I suspect is why the appropriate venting wasn't installed in the first place. The good news is that alternative measures help, such as adding external fans to each unit, installing a speed resistor on the refrigerator (one comes standard on the freezer), and installing additional fans to push air out the top vents. I'm told that combinations of these measures have worked for others and the 2016 models are now being built with additional ventilation.

The bad news, at least for me, is that hasn't been enough for the refrigerator to stay below 40 degrees. I suspect that there is an additional problem with my refrigerator and am waiting for a replacement. The freezer works fine, with or without the refrigerator running. The refrigerator just can't do its job, with or without the freezer running, even with the outlet vent covers removed, if the ambient temp in the van exceeds 70 degrees. Part of the problem is the refrigerator is installed above the freezer and has to contend with the heat from the freezer, plus the air is hotter in the top part of the cabinet even without the freezer. I'm hopeful that a new refrigerator will solve the issue. If not, someone is going to need to develop a better, but still good looking, ventilation system for the van so that I can use it as it was intended to be used. Either that, or they are going to need to install a combo fridge/freezer in place of the freezer and retrofit a wardrobe/pantry above it.

[Protagonist]

Originally Posted by dougb

If not, someone is going to need to develop a better, but still good looking, ventilation system for the van so that I can use it as it was intended to be used.

A couple of 12v computer fans, one on the inlet and one on the outlet, should help. They're small and quiet and move a lot of air. You should be able to mount them in place of the existing vent openings with only a little bit of modification to the cabinet.


The 60 square inches you need are for natural airflow. With forced ventilation provided by fans, you can get more cubic feet per minute of air circulation through a smaller opening than you would get by the natural ventilation provided by "hot air rises" through a larger opening.

[dougb]

Thanks Protagonist. My dealer mounted a pair of those computer fans to push the air out of each of the upper vents. They also installed a larger inlet opening (but no fan). I hope these will suffice once the problematic refrigerator is replaced.

[InterBlog]

We have an on-again, off-again relationship with our Dometic refrigerator. We are breaking up permanently, but until the replacement ships in, here is a photo of our workaround - a large number of ice packs in the body of the fridge, which is the only approach that will guarantee temps in the 30's no matter what the prevailing conditions. We have an older propane fridge but from a strategic perspective, I'm not sure that matters - both the older propane and the newer electric seem to have issues with proper cooling, so this is a workaround to perhaps keep in mind.

In our case, the fridge is just not reliable. It broke a few months ago, we did two separate electronic component fixes plus one workaround, which was the installation of the external thermometer you see inset in this pic (an excellent idea that came from one of the trailer threads and which revealed the full extent of the fridge's erratic behavior).

But then it broke again in a brand new way - the Auto setting stopped working entirely (even though we just replaced that circuit board), but the fridge still worked on straight gas, but then the gas setting also stopped working, but only part of the time.

We never know when it's going to work or not work, and here's the worst part - after we spend another $700 to get a new one, I'm afraid that one won't work either, because I suspect that some of the issue is with the Interstate's electrical system (as suggested by previous blown fuses and possible fried parts).

So I said to heck with it. As a stopgap for short trips, I simply pack it with ice as if it were a twenty dollar Coleman cooler, albeit turned on its side.

And for longer trips, I plan to take several MSR Dromedary bags with us, just in case we face a recurrence. That way I can re-pack it daily with new cube ice from C-stores if I have to, without having the meltwater cause water leakage and penetration issues. MSR brand water bladders are very well-made - we used several over the years we spent backcountry camping, and none have ever leaked.

[73shark]

In defense of the current crop of problems w/ the late model refer problem, it seems that most are due to incorrect installation in that Airstream is allowing the correct amount of intake and exhaust for them.

[lewster]

As the saying goes........'you can put lipstick non a pig.......'

Sorry, but no matter what Dometic, Norcold or Atwood do to a gas/absorption fridge, it's still ancient technology!!!!

I'm replacing an ever increasing number of gas/absorption units with marine fridges using 12VDC powered Danfoss compressors.

Work 30 deg. off level and don't really care about the ambient temps. Get cold in a hour and STAY THAT WAY!!!


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[tlundell]

Originally Posted by Protagonist

A couple of 12v computer fans, one on the inlet and one on the outlet, should help. They're small and quiet and move a lot of air. You should be able to mount them in place of the existing vent openings with only a little bit of modification to the cabinet.


The 60 square inches you need are for natural airflow. With forced ventilation provided by fans, you can get more cubic feet per minute of air circulation through a smaller opening than you would get by the natural ventilation provided by "hot air rises" through a larger opening.

What would be the power connection for these fans?

[lewster]

Originally Posted by tlundell

What would be the power connection for these fans?

I use 92mm fans that have a stated draw of 0.2 amps @12V DC each. Attach them so that they are pulling the air, rather than pushing it as this is more efficient and allows you to position them directly at a vent outlet, again for better efficiency.

[jdalrymple]

[QUOTE=lewster;1692970]As the saying goes........'you can put lipstick non a pig.......'

Sorry, but no matter what Dometic, Norcold or Atwood do to a gas/absorption fridge, it's still ancient technology!!!!

/QUOTE]

Not to be too much a wiseacre, but mechanically compressed refrigerant systems ain't exactly a new idea, either.


Regards,

JD

[InterBlog]

Originally Posted by lewster

As the saying goes........'you can put lipstick non a pig.......'

Sorry, but no matter what Dometic, Norcold or Atwood do to a gas/absorption fridge, it's still ancient technology!!!!

I'm replacing an ever increasing number of gas/absorption units with marine fridges using 12VDC powered Danfoss compressors.

Work 30 deg. off level and don't really care about the ambient temps. Get cold in a hour and STAY THAT WAY!!!


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

Any particular brands that you recommend in the 4 cu ft range? West Marine carries Isotherm but it essentially has no freezer. Which means I'd still be carrying ice packs even if the fridge worked, because I need at least the size of freezer of the old Dometic gas fridges, if not larger.

[Protagonist]

Originally Posted by InterBlog

Any particular brands that you recommend in the 4 cu ft range? West Marine carries Isotherm but it essentially has no freezer. Which means I'd still be carrying ice packs even if the fridge worked, because I need at least the size of freezer of the old Dometic gas fridges, if not larger.

Nova Kool makes a 3.0cf unit that is used in the Airstream Interstates, a 3.5cf unit, and a 4.3cf unit.
Nova Kool, refrigerators, freezers, Marine, RV, Truck

[KJRitchie]

Originally Posted by lewster

As the saying goes........'you can put lipstick non a pig.......'

Sorry, but no matter what Dometic, Norcold or Atwood do to a gas/absorption fridge, it's still ancient technology!!!!

I'm replacing an ever increasing number of gas/absorption units with marine fridges using 12VDC powered Danfoss compressors.

Work 30 deg. off level and don't really care about the ambient temps. Get cold in a hour and STAY THAT WAY!!!


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

Have you ever installed one of these larger versions in an Airstream trailer?

Cruise 195 : Isotherm Parts, Marine Refrigeration Parts

Kelvin

[lewster]

Originally Posted by KJRitchie

Have you ever installed one of these larger versions in an Airstream trailer?

Cruise 195 : Isotherm Parts, Marine Refrigeration Parts

Kelvin

Several times. Also look at VitriFrigo. Both are made in Italy, and I use them interchangeably.....which ever one fits best for the application.

'Not to be too much a wiseacre, but mechanically compressed refrigerant systems ain't exactly a new idea, either.'

Not necessarily cutting edge technology, but one that works consistently well!!

No, but you don't hear many folks complaining about marine grade compressor fridges not holding temperatures when it's very hot out.