Constructing New Fridge / Freezer Boxes

[bobfnbw]

Thanks Nick.
If the box is tight, the very small areas between layers of foam should not be a issue I would think. Finding the foam is thick layers is proving to be dificult so far.
Locally I can find polyisocyrate foam, that has a R rating of R6 per inch, higher than any other foam, but only at 3/4" so far. Haven't tried everywhere yet.
But if its layered, with good plastic on the outside to control humidity, and the layers staggered, I would think it should be good.
I figured on vac panels for the top to reduce the overall thickness of the top but seems they are in short supply anyway. And the cost is higher than expected.
Bob

[hellosailor]

Nick, depending on the foam, a lot of it is moisture"proof", and our own Dept. of Energy claims that adding a foil layer to insulation can be effective at repelling radiant heat energy. So for foam that is designed to be installed in attics, facing the foil "up and out" toward the hot roof or hot room above it, is supposed to increase the effectiveness of the insulation by reflecting radiant heat back to where it came from. (The effectiveness gets lower as dust accumulates, etc. on the surface.)

That the same foil makes a good moisture barrier for marine use is another "if", because apparently the foil is intentionally made porous to prevent condenstation problems if the material under it is NOT already impervious to moisture.

No telling what's on the shelf in Home Depot.

[Badsanta]

I priced lids for the box a couple of years ago and R-parts was half the price of glacier bay but r-parts is plastic with a vacuum panel But I never saw one so dont know the quality. I saw a Glacier bay at the boat show and it was very nice. A solid gel coated fiberglass. Looked well made and a double sealed lid. Any one have experience with either lid? They were the only ones I could find.

[s/v Jedi]

I would make the whole lot myself with fiberglas. But I saw a custom Glacier Bay box once and it was super. It was top opening but part of the front opened toward you with gas springs too because there was little room above the box. It was like the doors of a Lamburgini. But the cost....

ciao!
Nick.

[bobfnbw]

Well yes the cost is high, but so are custom refrigeratiors people are putting in their homes now, and the boat fridge is a lot more important we all know....
I have a thermador fridge at home. I think the price was 6000 new. Got it scratch and dent thru ebay for less than 1/3 of that if I remember right. In fact you could build a whole house for what people are spending in their kitchens these days.
A good freezer and fridge is essential to us for cruising. But the cost is of course high especially if you do it wrong. The cost of running a engine daily for hours on end to just power a small fridge is more expensive in the long run.

I want a small, say 3 cu.ft. freezer and a 6 cuft fridge. Powered by frigoboat air cooled systems. I think the days of large compressors and holding plates are over.

I would gladly use vacuum panels if I could. But there might not be a reason to do it. Any larger boxes and my planned system will get to large to be as energy efficent as I planned. or hope to have.
Bob

[witzgall]

I think Isocyanurate foam panels will absorb moisture, degrading their insulating qualities over time. This can be signficant. One a house, the moisture can escape. In an icebox, it cannot.

Chris

[s/v Jedi]

Okay, here's some nice info about Dow styrofoam:

:: FOOLPROOF DIY SKATEBOARD FOAM MOLD BUILD

and

Toothless: Longboard Construction: Foam molds

cheers,
Nick.

[bill good]

VIP'S have about 10yr life & should be known as VEP (very expensive panel). I removed the engine driven eutectic systems & went for 2 DC compressors. Using the old boxes it need 100A/per night. (18hrs dark 6hrs sun) 100ltr freezer -12deg C + 48ltr refrigerator max +5deg C.

Regards Bill Goodward

[hellosailor]

BTW, if you plan to use a hot-wire cutter for foam, keep an eye out for an old fashioned toaster in the trash. The new ones use "quartz rods" but the old ones use nichrome heating wire wound on ceramic elements, and you can easily unwind some and use it for the hot wire. Nichrome wire is designed to heat up fast. (It can also be bought in spools, but of course dumpster diving is recycling.)

We used to just use the nichrome wire on line power, and be very very careful not to touch the bare live wire. Battery power just might be a safer way to go. (G)

[Stevens 47]

I am re-insulating my existing box's. Found this stuff that has a R10 value per inch. Pricey but not as much as VIP's Aspen AeroGel Spaceloft Insul-Cap -Anchor Companies ASPEN AEROGELS | Case Studies

I did spring for new VIP top hatch system from Rparts though.

[Tspringer]

I just spent over an hour typing a very detailed followup to this thread all about how great my fridge and freezer turned out and how happy I was with them. Then I hit the wrong key and somehow the entire thing vanished. Its really not my day.

Suffice to say.... the frigoboat stuff and the Glacier Bay VIP panels are AWESOME. We have incredible fridge and freezer that work better than expected and use only about 65 amp hours per day. I am VERY happy with the systems, had no issues getting it all installed and working and would highly recommend Glacier Bay and Frigoboat.


