3 way fridge install & sealing to wall

marklg

Well-known member
I've spent most of the last week 'researching' (surfing internet and quizzing friends) on rv fridges, both compressor and absorption, and am only marginally better than when I started. For almost anywhere on the west side of USA I would not hesitate to get a compressor style. Solar ability, reliability, and ease of install make the decision. But this rig is being built to travel Northern Canada and we don't get the 'high in the sky' sun best for solar. Between the lower sun, clouds and treed mountains I would need a generator to recharge the batteries and I don't have, nor want, one. Van would almost never be in a place to plug in to shore power. If they hadn't made the change so that a propane fridge now needs 12v to run on propane (WTF? unlike all the ones I previously had) there wouldn't have been any decision to make. I thought if I needed to supply 0.9 Amp/hr for propane and a compressor would only draw twice that then go with the compressor but if I can't replenish the battery then my stay is halved. I just added LiFeO4 battery and 100W solar to my truck camper for just this reason. The original fridge died and was replaced by a new one that drained the battery to the point of ruining it in short order. Guess a long Northern trip is in the plans and then I'll have some real world data on where I go.
Hippy- I don't quite understand about the z shape; is it just sheet metal with a bend to ease install?
Pic shows where I planned on installing the vents needed for absorption fridge. Horizontal structures above and below bottom vent are the issue.
View attachment 229614
All 3 way Propane fridges I know of needed 12V for the controls and to light the burner. I don't know how much energy they use. I do understand if you boondock and have no sun, it may be your only solution, however, you may then have problems with lights and small appliances. We have the new fancy batteries, solar and a compressor fridge, but once in a while we still have to run the old generator. We camped in October in a location where mountains kept the sun from hitting the van, so minimal solar. I get it may not be a choice for everyone. If everyone did the same thing and went the same places it would be boring and crowded. Just try to figure out by the numbers what you need so you are not disappointed.

A Propane detector, a Smoke Detector, A Carbon Monoxide Detector and a fire extinguisher are absolute musts if you have Propane and Electrical Installations. We have two CO detectors, the newest has a display to see levels lower than make it go off. I also have a portable combustible gas detector for Propane leaks. It will often also go off on exhaust gasses.

Regards,

Mark
 

maint

Member
5 degrees in a Sprinter is 5.5 inches out side to side or almost 14 inches front to back. Just for comfort inside I would never park it on that angle. As for overnight I level it to an inch or so for sleeping.
'Run on sunshine' requires sunshine though; propane can be bottled. The previous Dometic 3 way fridge I bought new was 12 years ago and I never ran wires to it. Didn't need them unless running 12v heater unit and that would kill my battery. They used a thermocouple to open the gas flow, no control board. With one small SLA battery I have stayed for weeks in the bush using only a light at night over the table. Unfortunately the new absorption fridge I bought last year (with "minimal 12v draw") killed the battery in 2 nights running the board.
Detectors are so cheap it would be crazy not to have them. The 2008 Okanagan class B I had had a crack in the plastic near the water heater that set off the alarms in certain winds until I figured it out and replaced the piece. One of many faults with it.
 
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Nic7320

Solera 24S on a 2011 NCV3 chassis
I'd like to think that is true, but clearly there was a CO leak into the cabin. This Dometic fridge was in a Roadtrek circa 1997.

Also an item I should have been wary of, was the long note from the previous owner about how to reset the CO detector. It was also well past its ten year lifespan.
 
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wankel7

Active member
I'm confused - you want to build out a winter worthy rig yet you're going to cut two large holes in your van for a propane fridge? These fridges don't like subzero cooling air - they rely on adequate heat to keep the absorption process going.

How are you going to level your rig when there is snow and ice on the ground? It's a total pain. Even without snow and ice - nothing like grinding out a long drive and at the end of the day the rig isn't level. With the absorption fridge instead of just walking into the back and start drinking and making dinner....you need to get out and level things. No fun. Need to leave in a hurry....guess you're leaving your leveling blocks behind.

We had a 3way in our trailer and I was super careful to level it. Cooling unit plugged anyways. Best day with piece of junk was when it hit the bottom of an empty dumpster. So satisfying.

I would do everything you can to beef up your house electric. Mainly with good alternator charging.

