chametzoo
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Post by chametzoo on Jun 30, 2014 13:21:32 GMT -8
Hi all. I've got an Astral fridge, probably from the late 60's, early 70's. I tested it a few weeks ago and the pilot lit and it got cold. Recently fired it up again but it cools poorly in the current hot weather. Last night it cooled down to a bit below 50, but as the day has gone on it's now back up in the 60's, even with some cold mass inside of it to help it along. It's not showing any of the symptoms like gurgling or ammonia smell, etc. It's been lit for about 30 hours, so I'm losing faith that it will be able to cool enough in the summer temps.
With that said… any suggestions as to a replacement? I've looked at the small Norcolds with the Danfoss compressors. The compressors are extremely efficient on 12v and cool well at high ambient temps. But this would require an upgrading of the 12V capability of my rig. Right now it's just a single 12V deep cycle and no regulator. I've been considering 2X 6V's and a regulator to keep them as charged as possible. Would this be a satisfactory solution when off grid camping? I've never been crazy about the idea of running a fridge off propane, despite the benefits. Or… should I be looking at a standard 3 way? The Astral also runs on 110, but that part seems to be disabled. Thanks.
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Post by vikx on Jun 30, 2014 22:17:09 GMT -8
I would invest in a 2 way fridge. The 12 volt side isn't usually very efficient. Off grid, a propane fridge will go 2 or 3 weeks, depending on your propane tank size. Recently installed a Norcold 300N in a 67 Land Commander and the people can't say enough good about it.
Skip the batteries and go with Propane.
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chametzoo
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Post by chametzoo on Jul 1, 2014 7:01:42 GMT -8
I would invest in a 2 way fridge. The 12 volt side isn't usually very efficient. Off grid, a propane fridge will go 2 or 3 weeks, depending on your propane tank size. Recently installed a Norcold 300N in a 67 Land Commander and the people can't say enough good about it. Skip the batteries and go with Propane. By "2-way" you mean LP/110V? I agree with you now; the 12 volt (even with the 5 amp Danfoss compressors) is a fantasy and more suited to big rigs with lots of battery power. So propane it is. Do you have any preference for the Norcold over the equivalent Dometic [RM 2354]. Is there a good on line dealer to buy these from? By the way, the Astral, overnight got down below 50 degrees. Still not quite there yet. We'll see where it goes as the ambient temps heat up today and I'll let it cycle a couple of more days. It hasn't been used in a real long time. I checked with my local trailer shop and it was suggested that I check if the back of the unit was ventilated well. There is both a vented access door on the exterior and a stack that ventilates the space where the heat is produced… all the way up through the roof. I can also see that it's not blocked. Maybe a fan would help move the heat out of that space during hot days, but that would start to eat up the 12V… maybe a solar powered fan? |
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Post by vikx on Jul 1, 2014 11:06:15 GMT -8
The Norcold 330n doesn't require 12 volts to run. The equivalent Dometic needs 12 volts for the circuit board. (won't work without 12 volts, so if the battery dies, no fridge) That's why we went with the Norcold. Dometic does make a larger manual fridge but it usually won't fit in our little trailers, especially thru the doorway. LOL.
Sounds like the Astral is dying. There are a couple of things you can try and one is the fan. Try to find a solar fan to keep from using battery power... Also, you can "burp" the fridge. It involves removing it, turning upside down for 24 hours, then back upright for 12, re-install and see if it helped. I've had ONE burped fridge recover this way out of over 20... Not really worth the effort, because it might give you 6 months at best.
Norcold makes a tiny and very, very spendy AC/DC unit that's supposed to be pretty efficient. ($600??) Again, why worry about battery power?
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chametzoo
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Post by chametzoo on Jul 1, 2014 12:29:41 GMT -8
The Norcold 330n doesn't require 12 volts to run. The equivalent Dometic needs 12 volts for the circuit board. (won't work without 12 volts, so if the battery dies, no fridge) That's why we went with the Norcold. Dometic does make a larger manual fridge but it usually won't fit in our little trailers, especially thru the doorway. LOL. Sounds like the Astral is dying. There are a couple of things you can try and one is the fan. Try to find a solar fan to keep from using battery power... Also, you can "burp" the fridge. It involves removing it, turning upside down for 24 hours, then back upright for 12, re-install and see if it helped. I've had ONE burped fridge recover this way out of over 20... Not really worth the effort, because it might give you 6 months at best. Norcold makes a tiny and very, very spendy AC/DC unit that's supposed to be pretty efficient. ($600??) Again, why worry about battery power? I think you are right about the Astral winding down. But still, I'm not getting any ammonia leaks or gurgling as I often hear about as signs of a failing fridge. But it simply won't maintain temp… it is now 2:00 PM and the interior temperature is way up from this morning. Not reliable and I'm not sure a fan would help. The venting side of the trailer is in the shade all day, so I don't think it's excessive heat build up. I also live at high altitude (7200') and my understanding is that gas absorption units are not as effective over 5500'… I suspect esp. when 40+ years old! Thanks for pointing out that the Dometic needs 12v all the time to run the electronics… I didn't realize that. Also that seemingly minor but very important point about what will fit through the door is well taken! The Norcold literature shows that the enclosure cut out width is 20-1/2" and my doorway is 1/4" more than that! The body is probably somewhat less than the 20-1/2", but the surface mounting flange may exceed my doorway. I think these units are stocked at Central Trailer in Albuquerque, so I can ask them to give me a real world measurement. Vikx… if yours is handy maybe you could help me with that. Also, is there a good dealer to order from? |
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ladywendolyn
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Post by ladywendolyn on Jul 1, 2014 14:19:22 GMT -8
