Super Maramu refrigeration insulation


michael winand
 

Hi, I am interested to know if anyone has re insulated their settee freezer, I feel that the original foam insulated box is not performing much
. I have not done a test on heat transfer, but feel that it could be improved. 
 I would like opinions on what you have fitted to your one and if you are happy with this improvement?
I am looking to upgrade my ones with CRYOGEL, 
This comes in 10mm thick sheet rolls and should be able to achieve r30 to r40 around the boxes.  
One of these jobs that would be comparable to a new hull bottom job, I think !!
Michael Nebo sm251 


Bill Kinney
 

Michael,

The Amel original insulation is marginal at best, pretty much ANYTHING you do will be better. We rebuilt one of our settee freezers from scratch and used Panasonic vacuum panels.  The end result was the single greatest thing we have done to reduce our power consumption on Harmonie.  Down about 50% on that freezer, about 20% on our overall power draw, and no more warm corners inside the box. Just as important to the improvement was the proper double gasket seal on the lid.  The amount of ice we accumulate on the evaporator panel has decreased drastically.

The Panasonic U-Vacua panels are a bit complicated to work with, since they come in a limited selection of sizes, but were surprisingly low in cost.  I needed to design and build a complete new box to accommodate them.  Ended up not 100% vacuum insulated, but very close.  A big project, but we ended up with a significantly larger interior volume, and a better performing freezer.  

I had looked at aerogel, but ended up with the vacuum panels because they were lower cost per square foot of box at the same R-value, and I just had to put more time and brainpower in to the design of the box to accommodate them. Other people's decisions might be in a different place on that balance.

Don't count on disassembling the existing box, removing insulation and putting it back.  It was not made to come apart. Also, adding insulation, even really good insulation, to the outside of the existing box won't help all that much. At least in our case, after 25 years of nearly constant use, the existing poured foam was quite saturated with condensed water.

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten


Michael Winand
 

Thanks Bill,
 I will have to see what is available in Australia.  Vacuum panels are much cheaper than the high tech blankets. I was concerned about how durable the vacuum panels are. I also have to buy a roll of the cryogel and would have half a roll left. 

It would be great to make the freezer efficient, I think it would use half the energy once properly insulated. 
Michael Nebo sm251 


On Sun, 8 May 2022, 11:57 pm Bill Kinney, <cruisingconsulting@...> wrote:
Michael,

The Amel original insulation is marginal at best, pretty much ANYTHING you do will be better. We rebuilt one of our settee freezers from scratch and used Panasonic vacuum panels.  The end result was the single greatest thing we have done to reduce our power consumption on Harmonie.  Down about 50% on that freezer, about 20% on our overall power draw, and no more warm corners inside the box. Just as important to the improvement was the proper double gasket seal on the lid.  The amount of ice we accumulate on the evaporator panel has decreased drastically.

The Panasonic U-Vacua panels are a bit complicated to work with, since they come in a limited selection of sizes, but were surprisingly low in cost.  I needed to design and build a complete new box to accommodate them.  Ended up not 100% vacuum insulated, but very close.  A big project, but we ended up with a significantly larger interior volume, and a better performing freezer.  

I had looked at aerogel, but ended up with the vacuum panels because they were lower cost per square foot of box at the same R-value, and I just had to put more time and brainpower in to the design of the box to accommodate them. Other people's decisions might be in a different place on that balance.

Don't count on disassembling the existing box, removing insulation and putting it back.  It was not made to come apart. Also, adding insulation, even really good insulation, to the outside of the existing box won't help all that much. At least in our case, after 25 years of nearly constant use, the existing poured foam was quite saturated with condensed water.

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten


Bill Kinney
 

Michael,

After much consideration, I decided that the majority of issues people had with vacuum panels was the result of poor installation.  The Panasonic panels are being sold as high performance building insulation, and the specifications list a minimum performance after 12 years. That seemed log enough for me...  When I designed the box I used two 0.5" panels instead of one 1" panel whenever possible so if one failed I'd still have a back up.

We ordered about 15 separate panels for the project.  One of those came DOA, and was quickly replaced by the supplier. What quickly became obvious is that fussy design is important.  The insulation capability of the panels is so high that the majority of the thermal leakage in the new fridge is AROUND the panels not through them.  Careful attention to minimizing conduction loses and being sure seals are air tight will very much pay off in reducing power usage even further.

After almost a year of operation, I am really happy.  Check back in a decade to see if that holds...

As an aside, close to 40 years ago I saw some of the first commercial production samples of aerogel. It's truly amazing stuff...  

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten


James Alton
 

Bill,

   What a great upgrade to any boat,  especially one that is not dockside and needs to produce it's own power.  I am curious about how to dealt with the gaps and joints at the edges of the panels?  So if these panels are being used as building panels does that mean that holes cut be cut to run the refrigerant tubing and such or did you work those in between a set of panels.  A brilliant move going with the 1/2" panels to reduce the chance of losing all of the vacuum insulation in an area of the box.  