I can't believe anyone would voluntarily put a 3 way in a van build.
 

maint

Member
Nothing was said about going in snow or ice. if there is snow on a hunting trip we put everything in a cooler and throw it outside, free cooling. But it's never been too cold for the fridge to work. Also worked fine above Telluride at 8800 feet
Alternator charging only works if your motor is running; may as well get a generator.
Only time I ever had to leave in a hurry was NOT in Canada but if I leave a 2x6 behind it would be OK. What would not be OK was having to leave where I am camped after 4 days because the batteries run down.
The original question was about how to seal a propane vent. The two vent holes are sealed, separated from the inside and fully insulated so a Non issue. If it becomes almost impossible to do I MAY go compressor but, up North, solar alone is not enough to maintain batteries for a week or more in one spot. If someone from Alaska wants to jump in and tell me how they manage to boondock for weeks using a compressor fridge on solar I may re-think it.
 

Kajtek1

2015 3500 X long limo RV
There is "solar paranoia" lately, that I observe on the forum.
I do have only single 120W solar panel on my Sprinter, when my refrigerator takes 280W to run.
That is ok when I travel and do up to 4 hr stops, but if I stay overnight with no power, I either turn the fridge off, what will keep it relatively cold overnight, or some time ago Home Depot was selling 1000W, inverter generators for $150.
It weight 20lb, is the size of lunch box , while running most of the day on 2 cups of gas.
The tank has good cap, so even when I keep it inside, I don't smell gas. For extra fuel I kept 1 of those 1 gallons glass wine bottle and observing less than 90% of fill in it, I can last several days with no outside power and single 60 ah house battery.
The fridge originally had propane burner, but I deleted that option as creating too much danger and too much hassle.
 

Nic7320

Solera 24S on a 2011 NCV3 chassis
The solar issue in the PNW is a real problem. You can go a week or more with rainy and overcast skies. Also, many campsites here are under a full canopy of tall trees.

So you either need 2X or 3X more panels which is impractical, or a B to B charger, or a generator, or you have to camp somewhere with shore power. Most campgrounds here provide power and charge accordingly, but I don't need it -- most of the time.

Before getting solar and more batteries, I bought two small gas generators. One was the Sportsman brand from Home Depot. The other was a 2kW inverter generator from Generac. But after I got solar, i didn't use them enough, and they both failed when I tried them a year or so later. Unless you empty the fuel and thoroughly clean the carburetor after each use, they can gum up and won't start. So I keep an RN60 resistor hanging on the carburetor to clean out the orifice of the Generac.

The Sportsman has a governor problem probably due to corrosion. It starts, over-revs, and shuts down. It fit nicely in a NEMA box on the spare tire rack, but moisture still got in there and condensed in the box.

Propane generators seem like a better option for RVs since it doesn't turn to varnish. But that's 200 extra pounds to carry. And then there's the noise issue. Boondocking in popular areas means respecting your neighbor's desire for peace and quiet. My 3 kW propane generator probably bothers me as much as any neighbors, so I don't use it.

So there's no simple solution to limited sunshine.
 
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marklg

Well-known member
The solar issue in the PNW is a real problem. You can go a week or more with rainy and overcast skies. Also, many campsites here are under a full canopy of tall trees.

So you either need 2X or 3X more panels which is impractical, or a B to B charger, or a generator, or you have to camp somewhere with shore power. Most campgrounds here provide power and charge accordingly, but I don't need it -- most of the time.

Before getting solar and more batteries, I bought two small gas generators. One was the Sportsman brand from Home Depot. The other was a 2kW inverter generator from Generac. But after I got solar, i didn't use them enough, and they both failed when I tried them a year or so later. Unless you empty the fuel and thoroughly clean the carburetor after each use, they can gum up and won't start. So I keep an RN60 resistor hanging on the carburetor to clean out the orifice of the Generac.

The Sportsman has a governor problem probably due to corrosion. It starts, over-revs, and shuts down. It fit nicely in a NEMA box on the spare tire rack, but moisture still got in there and condensed in the box.

Propane generators seem like a better option for RVs since it doesn't turn to varnish. But that's 200 extra pounds to carry. And then there's the noise issue. Boondocking in popular areas means respecting your neighbor's desire for peace and quiet. My 3 kW propane generator probably bothers me as much as any neighbors, so I don't use it.

So there's no simple solution to limited sunshine.
There are quiet Diesel generators, but they are expensive. Onan now sells Inverter Propane generators that are supposed to be quiet, also expensive.

