Aerogel vs polyiiso...$ vs Space

[SV THIRD DAY]

Aerogel is great stuff...the only problem is $$.
for a 1" thick comparison:
Polyisocyanurate: R-value is 6.5 and cost is $0.63/square foot
Aerogel: R-value is 10.3 and cost is $46/square foot.

So if you want to have an R30 insulated Box, you would need 3" of Aerogel or 4.6" (round it up to 5") of Polyiso. I haven't done the math on what it would cost to insulate an 8 Cubic foot box with 3" of Aerogel and compare that to polyiso, but if you have the space for 5" of polyiso you could save a LOT of coconuts.

The one square foot price difference between 3" of Aerogel to 5" of Polyiso is like $172.5 to $3.13. Now it's early and my math brain maybe hasn't woken up yet, but I'm using the Ebay price of Aerogel at $23 per square foot for a 10mm (0.4") piece compared to the Home Depot price of polyiso at $20 for 32 square foot sheet (4ft x 8ft 1inch thick). Am I smoking crack...or are those cost numbers about right....yawza...

Another way to look at it on a $/R-value:
PolyIso $0.10
Aerogel $5.63
(used $172.5 for R30.6 for Aerogel and $3.13 for R32 for Polyiso)
That is a 56 Times higher cost...Aye Crumba...

Now of course there are other benefits to Aerogel other than R-value, but you can never really take COST out of the equation or you end up debating how many angles will dance on the head of a pin because normal people couldn't afford it anyway.

Thoughts?
What have others found working with Aerogel in terms of cost per R-value.

Unless someone just doesn't have the space, my preferred recommendation for someone redoing their Box insulation would still be Polyiso based on the cost differential.

[jamhass]

Rich

The cost of the insulation goes as the volume of the insulation, not the thickness. Thus, a notional 8 cubic foot refer, with 3 inches of A uses roughly 3.4 cubic feet of Ag. 5 inches of PC ends up using 6.1 cubic feet of PC.

By your numbers, Ag at 23 for 0.4 inches is 690 per ft3, PC at 5.63 for 1 inch is 68 per ft3.

Thus, AG cost roughly 2350, PC about 415.

[ColdEH]

I agree , crazy money for the stuff , hard to work with as well . I just used it on my two to doors and had to cut the stuff with my table saw , be careful if anyone chooses to do the same , it can grad the blade .
The rest of the box is 5 inches of polyiso with the first layer on the cold side being blueboard foam , so 6" all the way around . Maybe eight on the bottom . I lost count of the layers I was building it up so the wife could reach all the way down . Used the Areogell in the lids to keep them as thin as possible . I would have never considered doing the whole box in the stuff . To many dollars for a small gain .

Regards




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[SV THIRD DAY]

Originally Posted by jamhass

Rich

The cost of the insulation goes as the volume of the insulation, not the thickness. Thus, a notional 8 cubic foot refer, with 3 inches of A uses roughly 3.4 cubic feet of Ag. 5 inches of PC ends up using 6.1 cubic feet of PC.

By your numbers, Ag at 23 for 0.4 inches is 690 per ft3, PC at 5.63 for 1 inch is 68 per ft3.

Thus, AG cost roughly 2350, PC about 415.

Thanks for doing some math I didn't have the energy to do this morning...ha ha ha
I was just working with how the insulation is priced and sold online which is per square foot to help keep the math easy to follow.
10mm (0.4") thickness of Aerogel at $23 and
$20 for a 1" 32 square foot sheet of polyiso.

$2350 vs $415....hmmm....that two months worth of Cruising Kitty budget for me!

[ColdEH]

This was what was in my old fridge doors .

Regards


Sent from my iPhone using Cruisers Sailing Forum

[SV THIRD DAY]

Originally Posted by typhoon

This was what was in my old fridge doors .

You and 90% of the cruising boats out there...ha ha ha

[ColdEH]

Originally Posted by SV THIRD DAY

You and 90% of the cruising boats out there...ha ha ha

I wonder if custom builders like Lyman morse or Morris yacht build a better fridge . Knowing what they know to build a yacht and what they charge for one of there creations you would think they would . It would be an interesting conversation .

Regards


Sent from my iPhone using Cruisers Sailing Forum

[ErikFinn]

USD 2350 for aerogel material only to insulate an 8cf (227l) box to R30??

[newhaul]

Originally Posted by SV THIRD DAY

Thanks for doing some math I didn't have the energy to do this morning...ha ha ha
I was just working with how the insulation is priced and sold online which is per square foot to help keep the math easy to follow.
10mm (0.4") thickness of Aerogel at $23 and
$20 for a 1" 32 square foot sheet of polyiso.

$2350 vs $415....hmmm....that two months worth of Cruising Kitty budget for me!

