Aerogel - Spaceloft Insulation for Fridge / Freezer

[magentawave]

bartonman - Hey thanks for finally responding cuz that is all great stuff to know!

[bartonman]

Your welcome. It is truly the best insulation.

I like the potential it has when used in VIP's, but they are still fragile and the vacuum degrades over time. I don't like the idea of insulation with an expiration date. Especially when it is usually built-in and a bear to tear out and replace.

I am working on a design for inexpensive custom cut VIP's using Spaceloft as the core material and trying to get the life span closer to the 100 year mark.

Of course I will let the Cruiser Community know if we are successful. The feedback from such a diverse and resourceful group is really productive.

[morays]

Can anyone tell me what you can use to attach Spaceloft to vertical surfaces such as fiberglass, paint or a moisture barrier. My reefer rebuild is underway and I have removed the old one as well as the old foam insulation from under the galley countertop. I am currently glassing in a framework to allow a small air gap between the hull and the insulation to allow condensation to run down into the bilge.
I will Bilgekote the other three walls and want to seal the Spaceloft layers to the Bilgekote surface as well as itself for subsequent layers.
Once I have enough insulation layered (looking at 3" to get an R value of over 30), I will build a frame to support the FRP sheets, from R parts, that will make up the box itself.
Any help with the appropriate sealant or comments on my build process would be greatly appreciated

Moray Sandison
s/v/ Sol Purpose
http://solpurpose.wordpress.com

[robert sailor]

Originally Posted by morays

Can anyone tell me what you can use to attach Spaceloft to vertical surfaces such as fiberglass, paint or a moisture barrier. My reefer rebuild is underway and I have removed the old one as well as the old foam insulation from under the galley countertop. I am currently glassing in a framework to allow a small air gap between the hull and the insulation to allow condensation to run down into the bilge.
I will Bilgekote the other three walls and want to seal the Spaceloft layers to the Bilgekote surface as well as itself for subsequent layers.
Once I have enough insulation layered (looking at 3" to get an R value of over 30), I will build a frame to support the FRP sheets, from R parts, that will make up the box itself.
Any help with the appropriate sealant or comments on my build process would be greatly appreciated

Moray Sandison
s/v/ Sol Purpose
http://solpurpose.wordpress.com

On mine I built it with an inner and outer box with the Aerogel in between carefully cut and each layer staggered where they met in the corners. Used foil and a vapor barrier as well. Results have been better than expected.

[Steadman Uhlich]

An interesting short video (2 minutes) on Aerogel, hosted by a scientist from Lawrence Livermore National Laboratory.

One very impressive demonstration shows a relatively thin layer of aerogel protecting the naked open hand of the scientist from a blow torch! Seen at 1:21 in the video.

http://www.youtube.com/watch?v=kHnen2nSmDY

[bartonman]

Originally Posted by morays

Can anyone tell me what you can use to attach Spaceloft to vertical surfaces such as fiberglass, paint or a moisture barrier. My reefer rebuild is underway and I have removed the old one as well as the old foam insulation from under the galley countertop. I am currently glassing in a framework to allow a small air gap between the hull and the insulation to allow condensation to run down into the bilge.
I will Bilgekote the other three walls and want to seal the Spaceloft layers to the Bilgekote surface as well as itself for subsequent layers.
Once I have enough insulation layered (looking at 3" to get an R value of over 30), I will build a frame to support the FRP sheets, from R parts, that will make up the box itself.
Any help with the appropriate sealant or comments on my build process would be greatly appreciated

Moray Sandison
s/v/ Sol Purpose
http://solpurpose.wordpress.com

Hello Moray,
I like Roberts idea of making an Aerogel sandwich. Mylar makes a great vapor barrier and isolates the dust from the aerogel. I've successfully used 3M Super 77 Spray Adhesive to attach Spaceloft Aerogel to substrates. You definitely chose the right product. Good luck.

[senormechanico]

I also used 3M 77 in my fridge/freezer build.
When I reinsulated the boat's hot water tank, I spiral wound it with aerogel, spraying the adhesive as I applied the insulation.