There is plenty of forest service land you can camp on in AZ with clearings for your solar panels.

Regards,

Mark
 

Nic7320

Solera 24S on a 2011 NCV3 chassis
I'll be there come winter. A few dozen stops along the Sierras on the way. Then RTR and Mexico in January.

I probably won't bring the solar trailer since there's no need in SoCal and Az. I ditched it recently and put it in storage because it was such a PITA to tow. Twice I had situations that almost required disconnecting it to complete a turn. One culdesac in Astoria was so tiny I barely made the turn, but had to move a dumpster in the way first. And this was on a crazy steep hill, and the only thing keeping the dumpster in place was two rubber chocks... and then me, barely negotiating it to the other side of the street. The trailer is useful for tools and some workshop space, and I wanted to put e-bikes in it, but that will have to wait. It also destroyed the ride of my RV and probably the shocks and struts, bucking up and down as much as it did. The axle is a bit too far forward, but moving it requires cutting metal to move the fenders, so I might just add a longer tongue.

And now, back on topic: If the Roadtrek's propane fridge combustion chamber is *supposed* to be sealed from the controls on the bottom, then there's a problem. It seemed to share the same ventilation space, but also there was a pretty stiff wind bearing down on that side of the van, so any pathway could have been a problem. I have to look into it. Removing the fridge to replace a knob shaft coupler took a lot of determination and effort, because it looked like someone had added additional adhesive to stop some vibration and rattles, unrelated to sealing the chamber. Or maybe that was just the way they do it. In any case, a serious look at the ventilation space is in order if I use it again.

I originally bought the Whynter compressor fridge chest for that vehicle, because it fit between the front seats. It's nice to have a cold beverages at the ready when driving, but I do keep it locked if there's open alcohol in it (quite infrequent, but it happens). The same fridge fits nicely in the Sprinter after I removed the passenger armrest.

How do I prove to an LEO that the fridge key is inaccessible when I'm driving without an extensive vehicle search? How do I prove I didn't just throw it out the window? This could be a problem. I don't know how the "housecar' alcohol exemption works in all states, so with an open bottle, I have to be cautious. This is a topic for a different thread.
 
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Nic7320

Solera 24S on a 2011 NCV3 chassis
Dometic install says clearance at the back must be 0 to1/4" (This is to force the air to flow up through the cooling coils).
It sounds like the limited slot depth is necessary for passive cooling, as you say, to allow convection currents to develop enough air velocity past the coils. But if you add active cooling with cooling fans, you should have more options how to design the cavity to provide the necessary flow of air. It would be good to do this with guidance from the manufacturer. Perhaps a call to their technical support can give you what constraints to follow, such as "keep cooling fins below xxx degrees (under a specific set of test conditions)" or "you must have xx lineal feet per minute of airflow" and then you'll have a specific target to hit.
 
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Cheyenne

UK 2004 T1N 313CDi
I'm confused - you want to build out a winter worthy rig yet you're going to cut two large holes in your van for a propane fridge? These fridges don't like subzero cooling air - they rely on adequate heat to keep the absorption process going.
If you are going to use an absorption 3 way fridge in ambient temperatures below approx 8 - 10 °C then you have to fit vent covers which restrict the airflow over the fridge and allow it to work correctly.
1660727661480.png
 

hippy

Hardware Modifier
If you are going to use an absorption 3 way fridge in ambient temperatures below approx 8 - 10 °C then you have to fit vent covers which restrict the airflow over the fridge and allow it to work correctly.
View attachment 229683
Exactly this, I have a matching black set, as soon as it's maybe down to 5c and all over the winter period.
 

wankel7

Active member
If you are going to use an absorption 3 way fridge in ambient temperatures below approx 8 - 10 °C then you have to fit vent covers which restrict the airflow over the fridge and allow it to work correctly.
View attachment 229683
Maybe it's the -4F morning in Oregon that helped kill off our fridge and plug the cooling unit.

Too many accomodations for these things...cold weather is a problem, hot weather is a problem, ventilation, needs too be level, open flame...
 

hippy

Hardware Modifier
That is because the seal should be around the rear of the fridge and the exhaust gases should never get anywhere near the control panel.
And exactly this, the gas and guts end of the fridge are only exposed to the outside world and are completely sealed from the habitation compartment. Completely airtight sealed with silaflex on all the joins and tested with my smoke machine.