Terry

[Extemporaneous]

Originally Posted by Tspringer

I just spent over an hour typing a very detailed followup to this thread all about how great my fridge and freezer turned out and how happy I was with them. Then I hit the wrong key and somehow the entire thing vanished. Its really not my day.

Suffice to say.... the frigoboat stuff and the Glacier Bay VIP panels are AWESOME. We have incredible fridge and freezer that work better than expected and use only about 65 amp hours per day. I am VERY happy with the systems, had no issues getting it all installed and working and would highly recommend Glacier Bay and Frigoboat.


Terry

Sounds great.
Have you ruled out a rewrite?

Just asking,
Extemp.

[delmag]

terry-
it is my understanding that there is a limit on the size of any individual post and that there is no warning when the size is exceeded.....it just vanishes. this may be what happened to your follow-up. multiple, smaller posts seems to be the needed workaround.
that being said, i'm glad to hear you are happy with your results. i am just about to start on building a reefer box and was considering using the glacier bay VIP panel with the molded lids (for the top only) to save myself some space and effort. would LOVE to hear any details you'd care to pass along that you think might help me end up as happy with my installation as you are with yours.
-del

[James S]

Ditto and ...any pictures Terry?

[olliric]

Originally Posted by s/v Jedi

Terry,

I have been where you are now, taking 3 months to build three new boxes in 2005. This is what I discovered and how I did it:

First, reset your brain, purge all your current thoughts about the project, just while reading the rest of this post. After that, compare and make your decision.

My first discovery was that vacuum panels were not going to happen. Even the Rparts panels (which are way cheaper) were still outrageously expensive. I could afford it but realized I was not crazy enough to spend that much money on this. VIP's were quoted at $7,800.- to get the idea.

So, what I want to say is that it is much better to have a smaller box with more insulation than the other way around. If you plan to sail into the tropics and not run a genset hours each day, design a fridge with 4" foam and a freezer with 6". A 6 cubic feet box with a BD50 compressor unit will run about 20 minutes each hour, a duty cycle of 1:3. This is for both freezer and fridge because the freezer has more insulation and is opened less.

Start with the selection of foam. Use pure refrigeration foam, 2" and/or 4" thick, no reflective coatings or plastic lining or whatever, because you are going to have several layers and you don't want anything in there that conducts heat better than the foam. Use expanding spray-foam as the adhesive.

Now, you have to make a rectangular outer box where you can put the foam in. When the space for the box isn't rectangular at all, like against the hull, use 1/8" plywood, some 1"x1" battens and a tacker to create the biggest possible rectangular box. You will remove it later, so nothing fancy. Use the 1"x1" battens for the corners but also for plenty supports/struts inside the box to keep it in shape. So, give the box a bottom but no top.

Next, use spray glue to put plastic foil on the outside of this wooden box, except the bottom of course (can't reach it). Use epoxy and roller and brush to coat the inside of the space around the box (like the side of the hull, inside of front-cabinet wall, etc.) Let the epoxy gel to the "very sticky" phase and use it at that moment as the adhesive for aliminium foil, which you put in with the shiny side out (shiny side facing the hull). The epoxy and foil are the moisture barrier and the radiation barrier.

Next, measure one outside of the box (largest measurement) and cut a piece of foam. Parts, like the bottom edge, will need to be tapered. This is easy, use a bread knife and a surform rasp. You can get it to fit pretty quick and every panel will be faster. Spray some expanding foam on the bottom edge (or just into the space down there) and put the panel in. Use masking tape at the top to hold it against the plywood. Keep going on until all is filled up. After that, remove the plywood and plastic foil.

You are now left with a big hole where the bottom should be. You can use sheet-foam or pour 2-component liquid expanding foam (but go slow, 1 mixed cup at a time). Use the surform rasp (after fully cured) to shape it when pouring went a bit out of hand.

Now is the time to decide on minimum isolation thickness and interior volume. I would advise a maximum of 6 cubic feet interior. You make it smaller by putting in more panels on the sides and bottom.

Next is the lining. Easy but time consuming when you want it to look pretty. Start with a sheet (or half sheet, do the math and jigsaw puzzle on paper first) of 3/8" marine plywood. Put it on a level bench or A-frames. Using a black permanent (thin point) marker, draw out all the panels you need for the inner lining. Make the bottom piece the full size so that the walls stand on the bottom.
Don't use the existing edges of the sheet (stay a half inch away from them) anddon't cut yet! Vacuum it.

