Keeping Refer Cold

[zero]

I'm just citing what Dometic gives in their diagnostic manual as a ballpark figure. I've never camped anywhere that gets over 85 F for more then a few hours so I've never had to give it a lot of thought. I DO know the compressor refrigerators work much better in severe heat, as compared to the older 3-ways. The newest ones claim to be 30% more efficient on propane usage, but I have no idea if they actually cool any better.

[paulnptld]

My older Dometic 3 way stays very cold, even at Burning Man where temps are near 100 degrees. I generally set the thermostat to 5...but also added a few Freez Paks to help regulate the temperature.

http://www.amazon.com/Lifoam-4942-Iceberg-Reusable-ounces/dp/B000KIR5PA/ref=sr_1_1?ie=UTF8&qid=1409629361&sr=8-1&keywords=freez+pak+42

[MontanaChinook]

I made my appointment during busy season...so I finally get to take it in to get looked at next week. I'll let you know what they find.

[MontanaChinook]

Well, I didn't exactly get the answer I wanted...

They didn't even really do much testing of the fridge, because of an "improper install". If I look back at the installation instructions, it shows a vent at the top and bottom of the fridge. The way my camper is set up, there's just a vent at the top. And the hatch to get at the fridge controls from the outside is at the bottom. Kind of a vent since it doesn't seal very tight, but not really.

Also since the new fridge is a bit taller, the top of the top vent is level with the top of the fridge. The install diagram shows the vent should be slightly above the fridge.

So all the shop did was verify that it only got down to 55 degrees, on a 50 degree day. The gas works (which I knew), and the electric works.

So their plan is to add another 2 vents. One to the bottom, and another to the top, above the current top vent. That's fine...

My problem is that he figured the fridge never worked the way it was installed. When I asked him why, then, did it work completely fine for 4 months, he had no answer. He figured it never should have worked.

So...improper install or not, I don't want to either pay them the $360 ($100 vents from Dometic, plus four hours labor), just to find out that yeah, I didn't do a great install, but there are more problems and it still doesn't work.

So my only real question at this point is: would it make any sense at all that if it worked fine for 4 months, then quit, that simply adding the correct venting is going to fix the problem? Or did I likely cause more problems by overheating it?

I get that they don't want to do a bunch of tests and rack up the labor costs, when it's obvious to them just looking at it that it doesn't have proper ventilation. But I'd hate to have them do the vent work, or do it myself, only to find that the cooling unit is toast.

Just curious what your take is...

[Maineah]

It should work sitting on the floor I agree with you if it worked for several month why would vents fix it now? The venting for the condenser is the most important, doesn't the outside door have vents in it?

[MontanaChinook]

The outside door does not.

[MontanaChinook]

This is the best photo I can find which shows the fridge and the vent together, before it was installed. Not sure what the deal is with the big bulge in the fiberglass in the center. That's just how the Chinook was built.

So there's a vent on top (but just high enough to come level with the top of the fridge), and a solid door on the bottom.

So...I am interested in whether this is enough ventilation. But also...if not, would it make any sense that it would work at first but then stop? And if the lack of venting caused it to stop working, what would it have actually damaged? Is there any chance at all that just venting it would fix it?

Seems like so far people think no, and I agree, but I really don't know.

[linda s]

Take your fridge out and have them retest it. If it still doesn't get cold with all the ventilation of open space something is wrong with it. Just have them plug it in to 110. No colder means it don't work

Linda S

[MontanaChinook]

Alright, thanks.

So...take it out, have them test it again. Good idea. If it tests fine, look into either cutting more holes in the side of the Chinook or making some sort of chimney.

If it doesn't test ok...wonder if I officially voided the warranty?

[linda s]

Alright, thanks.

So...take it out, have them test it again. Good idea. If it tests fine, look into either cutting more holes in the side of the Chinook or making some sort of chimney.

If it doesn't test ok...wonder if I officially voided the warranty?

The guys who inspected it already said your only problem was ventilation. If it doesn't work outside your camper ventilation wasn't the problem so how did you do the damage. It worked fine for 4 months. It broke. Accept no other answer.