James Alton
SV Sueno
Seagull Bay,  Turkey


-----Original Message-----
From: Bill Kinney <cruisingconsulting@...>
To: main@AmelYachtOwners.groups.io
Sent: Mon, May 9, 2022 5:15 am
Subject: Re: [AmelYachtOwners] Super Maramu refrigeration insulation

Michael,

After much consideration, I decided that the majority of issues people had with vacuum panels was the result of poor installation.  The Panasonic panels are being sold as high performance building insulation, and the specifications list a minimum performance after 12 years. That seemed log enough for me...  When I designed the box I used two 0.5" panels instead of one 1" panel whenever possible so if one failed I'd still have a back up.

We ordered about 15 separate panels for the project.  One of those came DOA, and was quickly replaced by the supplier. What quickly became obvious is that fussy design is important.  The insulation capability of the panels is so high that the majority of the thermal leakage in the new fridge is AROUND the panels not through them.  Careful attention to minimizing conduction loses and being sure seals are air tight will very much pay off in reducing power usage even further.

After almost a year of operation, I am really happy.  Check back in a decade to see if that holds...

As an aside, close to 40 years ago I saw some of the first commercial production samples of aerogel. It's truly amazing stuff...  

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten


Bill Kinney
 

James,

You can not cut the panels in any way, that was what made the design challenging. If the outer skin is punctured and the vacuum compromised, the remaining insulation capability is roughly equal to the same thickness of foam. At one time there were people who made custom sized panels, but those were expensive, and I wasn't able to find anyone still in that business.

The new box itself was made out of 4mm plywood with butt joints reinforced by epoxy fillets.  It's a simple technique that makes a surprisingly strong and rigid structure. All the wood was sealed with multiple coats of epoxy to make it (hopefully!) impervious to air and water vapor.

The insulating panels themselves I wrapped in the kind of 1/4" foam sheet used under the wood sill that sits on a building's foundation. This protected the surface of the panels from any mechanical damage, gave a little bit of "squish" to the fit, and also helped eliminate gaps where air could flow.

There were a few places in the design I couldn't close up with the fixed size panels that were available. Those were insulated with 4" of high quality foam sheet, any remaining gaps were filled with spray foam. It was one of the foam insulated places where the tubing and wires penetrate the wall.  I epoxied in a PVC pipe as a conduit to keep the insulation compartment air tight, and then filled that with spray foam after connecting everything.

I did everything I could think of to keep outside air from migrating into the insulation to avoid water condensation in the insulation.

The whole thing was painted with polyurethane paint to match the Amel interior gelcoat.

If I was doing it over, I'd probably use thinner plywood for the interior lining.  Conduction along the wood seems to be the biggest heat gain.  I am sure that there is some thin, stiff, tough honeycomb engineered material out there that would be even better, but I did not find any thin enough I was sure would work. Maybe a deeper dive into material for the aviation market would find something.

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten


Andrew Wilson
 

Hi Amelians,

Oliver on SV Vela Nautica made a couple of YouTube videos on his project to re-build his main freezer on his A54, he used custom made/sized panels:




Cheers

Andrew Wilson
Future Amel Owner
Wellington, NZ


From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> on behalf of Bill Kinney <cruisingconsulting@...>
Sent: Tuesday, 10 May 2022 2:39 pm
To: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io>
Subject: Re: [AmelYachtOwners] Super Maramu refrigeration insulation
 
James,

You can not cut the panels in any way, that was what made the design challenging. If the outer skin is punctured and the vacuum compromised, the remaining insulation capability is roughly equal to the same thickness of foam. At one time there were people who made custom sized panels, but those were expensive, and I wasn't able to find anyone still in that business.

The new box itself was made out of 4mm plywood with butt joints reinforced by epoxy fillets.  It's a simple technique that makes a surprisingly strong and rigid structure. All the wood was sealed with multiple coats of epoxy to make it (hopefully!) impervious to air and water vapor.

The insulating panels themselves I wrapped in the kind of 1/4" foam sheet used under the wood sill that sits on a building's foundation. This protected the surface of the panels from any mechanical damage, gave a little bit of "squish" to the fit, and also helped eliminate gaps where air could flow.

There were a few places in the design I couldn't close up with the fixed size panels that were available. Those were insulated with 4" of high quality foam sheet, any remaining gaps were filled with spray foam. It was one of the foam insulated places where the tubing and wires penetrate the wall.  I epoxied in a PVC pipe as a conduit to keep the insulation compartment air tight, and then filled that with spray foam after connecting everything.

I did everything I could think of to keep outside air from migrating into the insulation to avoid water condensation in the insulation.

The whole thing was painted with polyurethane paint to match the Amel interior gelcoat.

If I was doing it over, I'd probably use thinner plywood for the interior lining.  Conduction along the wood seems to be the biggest heat gain.  I am sure that there is some thin, stiff, tough honeycomb engineered material out there that would be even better, but I did not find any thin enough I was sure would work. Maybe a deeper dive into material for the aviation market would find something.

Bill Kinney
SM160, Harmonie
Simpson Bay, Sint Maarten