There is a level attached to my ceiling and one attached to the dash so as I park I can shunt until I find a totally level ground not that in 3 years of camping off piste have I ever worried about it and it's never etc me down.
I can be -8c outside and my freezer still stays at -20c it has zero problems with heat or cold temperatures.

Last week it was 37c outside, the freezer was still -20c and my ice lollies and magnums never melted once
 

hippy

Hardware Modifier
If you fit it correctly it is the bees knees. If it's sunny then its free, if I'm driving it's free, if it's dark I run it on gas of which I'm maybe on my 3rd 7kg bottle in over 2 years.. that's cheap cooling.

edit it's about 12.5amps or so on 12v but I see 25amps for my solar most sunny days, less on really got days when I'm down to about 19amps if the panels get to hot.
Saw 27.7 amps while they were super cool from washing them.
image.jpeg
So the fridge drain is not really an issue.
If I'm plugged in and the battery goes down to 12v then a charger kicks in an gives it 40amps till its full
 
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wankel7

Active member
If you fit it correctly it is the bees knees. If it's sunny then its free, if I'm driving it's free, if it's dark I run it on gas of which I'm maybe on my 3rd 7kg bottle in over 2 years.. that's cheap cooling.

edit it's about 12.5amps or so on 12v but I see 25amps for my solar most sunny days, less on really got days when I'm down to about 19amps if the panels get to hot.
Saw 27.7 amps while they were super cool from washing them.
View attachment 229688
So the fridge drain is not really an issue.
If I'm plugged in and the battery goes down to 12v then a charger kicks in an gives it 40amps till its full
With that much of a house electric system a compressor fridge would have been easy peasy.

There is always a small fuel cost associated with alternator charging. Unless maybe you're coasting down hill and the fuel injectors aren't running.... I guess that's the camper version of regenerative braking:p
 

hippy

Hardware Modifier
With that much of a house electric system a compressor fridge would have been easy peasy.

There is always a small fuel cost associated with alternator charging. Unless maybe you're coasting down hill and the fuel injectors aren't running.... I guess that's the camper version of regenerative braking:p
Your correct Wankel, after running the battery down to about 12.2v after a heavy night of entertainment including movie projection with the accompanied big sound I notice on the way home I was taking 59amps from the alternator and that dropped my mpg from 23mpg to 21mpg for about 30 minutes. It slowly crept upto 23mpg a few hours later when I got home.

There were some monster hills and I was down to 4th a few times!
 

wankel7

Active member
Your correct Wankel, after running the battery down to about 12.2v after a heavy night of entertainment including movie projection with the accompanied big sound I notice on the way home I was taking 59amps from the alternator and that dropped my mpg from 23mpg to 21mpg for about 30 minutes. It slowly crept upto 23mpg a few hours later when I got home.

There were some monster hills and I was down to 4th a few times!
Wow that is a big bit..... difficult to quantify that alternator drag....cool you could see it.
 

maint

Member
Nic7320 you had a good suggestion. I contacted Dometic tech support and asked them. I described what I wanted to do (see drawing at beginning of thread) and why. He described it as a 'duct to clear structure' and, although the 3-4 inch length wasn't ideal, it would work. The box with ducts is the easiest way to seal the enclosure and maintain clearances.
*I had never heard of a cold weather kit (learned something there). My fridges have always worked in the cold BUT I don't use the Camper in very cold weather. Wall tent with a wood stove is much more comfortable at -15c. I was serious about just throwing a cooler (too keep stuff from freezing) outside.
*As to gas being able to sneak past at the controls- I replaced a 'light tube' on an older fridge and, now that I think on it, there wasn't a lot to seal the front of the controls from the back. The new one I bought was a floor model and someone had torn off the cardboard baffle from the top back edge of the fridge. I had to make a sheet metal one. It just helps to keep hot air from going down the gap at the top of the fridge. 'Helps' but not seals; Gases could get to the back of the controls. The new one is all electric with no mechanical bits going through and maybe this is part of the reason they switched from thermocouple to circuit board controls. The enclosures are sealed from the inside everywhere except the front of the fridge. The flanges on the front have a foam tape that supposedly seals the front. The 0-1/4" clearances around the fridge are to stop hot gas or air from pooling around the fridge.
 
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