Fridge Performance Survey

[Civilguy]

Originally Posted by ZachO

Will turn the fridge on and test propane pressure this weekend.

Zach,

You're killing me with suspense here. Is this the "teaser" post?

I wish you would just post and tell us that you measured and corrected the gas pressure, and that the fridge is working better than ever, and then we can all go and live happily ever after here...

[ZachO]

Sorry! Part of the reason for those posts was to bump the thread since there were some unanswered questions previously. I thought maybe no one cared anymore

I wanted to install the new upper vent, but because it's right on the belly band, it's not a flat surface. The top and bottom are each at their farthest point out right there, and start getting more narrow towards the top and bottom as soon as they leave the seam. So the flat, rigid plastic was a problem. I thought of ways to build up something to make it work but in the end went back to the original top vent. I'll maybe find a way to install that new cover in the bottom vent for better air flow.

So I did this



This should get the hot air straight out instead of just swirling it around up there.

Manometer test showed



So I dialed it back a little at the regulator and it now sits here



I move back in the trailer later today so I just turned on the fridge this morning to cool it down. I'll let you know how it goes.

Of course our high today is in the 40s and rainy, with forecasted highs all week of only 70, lows in the 30s and 40s. Which is when my fridge works great anyways. Possibly I won't be able to really assess how it's doing till next July. We'll see.

[tractors1]

Originally Posted by ZachO

Sorry! Part of the reason for those posts was to bump the thread since there were some unanswered questions previously. I thought maybe no one cared anymore

I wanted to install the new upper vent, but because it's right on the belly band, it's not a flat surface. The top and bottom are each at their farthest point out right there, and start getting more narrow towards the top and bottom as soon as they leave the seam. So the flat, rigid plastic was a problem. I thought of ways to build up something to make it work but in the end went back.

If you can mail some heavy paper templates with dimensions you need I could probably fabricate some white ABS templates to use as shims to get you closer to a flat mounting surface. Thinking maybe large "U" shaped pieces you could fasten with VHB tape to the top and bottom halves.

[ZachO]

Hey, thanks. I appreciate that.

I think at this point it makes more sense to install it in the lower opening. After I cut the wood piece running across the upper opening, I started having second thoughts...So I put a new support beam across there. Seems like there's probably a good reason to have it there. With it there, there's really no way to install the new plastic vent cover without building up a whole exterior frame to mount it to. That would mean something sticking a couple inches out from the side of the trailer. Probably fine, but I do on occasion drag the trailer through trees and shrubs that could catch it.

It would be nice, since I'm going in there so often and all the holes are getting stripped. But I'll find a way to drill some threaded inserts in the shell or something.

[tractors1]

Originally Posted by ZachO

It would be nice, since I'm going in there so often and all the holes are getting stripped. But I'll find a way to drill some threaded inserts in the shell or something.

You could use a RivNut fastener with a backing washer for a threaded connection in the fiberglass. Very handy fastener in thin materials. A #6 size is probably all you'd need.

[ZachO]

Thanks!

It does have a wood frame behind the shell around the vent, so it's a bit thicker than just the fiberglass. I've wandered the hardware store aisles but haven't seen quite what I want yet. So for now I just put thicker screws in.

Those rivnuts look great. I'll just need to see if I can get a good view of how thick the wood is I'm trying to get through.

[tractors1]

Originally Posted by ZachO

Thanks!

It does have a wood frame behind the shell around the vent, so it's a bit thicker than just the fiberglass. I've wandered the hardware store aisles but haven't seen quite what I want yet. So for now I just put thicker screws in.

Those rivnuts look great. I'll just need to see if I can get a good view of how thick the wood is I'm trying to get through.

Ah, if you have some wood to screw into behind the glass, I'd go with threaded wood inserts. I use these a LOT when I need pieces to be easily removable.


https://www.google.com/shopping/prod...RoC3YkQAvD_BwE

[k corbin]

Originally Posted by ZachO

Thanks!

It does have a wood frame behind the shell around the vent, so it's a bit thicker than just the fiberglass. I've wandered the hardware store aisles but haven't seen quite what I want yet. So for now I just put thicker screws in.

Those rivnuts look great. I'll just need to see if I can get a good view of how thick the wood is I'm trying to get through.