Drape the lightest fiberglass cloth over the whole panel (in 1 piece) and cut it so that a couple of inches hang over the sides, like a table-cloth. Now start mixing batches of epoxy resin + fast hardener. Pour the first batch (6 pumps if using West System is a good start) in the center of the sheet and use a plastic spreader to spread it. It must become completely transparent without trapped air. This is really easy. Works all the way to the edges and ignore the overhang. Let cure until gelled (still sticky) and add another coat. If the spreader becomes difficult to use, switch to a roller. Continue this process (start in the morning) until the cloth is completely under the epoxy. Let cure for 24 hours; it'll look like a varnished panel and the cloth is only visible at the overhangs.

Cut away the overhang with a sharp knife and smooth it with very course sandpaper (don't cut yourself on the edges, very sharp). Turn the panel over. Use brush and roller to coat the backside and edges with epoxy (fast hardener again). Let fully cure. Dry-sand (wood fibers come up after first layer of epoxy) and coat again. Let fully cure.

Turn panel over again and wet sand it (with orbital sander). Hose it wet and sand; rinse with hose and look how the water flows over the panel: look for any "rapids". This is where you must sand more. Stop sanding when you hit the fiberglass. This is where you decide how pretty the end result must be. You can roll on more layers of epoxy or decide it's good enough.

About the wet sanding: only use the machine when the hose is away and excess water is off the panel. Use a double-insulated sander, which is every modern one I think (label on sander states that with 2 square symbols, one inside the other).

Now you cut the panels. The lines drawn on the wood are as clear as before the epoxy and glass went on.

Put the panels in the box, using very little spray foam (just couple of dots) to hold them in place and immediately put some struts in to force the walls onto the foam. Don't put the top on yet. Use angle to check it is as straight as you want and don't worry about some small openings where they meet. Use thickened epoxy to put fillets in. I used Coloidal Silica to peanutbutter consistency and those West System fillable caulking tubes for a quick job.
Now you have the best excuse in the world for buying the Fein Multimaster tool. You can get sanding attachments to sand the fillets to perfection. Alternatively, use a short piece of hose with sandpaper around it but I ended up with RSI from that job.

Sand everything incl. the underside of the top. Now you can paint it, the top still off the box. I used Awlgrip which is safe (but still not food grade may be) after cure. Don't use white paint with lead.

Now, drill the holes for freon lines. The connectors of the evaporator determine the size. Mine just fit through a 1-1/4" thin-wall PVC pipe. Use PVC pipe, it's the moisture barrier at the most important spot because the freon lines will create condensation. I used a 10" long 1/4" drill bit to drill a pilot hole through the whole lot first. Next was the hole-saw from both sides. I used the PVC pipe itself to cut away the foam. Make the pipe 1/4" too long so that each end stick out 1/8". Use silicone sealant to close the gap around the pipe... do this good, absolutely watertight.

Install evaporator, sensors etc. as the top is still off so easy access. I installed compressors and everything at this phase and tested the system to be sure all the equipment was good. Afterthat, I used silicone sealant to put the top on (don't use stronger, silicone is tough enough and leaves hope to get it off later, if ever needed).

Now, you hopefully didn't forget room for the insulation at the top I hope. Put the sheets on, level the surface with batten and surform rasp. Now, stab the bread knife in what you think is the center of the opening and start cutting to a side. Cut the opening out. Epoxy brush/roller the foam and aluminium again. Should look like a spacecraft part now. Fit collar, lid and counter top, ready!

Some detail photo's attached.

cheers,
Nick.

Hi Nick,
It looks like you are enjoying the San Blas. Lucky you.
Not there yet for me, I am building a 15 sailing cat and I am designing the fridge and freezer. I need some advice on the choice of compressors and evaporator size.
The basics are:
3.3 Cuft freezer, 6" Expanded polystyrene R5/" insulation
6.3 Cuft fridge, 4" Expanded polystyrene R5/" insulation
Frigoboat keel cooler system, one per cell
Evaporators two 160F
Compressors two K35F
With the Frigoboat instruction sheet I have calculated an energy consumption of 23.5 Ah/day for freezer and 21.2 for fridge. I will run the boat in the tropics on solar panel only so I would like to make the most energy efficient choice of compressors/evaporators. I don't drink much beer so the time to lower the temp. is not that important.
There is a lot of contradicting information on both the US and Italian Frigoboat sites. It is either the F160 or F200 evap and BD 35 or 50. Maybe your on the field experience may shed some light

Questions
1- What is your Ah/day consumption of your cells?
2- How many hours they run per day.
2- Why did you choose the BD 50 instead of the 35. With 6 cuft cell like you have the 35 should be enough. The 35 should make the system considerably more energy efficient.
3- What size evaporators you used?
5- After using it for some years what are the impressions?
6- What would you do different if you were to do it again?

Thanks for the feedback
Cheers
Giovanni