Aerogel insulation for fridge

[Gerry]

We are installing a new fridge onboard. Looking at insulation we wondered if anyone has used Aerogel insulation on their boat? Does it really deliver the increased insulation that the manufacturers claim? It almost sounds too good to be true......

 

[alan]

Gerry, I have never tried it on my boat - but have been considering it. The company I work for use it for insulating electronic components which need to operate at very low physical temperatures. Prior to using Aerogel, we used to keep these components in a vacuum. This required the use of vacuum pumps and seals that need replacing regularly etc etc
Using Aerogel in place of the vacuum has improved peformance and is maintenance free. So, using Aerogel in place of "normal" insulation will be significantly more efficient. I am not sure about the cost but could easily find out if you need to know.

Alan.

 

[macd]

I added Aerogel sheet (3 x 10mm thickness) to our fridge last winter. It's wonderfully effective, although it ought to be at that price. If there's room to fit a greater thickness of good, conventional insulation (such as PIR), I'd suggest that's a better alternative (and certainly very much cheaper). Aerogel comes into its own when space is limited.

If installing Aerogel sheets, it's worth bearing in mind some odd characteristics. In it's initial state it's hygroscopic, but then treated to be hydrophobic. The medium for this seems to be a very, very fine powder. It gets everywhere, and renders everything like teflon unless carefully washed off -- tricky if you're trying to bond it, or apply aluminium tape to preserve a waterproof membrane. You can put your hands under a running tap and they come out bone-dry. Good party-trick, but not very helpful.

 

[Javelin]

Have built a couple of fridges using Aerogel and am halfway through building a 135lt one for a Hoek 51.
As Mac has stated above it has some very unique handling issues and the dust that comes off the sheets is a particular pain.

The two big bonuses are the fact that the sheets are very flexible so lining a odd shaped void is very easy and of course three layers of 10mm aerogel is the equivalent of using 50mm of celotex foam which saves a lot of space.

 

[Trident]

I used it to insulate my fridge last winter after a summer of very high current drain. The dust as mentioned is a pain and mask and gloves are needed but 20mm added all round meant I went from fridge on 30 minutes or so in every hour to on 6-8 minutes in every hour in the Med summer. Very effective and from eBay at least, reasonably priced (though not compared to polystyrene etc)

I did all the wrapping outside and then covered the lot with thick tin foil and sealed with aluminium tape just to keep the dust where it should be.

 

[macd]

then covered the lot with thick tin foil and sealed with aluminium tape just to keep the dust where it should be.

Reflective bubble-wrap, which is nothing great as an insulator, is especially good for that final wrap when adding external insulation: it's cheap, tough, and tape sticks to it well.

 

[Gerry]

Thank you for the hints and tips! Removal of the old unit is underway and we will definitely be going with the aerogel option as we install the new box. I am excited to see whether it will keep power useage as low as we hope and if we can cruise with a functioning fridge for the first time in years!