Refrigeration Box Insulation

[skipgundlach]

PS I didn't see any spamming on his site: KollmannMarine Boat Refrigeration Specialist

Was this the one you went to? Great sections on the how-and-why of what you likely have now being nearly worthless (box issues, not the machinery, which may or may not need upgrading).

L8R

Skip

[fawcettm]

Thanks lots of information here to think about, I was reading about some polyurethane called FROTH-PAK from DOW a step up from the great stuff that is supposed to give a better R value and and waterproof.

As well with the foam, vapor barrier and reflective foil, with the gap could a small fan installed to pull air our of the gap help? Since it is good to have an air space for moisture control.

Great website as well for Richard Kollmann, thanks!

I am aware that I need to plug the hole in the bottom of my box, as well I found a big hole where the wires and tubing leave to go the to condenser that I have to plug.

I will do the moisture tests and check with a small camera to see how much insulation is there.

Great, Great information here, I would have probably got some cans of foam figured it was fixed and got to the Caribbean and wonder why my fridge is always running.

I also understand there is alot of people who hang towels down the side of their boat over the area that they have their fridge to help,


Mark

[lancelots]

Hi Mark,
Without seeing the pictures of the cavity it is hard to say if a fan would help, if the cavity only has a small opening possibly. But now you would be adding the current draw of the fan (although the small computer type is all you may need) to the equation.


Check there are no other heat sources effecting your box, then start with the simplest cheapest fix you can. A light weight frame with some foil may be all you need to block the heat from hitting the box. Make the frame so it fits tight at the sides to block leakage perhaps with some soft spongy self adhesive tape, if you need a better heat barrier add some insulation to the side of the box I recommend the polyester batt with Velcro you can also get this in a blanket format which can be easily stitched together to double it up.


You now have a removable solution if it does not work to your expectations.

Good luck and
Kindest regards


Lancelots

[svmosaic38]

True, spray-in foam from the big box stores won't have much r-value. Most neighborhood refrigeration/airconditioning supply house have the correct foam, though the name escapes me. I'll call my refrigeration guy tomorrow and get back
Too much spraying of foam can result in putting alot of unnecessary pressure against the hull, bulkheads, etc. It's wise to spray any foams conservatively to keep expansion in check.

[Bill_E]

I've got a question about foam compositions. In post #19, Daddle noted "Neither polyurethane and polyisocyanurate are good with moisture over a period of time. They must be tightly sealed from exterior moisture." Both of these are hydrophobic materials (as is polystyrene) so why do they degrade over time in humid climates? I've got a friend who is a polymer engineer and I'll have to pose the question to him.

The way I see the problem is (as noted) we'd like to cut down all heat transfer: convective, conductive, and radiative. The foams are all designed to reduce convective transfer with a minimum of material touching to reduce the conduction. Water in the foam just increases the conductive transfer. By a lot! It's interesting that people are finding their old foam saturated with water. But, in most cases, this is an extreme insulation problem. You've got high humidity...in my case, very high humidity. The water temperature here in the tropics is always going to be a lot higher than the inside of your refrigerator so the heat leak from hull to the box is a problem. And probably the air temperature in the galley is pretty high. Then you've got vibration and flexing to worry about.

I realize that the exotic insulations are expensive, but so are new batteries and diesel fuel and charging systems. I don't think I can make a quantitative cost analysis but they look interesting. The question is: Will they stand up to the flexing and vibration from sailing into the wind for a few days?

[aboutgone]

I have a 1979 CSY 44 walk over. the stock reefer unit was huge (21cu/ft).
I have the SC-JS05 unit from global cooling, a great stand alone unit. At first I tried to retro fit the unit into my existing boxes.It worked great. but with 30 year old foam insulation and time on my hands, I tore out the old boxes and the old water soaked foam and started from scratch( it took two days). since the area was next to the engine room bulkhead, I spend the money for a vacuum panel to go against that bulkhead. The rest I used the pink board..the two boxes are now are 3.5 cu/ft each. the freezer side has 7 inches, the frig side has 5 inches of pink board. A frig a boat spill over fan handles the frig side. freezer side is 7 deg. frig side is 34 deg. ....well back to the thread.....my boxes are suspended from the counter top sitting on the hull on 1/2 milk crates ....so there is an air gap completely around them.....not like the old installation where the foam was filling the void all the way to the hull.......Ed

[skipgundlach]

Originally Posted by Bill_E

(clip hydro discussion)

I realize that the exotic insulations are expensive, but so are new batteries and diesel fuel and charging systems. I don't think I can make a quantitative cost analysis but they look interesting. The question is: Will they stand up to the flexing and vibration from sailing into the wind for a few days?

IMHO, from experience of survival of 3-5000 (based on the length of the storm and wave period for the 3 days Flying Pig banged on the rock at 60* heel) impacts during our wreck, a properly constructed box will take it easily.

While we were perched on the sides of the cabinets, talking to the USCG, we watched the entire floor (and cabinets on it) heave inches at a time as it crashed down. Further aft, the engine was doing the same thing as I peeked in the ER door to assess water intake. I was convinced our enormous reefer project was toast. I wasn't very happy about the tanks under the same sole, either, being FRP.

After it was all over, the reefer came out just fine, and the tanks had isolated small gelcoat separations.

So, I'd say yes, if you use extruded polystyrene. On the various hard stuff insulation, iso and urethathane have a higher R but are very weak on water repulsion; ExPoly is very strong (but I still covered it in epoxy). I had direct conversations with Kollmann on the subject. The difficulty of adequately (absolute security, and, how was I going to hang my shelving and evaporator if I had to drill???) wrapping the iso was why I didn't use it.

Totally OT, our also newly-installed PVC head plumbing survived intact, a REALLY good recommendation for that project if you have the ability. I can start a new thread if there is interest in knowing how we did it, but there is NO hose in our aft head, and only a couple of short connectors in the forward head...

L8R

Skip

[joefindaway]

I've been trying to get in touch with Global Cooling to order a SC-JS05... I'm not getting an answer from jewards nor the company itself? Ideas anyone? Thanks.

[nickhallam]

Hi Fawcettm -

Mark: have you talked to Bénéteau themselves about your fridge insulation? I'd be surprised if there was very much wrong with what they built in the first place, especially as they're French and sell huge numbers of boats for the Mediterranean. Filling in the air gap between the outer face of the fridge box and the hull is not simple, as you must take into account the inevitable movement of the hull under seagoing conditions. If your 'new' insulation is too rigid and too well bonded to hull and fridge box, you may damage the interior mouldings as the hull presses it out of shape. More likely is that the constant flexing will crush your new foam into dust over a short time. Do many other Bénéteau owners complain of poor fridge performance?

Nick Hallam