Linda S

[linda s]

Are these guys that tested it Norcold service representatives? Kind of worry's me that they didn't test it properly. I mean they should have tested the heaters for 12 volt and 110 and circuit board. Kind of sounds like they didn't do their job and just tried to get some money out of you by doing alterations to your camper. See if you can take the fridge somewhere else for the next test. Call Norcold and tell them your not happy with the guys they sent you too. If ventilation was the problem it never would have worked right.

Linda S

[Maineah]

The cooler the condenser runs the better the fridge will work but it still should cool in your situation it's not like it's confined in a box it may make the camper warmer but it should cool. Just for a test put a fan behind the fridge where it is and point it at the condenser that will be all the venting it will ever get.

[MontanaChinook]

Well here we go again. You can see, a few posts back, a photo of my fridge, mid-installation, that more or less shows the space I'm dealing with and the location of the vent.

The installation manual shows that the vent needs to be above the coils. You can see in the photo that the top of the vent is about level with the top of the coils. There isn't enough room for another vent right on top of that one, even though that's what the repair guy wanted to do, because the window starts right up there, and my counter top would cut the vent in half. You can also kind of see in the photo that for reasons I can't figure out, Chinook put a large bulge halfway up the back of the fridge location. So putting fans at the bottom of the fridge pointing up would blowing mostly into that, instead of the coils (though maybe it would still move enough air around?).

It seems that Karin has been in here doing her post deleting act again, because I remember her saying something about a solution of putting a chimney in there above the back of the fridge but it's gone now.

As far as getting as close as possible to the Dometic instructions "correct installation", a chimney would be the best. So...unless you think this is totally unnecessary (let me know), I'm trying to get some ideas of the best way to do this. If I'm going to cut a hole in the camper, I want to think this through a bit first.

My plan is to use pvc, probably just a couple inch diameter, as the chimney pipe. Rather than running straight up through the whole camper and out the ceiling, which would mean cutting a hole in the roof, I'm thinking of just going up probably a foot, then a 90 degree turn out the side of the camper. And figure out some way to put a screen on the extruding part on the outside so it doesn't look terrible.

So...will this vent hot air? Is 90 degrees too sharp? Would just throwing a computer fan or two in there somewhere, anywhere, blowing on the coils have more effect that this, without cutting any holes in my camper?

Thanks.

I went ahead and added the photos to this post to make it easier. This is what I'm working with. Since these photos were taken, I have boxed all of this in.

Notice the big obstruction mid way up the back of the fridge, and the countertop. Chimney in there somewhere? Or just fan(s)?

[linda s]

So did the fridge get cold properly when you removed it and it had more ventilation? What is that bump. Purpose? Yes I think ducting with a fan would vent it fine even with the turn. AC and heating systems in buildings and homes have 90 degree turns all the time. As long as the turn isn't constricted, smaller.

Linda S

[MontanaChinook]

Yes, when I brought it in the house and plugged it in, it seemed to cool properly. Got down right around almost 30. No way to test it in the camper on gas until it's warmer than freezing outside...so probably March or April, after it's all put back together and I'm on the road. Oh well.

Well, I was thinking two different things. ONE would be putting a fan in there somewhere, blowing on the coils. Period. TWO would be putting in the chimney, no fan.

I mean I could put in the chimney and put a fan in there, which if I do the chimney, I likely will, because why not. But first, before I go cutting a hole in the side of the camper, I was wondering if anyone thought that putting a fan in my existing setup (no chimney), blowing on the coils, would do just as much as a chimney. And save myself the hole.

If I just put two computer fans on the top of that bump, pointed at the coils, that would definitely move some air around. But enough? Enough to keep from cutting a hole in the side of the camper? I don't know enough to know...

The bump is pointless, so far as I can tell. I mean I know it has (had?) a purpose, but to me it seems completely worthless. There is no storage on the other side. It's just part of the fiberglass mold, which seems to have been built to purposely stick out into the back of the fridge and divide the bottom half from the top half, a bit. I really don't know.