At the cost of aerogel I would rather add another couple hundred watts solar and or another holding plate.

[crazyoldboatguy]

I will have the room to use the lesser cost insulation as opposed to the aerogel - although using it for the top to reduce lid thickness makes sense.

Then Insaw this. Thermal degradation of urethane modified polyisocyanurate foams based on aliphatic and aromatic polyester polyol

Now I am wondering about polyiso. Seems there are problems with the insulation properties AND it seems to degrade over time.

What's a sailor to do?

[nautitrix]

I agree that aerogel as a first layer is advantageous. But not just for cost, the closer you get to 0c. 32f. The less effective the poly-iso is. Poly-iso is best used with something separating it from the cold side other wise you are paying for insulating value you are not getting. This is especially true for a freezer where a 1/2 inch layer of high density styro between the cold side and the poly-iso would save money and extend the insulating value. Using Aerogel at 2 1/2 grand for a boat freezer you would have to calculate the running cost of the reefer and the value of lost food to see if it is economical. I like the idea of using it on the top and doors at least. I am really hoping that the cost of Aerogel will eventually come down.

[ColdEH]

Originally Posted by nautitrix

I agree that aerogel as a first layer is advantageous. But not just for cost, the closer you get to 0c. 32f. The less effective the poly-iso is. Poly-iso is best used with something separating it from the cold side other wise you are paying for insulating value you are not getting. This is especially true for a freezer where a 1/2 inch layer of high density styro between the cold side and the poly-iso would save money and extend the insulating value. Using Aerogel at 2 1/2 grand for a boat freezer you would have to calculate the running cost of the reefer and the value of lost food to see if it is economical. I like the idea of using it on the top and doors at least. I am really hoping that the cost of Aerogel will eventually come down.

Yes I read the same thing about poly-Iso and the cold . I put a layer of blue board on the cold side just in case this holds any truth . Seems to work just fine . To test the difference would be a very hard thing to do .

Regards

[SV THIRD DAY]

Originally Posted by crazyoldboatguy

I will have the room to use the lesser cost insulation as opposed to the aerogel - although using it for the top to reduce lid thickness makes sense.

Then Insaw this. Thermal degradation of urethane modified polyisocyanurate foams based on aliphatic and aromatic polyester polyol

Now I am wondering about polyiso. Seems there are problems with the insulation properties AND it seems to degrade over time.

What's a sailor to do?

What's a Sailor to do?

Easy....go Cruising because that linked article has nothing to do with Polyiso's real world application, that wasn't even the point of the Research Paper. Here is the Paper's abstract because this is how Internet Chat room myths and rumors are hatched.....

Abstract

Combustion of polyurethane foams releases toxic gaseous products. Therefore, decreasing the flammability of polyurethane foams is of practical significance to public health and the environment. The reported study investigated the thermal stability of urethane modified polyisocyanurate foams based on the presence of aromatic, aliphatic polyester polyol and polyether polyol moieties. Thermogravimetric analysis and differential scanning calorimetry demonstrated that the foam containing the lowest isocyanate index (220) and the lowest molecular mass of polyether polyol (200) was the most flammable (35% of char residue). Furthermore, the foams which contained a high molecular mass of polyether polyol (2000) and high isocyanate index (460) experienced fire performance (45% of char residue) similar to those foams containing aliphatic and aromatic polyester polyol (41 and 44% of char residue respectively).

[jamhass]

(Un??)fortunately, insulation is only one of the variables in refer design, and we can often take advantage of these other variables to optimize the design, minimize cost and/or reduce operating "budget" (i.e. amp-hours AH.)

For example:

A surprising amount of refer load comes from the hull, especially in sunny warm places like down here in the Sea of Cortez. A simple sun shield hung on the outside of the hull on sunny day can be remarkably effective. Similarly, one can/should add some extra insulation on the hull side when designing new or refitting.

Slight air leaks around the seals of the refer cost a lot of AH. On our top-loader, we use a yoga mat. It reduces the air leak and heat load, and provides a non-skid surface (for the cat ... another story) We know it is effective because condensation does accumulate on the bottom of the mat (fortunately, not on the cat)

We found our freezer to be larger than we really use. And that space is costly in terms of AH. We found 2 things that help. 1. We simply put additional layers of rigid insulation on the bottom of the freezer (not "installed", just placed there like a slab of meat. It adds insulation and reduces the volume to be cooled. Easily replaced, but lasts surprisingly long. 2. We put water bottles (not quite full) in the freezer when there is unused space. Freezing these (especially when hooked to shore power) adds thermal mass and reduces cycling of the freezer.

Just a couple of random thoughts ...

[Waterrat10]

What about Vacuum insulated panels?