There is a German marine fridge that we have been looking at. They are sold here in Canada and are very low draw on the battery. My parents run it on their yacht and they insist that one deep cell battery can easily power it, (that's what they use) although we are planning on having two batteries. We have temps of 85-100 degrees all summer here, they have no air conditioning in their boat and they are in their fourth year with it, so we are going to give it some serious consideration. As I have started researching it, I have found out that this particular fridge is being used a lot in the van conversion, VW restoration world and they swear by it. One reason I like it, is that it doesn't have the "modern" look of the new rv fridges.. Although I am beginning to think that we should all write a petition to dometec and ask them to design a vinatge line. I will report a bit more on my experience with the German fridge. One thing we will look into is weather my husband can get it at a lower price as an auto dealer. Here is the link.. Just FYI .. Nova Kool Refrigerators |
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chametzoo
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Post by chametzoo on Jul 1, 2014 17:07:50 GMT -8
Here is the link.. Just FYI .. Nova Kool Refrigerators Thanks LW… I've looked at these in the past for other reasons. The compressors are VERY efficient; that's why I was interested in them. The small ones draw only 2.2 amps. Pretty amazing. They use Danfoss compressors like some of the Norcold's I mentioned do. If you could dedicate one deep cycle battery to it, it might work great for you. I'd still consider it as an alternative to LP. But they are a bit "spendy" as Vicx points out. But no more than a 2 or 3 way Norcold or Dometic. |
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Post by vikx on Jul 1, 2014 21:18:34 GMT -8
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chametzoo
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Post by chametzoo on Jul 2, 2014 11:18:14 GMT -8
Thanks Vickx & LW!… I'm considering my choices. BTW: we're having a lovely and mild day here in northern New Mexico and the Astral is staying below 40 degrees so far today. Maybe it does just need some extra and more active air circulation behind it for those extra hot days. Hmmm.
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yas
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Post by yas on Jul 2, 2014 14:17:22 GMT -8
It is a lovely day here today. Sure wish it would rain :-)
The air in Santa Fe is about 30% less dense than air at sea level. Hence it's ability to carry heat is reduced a similar amount. A small fan (like a 12v boxer fan) will move more air past the coils and should help the frig to work better. Many Norcolds in VW Eurovan campers have little fans that blow across the coils.
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ladywendolyn
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Post by ladywendolyn on Jul 2, 2014 19:16:36 GMT -8
Have you insulated around the space it sits in? Also ventilated?..
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chametzoo
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Post by chametzoo on Jul 2, 2014 19:19:21 GMT -8
It is a lovely day here today. Sure wish it would rain :-) The air in Santa Fe is about 30% less dense than air at sea level. Hence it's ability to carry heat is reduced a similar amount. A small fan (like a 12v boxer fan) will move more air past the coils and should help the frig to work better. Many Norcolds in VW Eurovan campers have little fans that blow across the coils. Yas… As I write this this evening, the rain has indeed come! You are right about altitude and gas absorption refrigerators. Even Norcold's manuals advise of inefficiency above 5500'. Today in the milder weather the fridge interior got down below 40, before peaking again in the afternoon at about 55. Tomorrow I will open the access panel on the trailer exterior and poise a fan toward the coils to see if that improves performance. Also, insulating the outside of the box on 4 sides should help maintain the interior temps all things being equal. That I'll try next and will require pulling the unit out. Maybe these efforts will help the Astral perform better under these extenuating circumstances of heat and altitude. It's already proven that with moderate ambient temps. it can really cool the fridge interior down to good working cold temps. So, I'm not done with it yet! |
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Post by chametzoo on Jul 2, 2014 19:32:03 GMT -8
Have you insulated around the space it sits in? Also ventilated?.. Hi LW… I've addressed the insulation issue in the post above. Not done yet, since it requires a bit of my time to disconnect and pull the unit out. So I now have a several days performance track record under pretty severe conditions. It does great overnight when things cool off here dramatically. I'll try more air movement first with a makeshift fan set up and see how it compares to previous days without circulation aid. If that helps, that will be encouraging and I'll move on to the insulation issue. As it stands, the back of the unit has a generous (maybe 12") space before it encounters the trailer exterior wall, where there is a standard vented hatch. Above the counter height, is a 3"X8" stack that goes to daylight out the roof. So it appears to be vented low and high as it should. But I think at 7200' and 90 degree afternoons we've had before today, as Yas advises, it needs more help if I expect it to perform. The insulation I see commonly used is the rigid board type… 2" all around if possible. Some folks even adhere a dense carpet remnant on the front door panel. The door gasket also appears to be in very good shape, so no issue there. |
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ladywendolyn
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Post by ladywendolyn on Jul 3, 2014 7:44:11 GMT -8
I saw a chart some where, that showed a study done on rv fridges with or without insulation and the results were quite dramatic, so things can only get better. If you can save yourself $1000 on a new fridge... thats awesome!
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chametzoo
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Post by chametzoo on Jul 3, 2014 8:53:27 GMT -8
I saw a chart some where, that showed a study done on rv fridges with or without insulation and the results were quite dramatic, so things can only get better. If you can save yourself $1000 on a new fridge... thats awesome! Yes, that would be awesome. This morning the internal temp was about 35F! I've got a fan on it today so I'll see if it maintains reasonable temp as the day heats up. If that helps I think it would be worth pulling it out and insulating.. Then would come a permanent fan installation. Anyone know of a semi-small solar powered fan unit? I've read accounts that even with the 2-4 amp efficient Danfoss compressors, insulating with rigid foam can cut power consumption by half. |
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