[Maineah]

Many do not have a chimney per say some go to the roof some just exit the side both work, my camper and MH both have side vents. All you need is an area for the heat to escape. The vent does need to allow for a draft of some sort to keep the air moving and I guess that's why they say to keep the condenser lower to promote a draft I'm going to say the condensers on mine are about midway in a 2 foot chimney vent. Fans would work but a natural draft is all they use in normal operation. The outside vent area is about 10" X 20" both top and bottom. If you have to use fans they should work installed at the bottom (fans push a lot better than they pull) and a forced draft does not need to be as big. Computer fans are pretty efficient and don't draw a lot of power but they pretty much would have to run as long as the fridge was on.

[MontanaChinook]

Ok, thanks.

I just measured and even if the counter top wasn't right at the halfway point, there isn't enough space between the top of the existing vent and the window to fit another vent. Just not enough space.

So I'm either looking at just fans, or a chimney. The chimney won't be big; like I said, probably just a couple inch wide pvc. Draw is what I was worried about with the 90 degree turn out the side of the camper.

Also I think you mentioned before that if I put a vented door in place of the solid side access door I have right now at the bottom end of the fridge, that would help. So I'll need to look around for one of those, too.

[WME]

Hot air rises and has to go somwwhere. Ithink your answer is a vented door and chimney with a small computer fan in each chimney.

Go to ebay and look for snap switches. They will work great for turning the fans on and off.

[MontanaChinook]

I saw a fan somewhere in my searches with a thermostat...automatically turns on at 100, off at 80, or something like that...Not sure of the quality. But yeah, wiring an on/off switch into the fan would definitely be a good idea if I get a regular computer fan.

So, so far it's looking like cutting a hole in my camper is the way to go.

Anyone have ideas on what sort of end cap to put on the chimney? It's likely going to be sticking out the side of the camper straight out at 90, or maybe 45 degrees. What's something that wouldn't look terrible but would keep bugs and the worst of the rain out?

[Maineah]

I think your biggest concern is air volume can't you just use a louvered panel in the side of the MH? I just think as long as your using fans the air flow will be adequate. Cold air in the bottom hot out the top. As far as a thermostat that maybe some thing you will have to play with so some thing with a sensor fastened to the condenser and adjustable. Find the best condenser temp to equal interior fridge temp.

[MontanaChinook]

As to the louvered panel (had to google that one ), yeah, I've thought about that. The problem is the space I'm working with. There is only 5" between the top of the current vent, and the bottom of the window. RV side vents seem to all be at least 13" tall. But even with a smaller one that would fit in a 5" space, my countertop still runs right through the middle of that 5".

I mean maybe 1 or 2" of vent just above the fins is enough to cool adequately. Problem is, I just don't know. So it's seeming like a little pvc chimney and maybe a fan or two is going to be my best bet.

You're taking it a step farther...You're saying to find an adjustable temp sensor, measure the temp around the outside of the fridge at the fins, and compare that to the inside temp of the fridge, and adjust the fan to come on based on that ideal temp?

That would be really forward looking of me to do that, rather than "how can I just get this thing to cool properly"...

I just keep thinking back to last spring and summer, when it worked perfectly, in 40-90 degree weather. With no fan, and no top ventilation.

I'm still afraid that whatever went wrong is still wrong, but short of bringing it to an actual shop and paying them, there's no way for me to test it until it's warm out again. I'm not in Montana this winter, where I know enough people to find a large enough heated garage that it would fit in, to test it. So it's parked outside.

So...I'm just looking to get the install adequate enough to meet the installation manual specs, and cross my fingers that it'll work come April.

I think for now I'll just wander the hardware store and look at chimney stuff and see how I think that'll all come together.

Thanks.

[darrel]

I put two 48 volt 5.25 inch computer fans at the top of my frig. Fans run slower at 12 volt but still push a bunch of air. Mounted them above the frig because it was a lot easier to do so. I cut a panel out of the chimney and made it so I could get access if I needed to. Wired a on-off switch, the blue light. Tapped into the 12 volt wiring behind the speaker to the left of the frig chimney. When the outside air temp is say 90 degrees, refer on, and the chimney temp is 117 degrees, the fans on will drop the chimney 15 degrees. I drilled a 3/16 hole in the removable panel and pushed digital meat thermometer in. It makes more of a difference in refer temp when the outside humidity is high. In dry, low humidity the refer does not build up near as much frost on the inside and is easier to cool.

