Let's talk about refrigerators

[Eggscape]

Just looking at the diagram and it appears like all the action happens on top of the fridge.

This would require a duct up from the side vent directly into the back of the coils using the fans to create flow like they do now...then the hot air up and out the roof vent.

A real pain...I can see why they are looking for a different model if they want to use the outside vents for cooling.

[JulietF]

I think this trailer will be with us for years so am not worried about going back to an absorption fridge. As for the fibreglass work, I think it is very doable. Having owned many different sailboats over the years I have spent more than my fair share of time grinding out blisters, repairing booboo's and fixing keels. Access will be the trickiest part.

[Mike G]

I can see Eggscape's point. I read someplace that the coils on the rear of a compressor fridge need some ventilation space and air circulation. The typical wall and/or roof vents seem relevant for this task of keeping the coils from getting too hot.

Juliet, I'm still confused about your description. On the one hand I think you say the rear of the fridge (which is exposed to the outer vents, right?) is sealed off from the interior. On the other hand I think you're saying that, when it's cold outside, the cold air from the outer vents on a cold day is causing cold air to blow on you while cooking. In my mind, the two seem mutually exclusive. If the cold air is from the fridge's interior, it should always be cold (consistently) when it comes out at you. If it's only cold on you when it's cold outside, that would lead me to think that the air which should be routing to the upper vent (and sealed off from the cabin) is exiting into the cabin when it shouldn't be. Or am I just confused? I really don't get why any air should be blowing on you, unless you open a window, vent or door!

[JulietF]

Originally Posted by Eggscape

A real pain...I can see why they are looking for a different model if they want to use the outside vents for cooling.

Is that what they are say, they want outside air for cooling? The fans on these refrigerators are pretty strong and the air originates from inside the trailer, I can't see an upside in drawing air from the outside to cool help cool the fridge.

I can see an upside in getting some airflow happening in the vent area to keep it from overheating......which in turn would help the fridge stay a little cooler.

[JulietF]

Originally Posted by Mike G

I can see Eggscape's point. I read someplace that the coils on the rear of a compressor fridge need some ventilation space and air circulation. The typical wall and/or roof vents seem relevant for this task of keeping the coils from getting too hot.

Juliet, I'm still confused about your description. On the one hand I think you say the rear of the fridge (which is exposed to the outer vents, right?) is sealed off from the interior. On the other hand I think you're saying that, when it's cold outside, the cold air from the outer vents on a cold day is causing cold air to blow on you while cooking. In my mind, the two seem mutually exclusive. If the cold air is from the fridge's interior, it should always be cold (consistently) when it comes out at you. If it's only cold on you when it's cold outside, that would lead me to think that the air which should be routing to the upper vent (and sealed off from the cabin) is exiting into the cabin when it shouldn't be. Or am I just confused? I really don't get why any air should be blowing on you, unless you open a window, vent or door!

Oh dear, I am not doing a good job of explaining it.

The fridge is a closed unit, all the air movement is inside the fridge in vents which are located on the bottom, top and back.....vents appear to be as wide as the fridge and about an inch high on the top and bottom.

The air is taken in from the interior of the trailer on the bottom of the fridge, it moves along the bottom of the fridge to the back, then up the back to the top then along the top and out into the trailer.

When the air in the trailer vent area behind the fridge was cold, the fridge air discharge at the top of the fridge was cold. I am guessing this is because the back of the fridge was cold from exposure to the cold air in the trailer vent area which in turn cooled the fridge vent air as the air passed by the back of the fridge in the fridge vents.

These were cool days where the temps were dipping to +1C at night. When sealed up the trailer vents and did some insulating it definately helped with cold air coming out of the fridge vent.

[JulietF]

I think in part what I am trying to say is that the fridge vents are doing a good job supplying cooling air to the coils ( from the interior) they dont need to be kept cool with outside air in the back of the fridge. The cold air in the trailer vents cooled behind the fridge cooled down the fridge vent air too much, making it uncomfortable when standing close to the fridge vent discharge.

The confusion is coming from using the word vents to mean two things, the fridge vent inside the fridge and the trailer vent outside the back of the fridge.

[Eggscape]

Maybe a picture will help.

The red circle indicates the external coil that dissipates heat is in this silver duct where air is forced by. The compressor is on top beside it. I am not sure of the air flow but in and out is done by the grill on top. There is nothing really on the back of the fridge. It could be up against a wall with no ill affect.

[hotfishtacos]

These DC compressor refrigerators have different configurations; one where the unit recirculates air from inside the trailer and the one I installed that is more conventional where the air intake pulls air in from outside behind the refer, air flows up over heat exchange coils behind the refer (like a home refer) and eventually exhausts out the top of the trailer. These air flow ports were already there when I pulled out the Dometic refer. I also chose this configuration to eliminate any possible trailer space heating from the refer. It has never failed to operate flawlessly regardless of the weather.

