110 Volt Fridge

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Blue~Go
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Re: 110 Volt Fridge

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Break out the ice cream! :D
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HoosierB
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Re: 110 Volt Fridge

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Somewhat related to this topic:
I have the Vitrifrigo C75 AC/DC with external compressor. I will be installing the fridge where the old stove location was (above the wheel well enclosure). Then locate the remote compressor unit on top of the generator enclosure box (originally the bottom platform for the old Dometic). BTW: I have removed the old carpeting and pad form the gen box and installed Dynamat. I am also retaining the "air chimney" for ventilation, using the outside access door for fresh air intake and the roof vent for exhaust.

My question, is there a way to improve the design of that access door which is so prone to leaking? After a rain, there is always a little puddle of water on top of the gen box. Roof vent is not leaking. Is the problem inherent with the 3 vents, the seal between the door frame and body or the door seal itself? Any remedy will still need an "air intake" in that location.
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Blue~Go
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Re: 110 Volt Fridge

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I've thought about that a fair bit myself. One issue is that where that vent is, the body of the Chinook slants slightly inward as it goes up -- just what you don't need! Also, as you point out, there is not only the actual vent holes for water to potentially get through, but also the gap around the removable section. (The interface between the flange/frame and the body can be properly sealed, but that still leaves the above two issues.)

There is one solution that I would strongly consider implementing if I could (but since I'm putting the refrigerator in the refrigerator hole, and I want the hallway to be as wide as possible, I can't do it this way): That is to use a flat panel to block off the large square hole in the body (I have done that), and then put one of a few possible boat vents into that panel. These vents are much more resistant to water ingress, and they tend to have an upward "schnozzle"/drain as part of the design. (This means you might want the compressor a bit further up, so that it won't be below the schnozzle, but I don't see any reason you couldn't do that.)

Some examples below. Once nice thing is that they always list the ventilation area, so if you are wanting to calculate (for example, I think the BD35 wants 25 square inches) you can do so. One thing that I'm not sure of though, is how one compares relatively passive area to intake area when you have a marked chimney effect. I would think the latter would require less intake area (in fact sometimes it's critical - my former woodstove worked perfectly with a 6" chimney; an 8" chimney would have *reduced* the draft and made it work less well).

Vetus ASV louvered vent and DBOX dorade box
Vetus ASV.png
Vetus DBOX.png
Vetus ERV
Vetus ERV.png
Continued in next reply...
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Blue~Go
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Re: 110 Volt Fridge

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Vetus TYPHOON or SCIRROCO
Vetus TYPHOON and SCIROCCO.png
*******

Since the planned placement of my refrigerator would make it impossible to have any sort of inner dorade or pipe where the current lower vent is (because the refrigerator will be right up against the outside wall, essentially), I have thought about either a different lower venting (intake) scheme, or.... do I really need/want exterior venting?

Taking the latter first, no, I don't need exterior venting. I have been running my "portable" CF-50 (same BD35 compressor, albeit smaller box) indoors for over two years now, and it runs just fine. Granted, if it's 95ºF in the living room, the compressor is adding unwelcome heat to my already warm living space. But on the other hand if it's 40ºF outside, it's.... adding welcome heat to my living space. So that may be a horse apiece. On the other hand, I can hear the compressor fan (it's very quiet, but still audible to me in very quiet ambient situations). If the venting were completely exterior, I'd be able to isolate the sound, I believe.

But is that worth having two big holes in the Chinook shell? And/or the complication and space of a chimney even if those holes are well conceived and sealed? Not so sure about that. If I were in hot climates exclusively, I'd say yes for sure. Or if the world were so quiet that hearing the refrigerator compressor fan was a constant annoyance (I WISH the world were that quiet). (But also, apparently the stock fan can easily be replaced by a quieter/better one, so I'll be doing that in any case.)