[rad wolfe]

straightforward & well executed!

Can you still use the the thermo for cooking meat ? I always liked dual purpose gear.

[MontanaChinook]

Nice, thanks.

[darrel]

Yes I can still use the thermometer for cooking. I also drilled a hole into my refer door and inserted a thermometer. Push a button and see the inside temp without opening the door and trying to find the thermometer.

[WME]

Go to Home Depot and look for soffit vents

[Vanman]

You just need circulation. Put a vent on the bottom, one on the top and an exhaust fan on the top vent. That will move more air than the battery powered fans I have seen some use. If you can do that what do you need the chimney for ???

[MontanaChinook]

So people think 2" of vent up top is enough, then?

That's all the space there is.

So I guess I could put a couple of these in. Like Maineh said fans are better at pushing than pulling, but a couple computer fans in each of those might work...

I won't be using battery powered fans, that's for sure. Well...they'll be 12V powered by my coach battery, but you know what I mean.

[WME]

Hows the project going???

[Maineah]

The little computer fans draw very little current and you could all ways turn them off at night. The very best place would be right under the condenser blowing up across the fins if you really want to be fancy use a snap thermo switch attached to the condenser inlet pipe to come on only when needed. Some thing the likes of this http://www.zoro.com/i/G3923787/?utm_source=google_shopping&utm_medium=cpc&utm_campaign=Google_Shopping_Feed&gclid=Cj0KEQiA1NWnBRDchObfnYrbo78BEiQA-2jqBfhJWUBpub3B_Gs0Q53qbG3wnL1aZ-gQKrXnHO0nuMUaAk478P8HAQ

[MontanaChinook]

Good! I mean, not at all. I bought those vents I linked in my last post. But it's been cold, with warmer weather forecasted. No reason to work in 20 degree weather when 30s and 40s are forecasted in a few days.

So for now I've been prepping my engine and gathering parts while the head was at the machine shop. Got it back yesterday. So I've been cleaning off piston heads, cleaning up oily crud all over my engine, etc.

Head will likely go back on this weekend, then oil pump and front crank seal replacement. Once I know that I can get in the camper and drive it when I'm ready, I'll start work on coach stuff. Want to make sure I can get out of town, first.

But next week I'll be cutting the holes for those vents. I'm going to wait on spending money on fans until I'm sure my fridge even works. I mean last summer it was DEAD. If it starts working again this summer it won't be cause I put a couple vents above it. It worked fine for four months without those vents.

So for now we'll just do a "proper installation", aka vents where the installation manual says they should be, and see if my fridge is functioning. Then, later in the summer or whenever, I'll look into some fans, if I think I need them.

[snail powered]

I saw these very affordable rectangular ABS louvered vents at our marine supply store the other night. They would give more air volume transfer than a round sofitt vent without being overly large. They are nice quality. You have to click on the color choice to bring up the dimenions.

http://www.fisheriessupply.com/sea-dog-line-louvered-vent-plastic

[MontanaChinook]

Thanks Karin. Those would be really nice, but are still too big to fit in the space I have to work with. Hopefully 3 of those little 2" vents in a line will allow enough flow.

[WME]

Small fans inside the vents. 3 of these would move around 45cfm which should be a big improvement over gravity flow.

http://www.ebay.com/itm/5pcs-12V-Mini-Cooling-Computer-Fan-Small-40mm-x-10mm-DC-Brushless-2-pin-/231353956765?pt=LH_DefaultDomain_0&hash=item35ddc5399d

A little dremel work should get them inside the vent housing.

[Maineah]

I agree your vent space is not real large you're only around 18 square inches with 3. The top vent in mine is 190 square inches right at the louvers and pretty much the same at the bottom. You kind of need a forced draft.