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landyacht318
Nomad
Posts: 247
Registered: 7-28-2007
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I think the insulation I added to my VF was isocyanurate not styrofoam. Whatever it is, It was 15$ for a 4'x8'x3/4" sheet at Home Depot. I was not
aware of the Glacier bay insulation, but a sheet of that appears to be ridiculously priced but is the type of overkill I usually research and then
place in the ideal but unrealistic column.
Most of these 1.8 cubic foot Danfoss powered fridges seem to use the same plastic molds as they all look the same, especially the interiors of the
doors. I am not sure they all use the same type/thickness of insulation. Mine was about 1.25 inches all around from the factory and I basically
doubled that, not including the 3/4 and 1/2" plywood that surrounds the extra insulation. To the exterior of that plywood I added some roofing
flashing with the reflective face, and the nearest exterior wall of the van body also is insulated in the area of the fridge. So sunny side/shady
side really makes no difference to the performance.
I have seen pics of a 2.2 cubic foot Tundra, and that used a 92mm fan in the 40 CFM range and covering only a portion of the condenser. It also
appeared to just have crimped refrigerant lines instead of a valve with a cap for refilling like my VF.
The NovaKool ( Canadian assembled)fridges appear to use passive condensers, which are larger, and have no fan but are Danfoss powered.
Isotherm seems to have attached a couple hundred dollars in price without much difference in construction, except for the ASU models which have an
additional cold plate which gets frozen by ramped up compressor speeds whenever battery charging voltages are sensed.
TruckFridge is the least expensive (Chinese assembled) of the front loading Danfoss powered Fridges and marketed toward the 18 wheeler types.
The Vitrifrigo impressed me with the larger 120 MM, 71 CFM fan and the condenser which seems sized to accept these and is attached to it with
Stainless Steel screws. The 92 mm fans on the other fridges apparently use Zip ties to hold the fan to the condenser and cover a smaller portion of
it. The 71 CFM fan was pretty loud though. I replaced it with a 54 CFM fan that has a higher static pressure rating, for much less noise and current
consumed. When I Switched fans, I also made a cooling unit tunnel to funnel the air and protect the coolant lines from installation removal stresses,
but noted that performance increased even with a fan rated at lower CFM's by timing duty cycles and taking interior and ambient temperatures before
and after.
I do have enough room to make a 3/4 inch thick insulated removable door cap which would seal tightly around the door for overnight or in between
meals/ beer swilling bouts, but again, overkill. Especially If I do not have WiFi, as my laptop is by far the biggest consumer of battery power.
I am guilty of contributing to thread drift. To the OP, a MSW inverter hooked to you battery, powering a blender is no biggie. If you are worried
about the battery, just run the engine when mixing beverages so as not to deplete the battery.
To anyone else interested in vehicular Solar and compressor refrigeration, I've got it down to science. Ask away. My limiting factors with my ride
when camping are food and water, not ice or battery power, though running out of the green bottles of propane for cooking have inconvenienced me in
the past.
But I do kind of miss the simple tent camping and cooking over a fire aspects of it all. Taking it all with me, kind of feels like there is more to
have taken away from me if something goes wrong.
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Hook
Elite Nomad
Posts: 9011
Registered: 3-13-2004
Location: Sonora
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Mood: Inquisitive
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The OP was long ago satisfied with the simple info he requested. I think we're OK here.
I dont miss simple tent camping; not being on the road for 10 weeks or so. 
There is one loss of cooling that I have always noticed with upright/front loaders. When you open the door, the movement of the door seems to draw a
significant amount of chilled air out of the interior. Then closing it forces a chunk of ambient air back in. I wonder if hanging some of those clear
plastic strips like restaurants use across the entrance to walk-in fridges would be practical?
Maybe it's not a significant amount, really, but I certainly feel the cool air out there. I guess a really sensitive digital temp gauge could tell if
it was a significant amount.
On my Norcold, why does the sound of it running seem to change from cycle to cycle? Should I open it up and investigate how the compressor is mounted?
Is it possible that it is coming loose from it's mount? Would rubber washers at the mounting screws help at all?
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willardguy
Elite Nomad
Posts: 6451
Registered: 9-19-2009
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I have been thinking about adding walk-in cooler curtains to my sunfrost for some time,it certainly couldnt hurt. im convinced the key to this
refrigeration debate is the integrity of the box insulation and the door gasket, along with simply not opening the darn thing. our refrigeration holds
probably 90% beer/10% food and ive always thought the trick would be to have a dispenser build in (like a coke machine) so you weren't constantly
opening and closing the door, I could never figure out how to do it in a chest freezer conversion with the evaporator coils in the way.
anyway back to the portables if you ever spot one of the coleman sterling free piston units at a segundo or yard sale, buy it. these were sold by
coleman till 07 and could be had for as little as 200 bucks when coleman was discontinuing them. sailors love em, you can still buy em from twinbird
for $$$$$
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ncampion
Super Nomad
Posts: 1238
Registered: 4-15-2006
Location: Loreto
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Mood: Retired and Loving it
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Although I too hate the thought of all that "cold air" rushing out of my fridg/freezer every time I open the door, if you look at the physics, it
really is not too big a deal. At STP (stand temperature and pressure) air weighs 0.0807 lbs. per Cu. Ft. So if your little 2 cu. ft. refer spills
out it's entire contents of air, it only represents 0.16 pounds of air. That assumes that there is nothing in the refer and everything is air. In
reality I'm sure at least half of the volume is taken up by food etc, so only about 0.08 lbs or 1.28 oz. of cold air is lost. It will take very few
BTU's to recover that amount of heat.