Still, I don't like to not do something just because I haven't bothered to think of a good way. And I guess thinking about these things is my version of "counting sheep," so....

The roof vent doesn't seem to be a leakage issue, in my experience. I've had a wooden cupboard just below it for over a year now, and have never seen any water come in. And that includes some nasty monsoon storms in early AZ summer. And that vent is not in my way at all. So that leaves the lower intake, which is known to be problematic, and in my case I won't have space to ameliorate that. So, if I want to do an all exterior venting scheme, how to get the intake air? If I use the exterior chimney scheme, I'll likely place the compressor in the upper cabinet I have just under the roof vent.

1) Use only the roof vent, with a septum to divide it into intake and exhaust sections. Possibly augment with something like Vetus FAN12 (draws .19 amps) hooked up so that it comes on only when compressor runs (if necessary at all).

2) Use something like an ERV, TYPHOON, or SCIROCCO up higher on the body - maybe in the area of the "porch light" under the awning (which I never use).

3) Use a plywood box shape or a round plastic plumbing pipe and bring air in from under the coach, up the forward/rear corner of the closet and into the cupboard under the roof vent.

If I go with solely interior venting, I'll likely put the compressor on the floor under the stove area, in the pretty much perfectly sized flat area that is just aft of the wheel well. Then intake would be in the "kick space" there, and exhaust would be in a backsplash/vent above the stove counter surface. That would be an easier install, and I could re-use the roof vent flat for a Dometic stove exhaust if I wanted to.

Jury's still out. Luckily the CF-50 is happily keeping my food cold. Only downside is that it can be a freezer or a refrigerator, but not both. So I'm missing having a freezer.
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HoosierB
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Re: 110 Volt Fridge

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Blue~Go wrote: 1) Use only the roof vent, with a septum to divide it into intake and exhaust sections. Possibly augment with something like Vetus FAN12 (draws .19 amps) hooked up so that it comes on only when compressor runs (if necessary at all).
Blue-
If I were to install the external compressor unit in the location just below the OEM screened roof vent in some type of overhead cabinet as you described and block off the lower access door vents eliminating the "air chimney" effect, what type of "septum" design would allow intake and exhaust? Or does it matter in such a small space? Almost like having the compressor unit just sitting outside...???
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Blue~Go
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Re: 110 Volt Fridge

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Hi Hoosier,

This is so far, just an idea I had. I do now already have a cabinet just below the original roof vent (when I re-did my cabinets I made both main sides "three units" long -- so in other words the above-stove cabinet is part of the main long dining cabinet, just like on the couch side). So I have a separate little overhead cabinet that basically matches the other ones, but is its own unit between the stove/fridge wall and the fridge/closet wall (hope that makes sense).

That location, and/or the area behind the wheelwell and under the stove are my two contenders for compressor location.

But as mentioned above, I don't have an easy way to make a ventilation chimney, AND a watertight lower vent hole because my refrigerator is going to be fairly tight to the outside wall there.

So yeah, one of my thoughts was, well, this is NOT a "fireplace" like the absorption fridge was. No combustion is occurring, and no flames are burning. The stand-alone portable refrigerators (like the CF-50 I've been running the past 2.5 years) just have open holes on each side - one intake and one exhaust (and I calculated - they are almost exactly each the 25 sq. in. recommended by Danfoss).

So.... what if I ONLY used the roof vent? It's relatively huge (I have yet to calculate the open area though), doesn't seem admit water, and is right above one of my optional compressor locations. Two things though: One, is that it's important to separate the intake and exhaust air (so the intake can't suck in the "pre-heated" exhaust air), and two is that while the exhaust would have a natural heat-rising nature, the intake would be pulling air down -- maybe that would want assistance? I don't know. As I think about it, probably no big deal since the fan that comes on the compressor already does suck air in (vs. pushing it out at the back).