Rivnuts are for thinner materials and they are great. But the issue with using them is they require specials tools to install them and those tools are expensive.

T-nuts can be used in wood and are not too difficult to use. They are not expensive. You will need access to the interior side of the wood blocking to install them. They have prongs which dig into the wood to keep them from spinning. As you tighten the screw you are putting into them the screw pulls against the T-nut. For a little extra security and waterproofing you can add some epoxy into the hole. You will be using a machine screw with them. Be sure you put some bedding compound or even easier rub some butyl tape into the threads to help keep the water out. Disadvantage the larger diameter hole for installation can weaken a narrow wood frame. Disadvantage they might develop rust.

Threaded insert are also a choice. You need to get exactly the right size of drill that matches the insert for drilling the hole to install them. Installing them can be a little tricky as you need to be very careful to drive them in straight, unfortunately it is easy to get them going in at an angle. There are tools made for the purpose to make it easier to drive them in straight but with some care a slotted screw driver also works. I do recommend using some epoxy when installing them to help keep water out of the wood the insert is threading into. That will harden the wood fibers and help reduce rot issues around the insert. Disadvantage, the larger diameter hole needed for installation can weaken a narrow wood frame. If you chose to use them get the brass ones, the steel ones could develop rust.

But just screwing into the wood works as you know and that is always my first choice because it is easy to do and sufficient for the purpose of fastening a vent cover. If the hole gets oversized push Epoxy Putty stick material into it. Let it cure then drill a new starter hole into it using the same original location. It is a great repair material for oversized holes, strong and waterproof too. I put buty tape around the screw threads, that keeps the water from creeping along the threads and rotting the wood. The excess buty tape will squeeze back out as you tighten the fastener. The butyl tape also reduces vibration and helps keep the screws from backing out but it won't interfere with removing them when needed. If it seems hard to remove them just heat up the head of the screw for a minute or so by holding a soldering iron against it. That will soften the butyl.

[John in Santa Cruz]

there are two kinds of t-nuts, the kind with the 3 teeth, those are only good for soft woods, there's another kind that has 3-4 holes in the flange, and you install with little #6 or so wood screws, these are more suitable for harder woods, if you pre-drill for the screws.

[ZachO]

Thanks again. The threaded inserts Charlie linked are more or less what I had in mind when I was looking at the hardware store.

I agree Karin, screws are the easiest. I've just had that upper cover off so many times now that a screw directly into a wood frame doesn't seem like it's going to cut it. That's why those newer style covers, with the screwed-in frame which stays in place and a "hatch" that opens are really nice. But with the bend in my trailer right there, threaded inserts and my old metal vent cover are probably best.

[ZachO]

Well, before putting this thread to bed for the winter, I’ll report some anecdotes. And the plural of anecdote is data, right???

With the lp pressure dropped down to 11 or lower, one thing that seems to happen is my food freezes less overnight. My fridge has a dial that goes from High to Off, Off being the lowest setting (no idea why).

Seems like when it drops into the low 40s, instead of actually turning the fridge off (really off), I can just put it at that lowest setting and food doesn’t freeze quite as often. In the past I’ve always turned it completely off if the lows will be around 40.

It’s only been getting into the low 80s on the hottest days, but I’ve had no problem keeping things cold. All day in the 80s and lows in the 60s would be the real test, but I think those temps are over this year.

Anyway, between the hole for the fan in the upper vent, and maybe the lp pressure things may be working better. Since cutting the hole, the fan doesn’t come on as much either.

So...that’s the status, until next July.

Thanks to all who helped, especially Mike who just can’t give up

[Civilguy]

Originally Posted by ZachO

Thanks to all who helped, especially Mike who just can’t give up

Yeah, I'm sort of like the party guest who won't take a hint, even when it's long past time to be headed home!

[John in Santa Cruz]

well, this last weekend, camped in ~100F weather for 4 nights, trailer parked in the sun, only shade from the awning and the popup awning I put due east (for morning shade)... 6.6 cu ft fridge-freezer in the escape running on propane the whole time, stuff in the fridge was below 40F, and the few items in the freezer stayed hard frozen.

[ZachO]

That's great. Not sure mine will ever do that well, but I think it may be to the point where I can limp it through high 80s. Probably 90s or higher and it's time for the cooler.