Building a Reefer Box with Aerogel

[s/v Jedi]

Originally Posted by bluesphere

Richard,
Thanks for the reply. I need all the help I can get. Im in Panama refitting for my 2nd Pacifoc crossing and it's difficult to get supplies here. My wife is going to the states in March and going to pick up the insulation.

Im thinking to put a moisture barrier between the box and insulation as well as in between each layer.

Any other ideas?

Sail far and live slow.

Alex

Marine Warehouse can get you anything in Panama.

[magentawave]

Hey guys, sorry if this has already been covered but I was wondering if eBay is the cheapest source in the US for buying this stuff?

And which is the best material to use for a fridge box - Cryogel, Cryogel Z, or Spaceloft?

Thanks

[Erasmuss]

Based on My knowledge of Aerogel and the Specifications of their different Materials I believe the basic Cryogel ( Not the Z ) would be the best material of them all.

My reasoning - it is the Lightest of all their materials at 8 Lbs/ Cubic Foot.

Also if you look at Cryogels recovery after compression it has the highest load capacity at 250 PSI.

Between these two characteristics - Best Compression Recovery and Lightest Weight - and at the relatively low temperatures we are speaking of - Neither Super Hot or Cold - I think Cryogel is the Call.

One of the reasons that Aerogels are so effective is that they are mostly air. The best Experimental Aerogels - at insulating - are nearly if not lighter than air. The Materials in discussion are what is commercially available (and at a reasonable price ) at this time but don't really meet the full promise of what these types of materials may provide or show promise of in the future. Although the truly exotic stuff is available at exorbitant cost and not practical - or available to the average Joe - at this time.

My Two Cents. Ultimately this is a simple observation on my part and if you could actually get a real product engineer ( Not a Salesman or as they are referred to, a Sales Engineer ) on the phone from Aspen Aerogels then I am sure they would be the best source for your answer.

Their Phone Number is 508.691.1111

Sincerely,
Erasmuss

[GordMay]

Greetings and welcome aboard the CF, Erasmuss.

[Emerald Sea]

Ask and talk with Mario at Aerogel, he is quite technical and should be able to assist. We use their products for deep water high temp pipelines (pipe in pipe) and they are effectively the market leader in insulation technology. I've been in pipeline design for many years, used a few similar products, but we return to Aerogel. I'm sure you can find a good thermally conductive and thin (compressed) blanket for your fridge.

Steve
SV Emerald Sea
L450


Emerald Sea
Lagoon 450/304

[biker6977]

I am wondering if this is possible to eliminate the the condensation issue- can you put on the Aerogel and then to a "vac bag" system over it? Maybe use visqueen to size, suck as much air out as possible then seal it shut. Would this negate the insulation properties by removing the air? Just trying to think of a way to negate the condensation issue while being able to use the best possible insulation......

[Terra Nova]

Condensation can be a problem if the door seals are faulty.

[rgleason]

I have one comment about the morgan build. Using reflective insulation without having an air space of 1/2" will be ineffective, as insulation, to reflect heat, however it may help with moisture.

[GordMay]

Originally Posted by rgleason

I have one comment about the morgan build. Using reflective insulation without having an air space of 1/2" will be ineffective, as insulation, to reflect heat, however it may help with moisture.

Indeed!

With reflective foil insulation [a low emittance surface radiant barrier], it's generally recommended to leave an air gap [void, without free air flow] of at least 1/2 inch* [12mm], or more*, between the foil layer, and the surface it's installed on. This allows the foil to reflect radiant heat, rather than absorbing or conducting it.

At the point where materials [foil & wall] are touching, the primary mode of heat transfer, between them, stops being radiative, and instead becomes conductive. Conduction is an effective means of transferring thermal energy, and so to prevent it, the materials must have an air space between them.

However, a surface, that's not exposed to significant radiant heat [sunlight, engine, hot water line, etc], will NOT BENEFIT from a radiant barrier.


* Air Space Requirements:
‘Reflectix’ ➥ https://cdn.reflectixinc.com/wp-cont...s-Rev-0219.pdf
Covertech ‘rFOIL’ ➥ https://rfoil.com/media/R-Value-Appl...eb-2018-1f.pdf

[rgleason]

Thanks GordMay for the authoritative confirmation.
One example I can think of for use of reflective with air barrier, along the hull is the case of a black hull in full sun, with the box alongside it.

[s/v Jedi]

The question of course is if foam can be the air barrier. The insulation properties of foam are based on it being mostly captured air to prevent convection.

[GordMay]

Originally Posted by s/v Jedi

The question of course is if foam can be the air barrier. The insulation properties of foam are based on it being mostly captured air to prevent convection.

No - it cannot.

[s/v Jedi]

Originally Posted by GordMay

No - it cannot.

Any logic or citations to support that? I could find data showing that foam has an air gap equivalent insulation rating…

[GordMay]

Originally Posted by s/v Jedi

Any logic or citations to support that? …

It's very common [non-controversial] knowledge, in the [HVAC, insulation, building envelope] industry.

Radiant Barriers ~ U.S. Dept. Of Energy
➥ https://www.energy.gov/energysaver/radiant-barriers

The importance of air space in radiant barrier applications ~ EcoFoil
➥https://www.ecofoil.com/pages/how-do...t-barrier-work

Radiant Barrier Fundamentals ~ Green Building Advisor (GBA)
➥ https://www.greenbuildingadvisor.com...r-fundamentals

[s/v Jedi]

Originally Posted by GordMay

It's very common [non-controversial] knowledge, in the [HVAC, insulation, building envelope] industry.

Radiant Barriers ~ U.S. Dept. Of Energy
➥ https://www.energy.gov/energysaver/radiant-barriers

The importance of air space in radiant barrier applications ~ EcoFoil
➥https://www.ecofoil.com/pages/how-do...t-barrier-work

Radiant Barrier Fundamentals ~ Green Building Advisor (GBA)
➥ https://www.greenbuildingadvisor.com...r-fundamentals

The air gap is not a radiant barrier. The air gap is a conduction barrier that supports the radiation barrier. Air that doesn’t move is a very efficient conduction barrier, but so is foam.

I may be missing some details so will study the links

Edit: ah, okay this is the air gap facing the radiation barrier. Yes, without it there will not be any radiation.

That said, you can have radiation transfer through unintended voids, especially on boats. So if you build a foam box to install in the galley, against the hull, cabinet etc. Tthen it is still a good idea to cover it with aluminum foil, shiny side out (as well as a moisture barrier that goes on first). Where this foil touches the hull, cabinet it’s useless, but when there is a void it will work.