As far as a septum, I'd just use a piece of thin fiberglass board or something like that to make a vertical divider. I can't remember right now which end is which, but basically the compressor is shaped like a shoebox, and one short end is intake and the other short end exhaust. So a septum that ran east-west and divided the long, narrow roof vent into two squares is what I was thinking.

But all that said, I'm starting to think why not just use inside air for the whole shebang? No holes, no dust being sucked in on back roads (to the compressor), no nothing. Yes, it slightly adds heat to the rig in hot weather (although that would be even less with your smaller unit), but at least for me, I'm probably just as often camped in cooler weather where I'd welcome a little bit of heat (it's not much).

So then I'm back to the compressor next to the wheel well under the original stove area (which would be just under your fridge, so maybe you have no room for insulation?). Intake at the floor area, and easy to build a hood for that (to only allow "room" air into the intake, not any of the exhausted air), and then let the area behind the oven or drawers be the chimney, then make a little raised backsplash that has an outflow crack (1" x the 25" wide of the counter equals the 25 square inches). Reason for that is so the crack is not at counter level and letting crumbs or etc. fall down.

You may not want to do it there since you'd have the same issue as me in the fridge location - why sacrifice depth where the refrigerator is (which would be you in the stove location). But maybe in the next compartment?

So upshot is, although I can think of a number of clever ways to do the exterior chimney venting.... I'm not sure it's worth the trouble and holes, especially for a non-huge refrigerator (less heat in any case than a larger one). No way to prove that one way or another, just thinking out loud...
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Scott
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Re: 110 Volt Fridge

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I agree that you could get away with closing both absorption vents entirely and just cool the compressor with coach air. The amount of heat added to the coach would be basically equal to the heat removed from the fridge, plus the heat generated from the mechanicals and such. As we've learned from Paul in this thread, a functional cooling fan is most critical. Fortunately there are millions to choose from, they cost nearly nothing, they use very little power, you have pusher/puller mounting options, and a power source right there. Unrelated, I have plans to experiment with a little fan inside the fridge to help distribution; the wires for the fridge light should make it easy to hook up.

If I had a remote compressor (refrigerator envy), I'd mount it up above, source cooling air internally, and then implement a manually-operated baffled duct so exhaust can be directed out the roof vent or kept in the coach depending on weather/season/dust. The space behind the wheel well makes sense too, but I like that area to store heavy stuff like canned food (tuna and sardine addict) because it's low and isn't a flimsy shelf. I'd also mount it such that I could easily access the cooling fins so I could keep them clean.

Regarding dust, my upper fridge vent is as stock, and the lower is blanked off. I have a black fridge, and I'm on dirt roads all the time; yeah a little dust gets in, but it's a small percentage of the overall mess that enters just from regular use. Of course, that's all relative. I like it open for air circulation, but I'm going to blank off the upper vent this winter, but mostly just for warmth reasons. I don't expect I'll notice much difference though. Sorry if I'm butting in (since my residential fridge doesn't have an external compressor, the coils are in the walls, and there's no fan). Just wanted to share some thoughts/experience
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Blue~Go
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Re: 110 Volt Fridge

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Just as a data point, all of the refrigerators I've seen with the BD35 or BD50 compressor do already have a fan mounted on the compressor. This fan sucks air in to the "beginning" of the compressor works. One can also mount an additional fan, and there are two provided terminals on the compressor that make this second fan come on when the compressor does (and shut off when the compressor shuts off).

Scott: Hmm, your idea about using indoor intake and a variable indoor/outdoor exhaust is interesting. I had thought about using indoor intake and outdoor exhaust (since it's the outside intake that's slightly problematic), but for some reason the idea of combining the two seemed like it might not be good (like say it might cause some sort of "backflow" with other appliances such as heaters, or it might try to suck heat in from the doghouse when driving). I have no idea if the relatively "light" flow of a refrigerator compressor would actually do that, but I knew if I didn't have a "combined" vent then there would definitely be no issue.