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willardguy
Elite Nomad
Posts: 6451
Registered: 9-19-2009
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good point, assuming you're not in and out every 15 minutes grabbing another can of beer! 
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landyacht318
Nomad
Posts: 247
Registered: 7-28-2007
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| Quote: | Originally posted by Hook
On my Norcold, why does the sound of it running seem to change from cycle to cycle? Should I open it up and investigate how the compressor is mounted?
Is it possible that it is coming loose from it's mount? Would rubber washers at the mounting screws help at all? |
This drove me absolutely nuts with my Norcold.
While the vibrations of the compressor itself could cause some things on the adjoining cabinet to vibrate and cause different noises, I found that
for no particular reason that the compressor itself would develop weird harmonics and the noise would be different from cycle to cycle.
I Did remove the compressor/ condenser assembly from the fridge box, and suspend it with thick silicone rubber washers, and this was one of the most
effective methods of vibration suppression I employed, but its effectiveness seemed to dissipate with time. The silicone rubber feet seemed to just
then add to the harmonics instead of dampen them after a time.
I used to get so peeed off at the noisy Norcold I would punch the fridge door, and this would then knock off the weird harmonics and change the noise.
Sometimes it would return during that cycle, and other times not. The amount and weight of the items placed within would affect the harmonics.
Usually heavier was better.
When it failed, going back to a cooler and block ice truly sucked, and I took some time researching new fridges before purchase, but when I first
fired up the Vitrifrigo, I had to put my hand on the compressor itself to see whether it was running. I wasn't happy spending another 600$ on a new
fridge, but the much lessened noise and vibration was worth it. Ultimately, I have found the Danfoss powered Vitrifrigo to be slightly more
efficient, and the Norcold too had extra insulation added, as well as a small fan to force air over the passive condenser for increased efficiency,
and the same interior fan.
You can go nuts trying to lessen the noise of the Sawafuji powered Norcold. A layer or 2 of damplifier pro or similar self adhesive noise supressor
in the cabinet in the area of the compressor is about all you can do with a larger fridge. I had mine floating on foam. The shelf it was resting on
was padded and resting on rubber cleats with layers of different thickness and hardness of material. The vertical flanges were also padded and
isolated from the cabinet itself. I was able to grab the fridge and it would be able to move 3/8 inch in any direction within the cabinet, and still
the noise and vibrations, if on the edge of sleep, would knock me out of that delicate threshold, and continuous white noise sources like fans were
required for a good night's sleep in a quiet environment.
When I first installed the New Norcold in the cabinet I specially built to house it, I employed no vibration suppression. It was resting on plywood
and the flanges were screwed tight into wooden cleats. I could tell from 15 feet away from the Van whether the compressor was running or not, and
touching the van body confirmed it. Laying on a 5 inch thick foam mattress, I could still feel the vibrations, even after I had the dang thing
mounted in a foam cushion in the cabinet.
I have little doubt that the vibrations and my attempts to reduce them stressed the hollow refrigerant tubing and contributed to the slow loss of
refrigerant which caused the fridge to fail. But basically after 5 years of near continuous operation, various forums said congratulations, time for a
new fridge, and I bit the bullett.
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bajamedic
Nomad
Posts: 392
Registered: 12-5-2008
Location: Northern California
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Mood: Just waitin for baja
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This is a portable solar system that I used in the communications portion of my job (yes, I did work in my past life). The basic system comes as a 60
watt, but is eaisly expanded to 120 watts, all in a neat little case. It is a little spendy, but you get what you pay for. JH
http://www.danelec.com/pdfs/MKT%20118%202010%20Transportable...
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Alm
Ultra Nomad
Posts: 2753
Registered: 5-10-2011
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Yes, Novakool have passive condensers spanning the width of the back. I don't think this in itself is a bad thing. In a van it's more difficult to
arrange a proper ventilation without fan, but in a trailer passive condenser will do. Most heat is generated by compressor, not condenser. Novakool
has (optional?) fan for compressor cooling, and it's attached with screws few inches from the compressor, no zip-ties. Some people added condenser fan
to Dometic - which already has a fan, but as Landyacht noted, it's mostly for compressor cooling.
Isotherm is priced higher, though not much higher. Their "Cruise" line comes in different versions - with or without freezer tray, regular box or
stainless, with ASU or without. 1.7 or 2.3 cu.ft box, regular, no ASU unit, Isotherm costs about $100 more than Novakool or Dometic (aka Coolmatic),
and sometimes cost is the same. Westmarine carries Isotherm and Dometic. Larger 5+ cu.ft boxes are designed differently in every brand - compressor
can be at the bottom or at the top, and when it's at the top, the compressor/condenser bundle can take a corner or the entire width of the back.
PS:
With upright Vs top-loader - the physics says that top-loader should be more economic because the cold air is heavier so it doesn't "spill" when you
open the top lid. In practice this seems to work for large boxes only - like 5 cf and larger, and when the temperature difference is substantial -
like a standalone top-loader freezer. Small 2 cf top-loader, given the same insulation, won't be much different from front-loader if you open it
often. Portable top-loaders are not in the same league here, - they have less insulation and airflow around compressor/condenser bundle is not
optimized.
[Edited on 12-30-2012 by Alm]
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willardguy
Elite Nomad
Posts: 6451
Registered: 9-19-2009
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also, haven't got any feedback on the sterling free piston engine portable units. they are amazing!
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