[Brian B-P]

Juliet, your description was clear to me from the beginning.

Even some residential refrigerators have both bottom intake and top exhaust vents on the front, and I don't think many still have the coils on the back. It seems that coils are most commonly in the bottom now, and are typically on top of those models with the obvious top grille (such as the classic Sub-Zero).

I realize that it may seem obviously preferable to exhaust refrigerator heat to outside... if you assume that the trailer is only used in hot weather. For many people, that's not valid. If it is hot, and you have air conditioning (which many Escape owners assume is absolutely required for civilized "camping"), then forcing the refrigerator to pump heat from near freezing to the high outside temperature just reduces it's performance. Even if you don't want extra heat inside, most of the heat from the refrigerator came from the trailer interior anyway, so running the refrigerator without dumping heat to the outdoors doesn't heat the interior very much; a few dozen amp-hours per day is less than one kilowatt-hour per day.

[AllanEdie]

Spot on. Our danfoss type fridge on the boat is at least 20 feet from where we sleep, isolated in a separate storage compartment, and it is clearly audible from anywhere in the boat. I doubt that it wakes me up, but it annoys the hell out me if it turns on when I am trying to get back to sleep. I expect that it would be intolerable to me if the same unit were mounted inside our 21.



Our propane fridge in the 21 works flawlessly, and the one in our camper did likewise for 20+ years with only routine maintenance. I would not trade the new fridge for an electric, and I have used both for many years.



One needs to keep in mind here that panels mounted flat on the trailer roof rarely collect what they are nominally rated for even in direct sun. So, be careful of your arithmetic... We use two deep cycle 6V agms on the boat, exactly the same batteries as in the 21, and with the small danfoss unit in the boat, about two days is all we get before a recharge is required. A larger electric fridge would deplete them faster.

[snas]

Originally Posted by JulietF

We ordered our trailer without the vents and were gutted when we saw them. Last fall was a crazy time for Escape, lots of changes and lots of confusion. Escape has acknowledged we fell through the cracks and has been working with us. They are supplying the hole cutouts, decals and gelcoat. We are supplying the fibreglass supplies and doing the work.

JulietF, was the factory order to have neither exterior side nor roof vent and now your plan is to glass over both. Or did it/does it only involve the side vent ?


I've thought about internal venting for modest cabin heating at night but it sounds like that might not amount to much. As for the cold discharge air, is it possible to redirect the output, either with a deflector or via a new output to the dinette side of the cabinet ?

[Mike G]

Originally Posted by Eggscape

Maybe a picture will help.

The red circle indicates the external coil that dissipates heat is in this silver duct where air is forced by. The compressor is on top beside it. I am not sure of the air flow but in and out is done by the grill on top. There is nothing really on the back of the fridge. It could be up against a wall with no ill affect.

I get it now. A picture really is worth a thousand words, thanks.

("I see, I see!" said the blind man as he stumbled in the dark....)

[Tin]

Originally Posted by JeffreyG

Short background, I'm planning my E-19 build for an RV that will mostly be boondocked, only occasional electric service. Three season use, but not extreme winter most likely.

I'm planning two 100 Ah lithium batteries with a Victron battery monitor. I will install my own 240 watt rooftop solar panels routed through a MPPT solar charger.

My base plan is the upgraded 6.0 cu. ft. propane/120V fridge. I've owned this exact same fridge before in another RV and for me it was reliable and even a bit bigger than I absolutely needed (which is a plus). Here are my only concerns with the 6.0 cu. ft. fridge:
1) Requires both roof and wall vent panels. In particular if there was a way to avoid the roof hole that would be nice.
2) In my last RV, this fridge had a fan that would click on-off-on-off at a pretty high frequency. It was annoying late at night if awakened. Maybe I could have fixed this by moving whatever temp. sensor was triggering the fan, but I never dug into it.

Another option on the Escape is 12V DC.....either their standard option or I could provide a front venting unit. These might allow deletion of the roof vent and they might be quieter. But there are downsides:
1) Big draw on the batteries. Maybe my 240watt solar could keep up in sun, but I'm probably into portable panels if I camp in the shade.
2) Much smaller fridge for more money.

My knee jerk reaction to the build sheet was to opt for a nice, big propane fridge. That might still be the smart choice but I'd love to hear any thoughts plus or minus for other options.

Hi Jeffrey, the 6.0 Americana propane frigs installed in second gen trailers are excellent frigs. Ours works great in high temps and high elevations, of course I completely resealed the frig comportment and insulated with 1.5" Foil Faced
Fiberglass Duct Insulation along with a Tex fan in the back for those really hot days.