But.... having an exhaust vent that could be changed around.... hmm, interesting.

And now you've re-kindled my desire to put the compressor up by the ceiling. It would intake warmer air there (vs. the cool floor) but maybe not that much warmer. OTOH, where it would be an annoying challenge, is in constructing the cabinet and getting it up there. Reason is that the copper line to the refrigerator box is not detachable, but of course who wants it dangling at the front of the cabinet. Of course it can be figured out.

I am getting REALLY tired of not having a freezer, so I think my days of having my Vitrifrigo in a box instead of in the Chinook are drawing to a close (really the whole thing hinges around the fact that the cabinets are (and kind of need to be) constructed in a way that makes it a LOT easier to install flooring with all those cabinets out of the rig. If only they could just have nice tidy kick panels like houses! (But that would be tough in places such as where the cabinet bases only get a wee "foot" as it is such as where they cross over the wheelwells.)
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Scott
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Re: 110 Volt Fridge

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I've seen Paul's, and I hope he doesn't mind me saying, but he has a very nice fridge. I saw how the fans mount, the compressor arrangement, condenser core, the power connections/options, the serviceable refrigerant charge port, and the capacity oh man :shock: . They really did a nice job.

For in/out, the volume of air being moved is pretty small in the grand scheme IMO, and very low pressure. And the pressures/flows and ins/outs in the coach while on the road are probably all over the place anyway. I can definitely respect your desire to prevent fumes entering the coach via the doghouse, but that baby should be sealed up really well, and I don't expect a little fan on the condenser core exhausting to the outside would influence flow at that location. Was just thinking that the space by the upper vent in my rig is basically wasted volume, so I'd mount the compressor there. Also convenient that it's already cut out so you have full choice for venting/cooling without altering the shell. Being able to control the discharge is just neat-o for when you're melting in the desert or freezing in the mountains. To come clean, part of these thoughts stem from the awesomeness of a remote compressor and the liberties gained from such an arrangement; you can do whatever you want, so may as well!
And now you've re-kindled my desire to put the compressor up by the ceiling. It would intake warmer air there (vs. the cool floor) but maybe not that much warmer.
No you're right, and that's a fair point. Just intuitively I doubt the slight difference in ambient air temp (up high versus down low) at the compressor would be significant enough to affect duty. As long as that little fan is moving air over the coils, I'll wager that 10 or so degrees probably isn't going to measurably impact your SOC at the end of a solar day. Ambient temp at the fridge itself would affect duty however. Plus every refrigerator that I've seen that doesn't have a remote compressor, has their compressor and condenser at the worst possible location; take the hottest components of the system and stick them underneath? I get it from a design/packaging standpoint, but it's silly thermal management. So you're already way ahead in that regard. My condenser coils are in the walls of the fridge :cry:, but hey the upside is they never get dusty!
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Re: 110 Volt Fridge

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Blue~Go wrote:And now you've re-kindled my desire to put the compressor up by the ceiling. It would intake warmer air there (vs. the cool floor) but maybe not that much warmer. OTOH, where it would be an annoying challenge, is in constructing the cabinet and getting it up there. Reason is that the copper line to the refrigerator box is not detachable, but of course who wants it dangling at the front of the cabinet. Of course it can be figured out.
Installing my new fridge in the old stove location necessitated a small "access hole" be cut in the lower portion of the original forward vertical fridge wall, which is now a somewhat modified reinforced septum/support wall in my remodel. This access allows just enough clearance to slide the remote compressor in and set on top of the gen-set box by the lower outside access door vents. A cover panel for the access hole will be screwed in place and have proper grommets for the supply lines. Service for the remote cooling unit is by way of the OEM outside vent door or inside via the new stove top lower cabinet back panel. This remote compressor location offers quiet operation and allows for a "natural convection" ...fresh ambient air intake and exhaust air rising/exiting thru the air shaft/roof top vent.
...in theory...?

The plan...
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