[YachtManuals]

I used strong spray contact-adhesive for outside of aerogel sheets, as well as in between, and then insides to the FRP panels. Having an air gap against the hull is OK but there needs to be a completely sealed outer case to the insulation with a vapour barrier (such as mylar or alu foil, sealed with similar tape along all edges); a bit tricky as you are working from the "wrong" side. Also make sure any penetrations (for tubes and wires) are perfectly sealed from the aerogel. It not as important that there is a perfect seal along the tubes between the outside and inside of the finished fridge. Even FRP panels do not seal forever against moisture on the fridge floor where water tends to stand permanently (unless you make a drain pipe). I applied a 1/2" white self-levelling epoxy pour on the floor for additional moisture barrier, which leaves a very shiny easy to clean surface, and stiffens it, even though I had first doubled the FRP. Also bear in mind that all the weight of the fridge or freezer contents will rest on the floor and potentially weigh it down, compressing the aerogel. For me, the floor is really supported by the sides, which are attached to the edges of the fridge top opening; you don't want any cracks developing here in the future, so I used glassfibre tape and epoxy resin to join everything. Any shelf supports were glued on at the end. Screws for attaching the evaporator plate go into glued-on blind distance pieces, i.e. no screws penetrating into the insulation.

[Lars_L]

One of the problems with doing a freezer with VIP panels is that the joints have such poor insulation that there will be ice on the outside. To avoid this, I construct two boxes within each other, have a distasmaterial (e.g. Aerogel) in the gap and then sucks vacuum in the gap. Then I get a VIB vacuum insulated box. A cooling companies that install commercial cooling has a vacuum pump that can handle this pressure (< 5 Pa).

Another problem with VIP is the barrier. It is made of a lamminat consisting of different plastics and aluminum foils. It is cheaper than stainless steel but more fragile for small holes and not as dense. In a freezer there is quite small areas, so these do not affect the price so much.

I have made drawings on a freeze to my boat.
The freeze have an interior volume of 100 litres.
The surface area A = 2.0 m²
It have a wall thickness t = 50 mm = 0.05 m
The insulation have a lambda value λ = 45 mW/Km
Then the u-value will be u = λ / t = 45 mW/Km / 0.05 m ≈ 0.1 W/Km²
Ambient temperature Tr = 30 °C
Freezer temperature = Tf = -20 °C
Temperature difference dT = Tr – Tf = 30 °C - -20 °C = 50 °C = 50 K
Together the power leak will be P = λ * dT * A = 0.1 W/Km² * 50 K * 2.0 m² = 10 W

A well-built water-cooled compressor takes about 12 W when it gives 10 W cool. That means 1 A. Day around. It is what you would expect to get from a 100 W solar panel.

[morays]

@YachtManuals - can you please tell me the make and model of a good self leveling white epoxy that I could use for the seal on the bottom?

[Roy M]

West System Resin with white pigment. It will stay white longer if you use white LPU paint as a topcoat, because, eventually, UV light gets to the straight epoxy and begins to yellow the finish. This is the interior of my box, before the top went on. I used vacuum insulated panels instead of Aerogel, but to each one's own. Click on the image to enlarge.

[morays]

Originally Posted by Weyalan

Our cold plate is mounted in against an interior wall in the freeze. Well, against 3 walls, to be precise. We (carefully) bent the flat panel to fit along 3 sides of the freezer box, with about 10mm (3/8") air gap between the panel and the box and then fitted a perforated plate to protect the cold plate, agai with about a 10mm (3/8") air gap. You can see the peforated plate in the photo below:


No defrosting required yet, but it is still early days, I guess.

Weyalan,

Can you please tell me where you got your perforated plate that you covered your evaporator with?

[YachtManuals]

Originally Posted by morays

@YachtManuals - can you please tell me the make and model of a good self leveling white epoxy that I could use for the seal on the bottom?

Sorry, I don't have that info with me right now. It was a clear epoxy resin thin enough to self-level, that I tinted with white with titanium oxide thick liquid made for tinting resins. I did not want to paint the inside as it will eventually peel a little.

The evaporator plate was covered with a removable, perforated plastic, sold as a basin liner in stores. This is easy to remove and clean, plus it acts as a bumper for food containers (see photo). PS: Sorry the photo doesn't seem to up-load.

[overtheseas]

Couldn't find the Glacier Bay site but this one works
Pacific Sea Breeze Marine Products - Ultra-R Vacuum Insulation

[Weyalan]

Originally Posted by morays

Weyalan,

Can you please tell me where you got your perforated plate that you covered your evaporator with?

Sure, but I'm not confident it will help you much. It was "The Perforated & Expanded Metal Company" In Hobart, Tasmania, Australia, lol.

Seriously though, if you do a google search for performated metal in your area, you should be able to get hold of some easy enough. The only problem is whether you will be able to get what you want without having to buy an 8' x 4' sheet, heh

The stuff that we got was aluminium and probably about 50% metal, 50% hole, I guess, maybe 1.2mm (3/64") thick, but pretty much anything will do... we just wanted to try to make sure we protect the expensive and relatively fragile cold plate from accidental contact with heavy or sharp objects.