Aerogel

pmagowan

pmagowan

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I am sure some of you have heard about this insulation material which is currently supposed to be the best available. I am wondering if anyone has any experience of it, in what form and in what application. I was wondering if it could be used for hull insulation in a new-build and also in fridge/freezer insulation. The thing is that boats are small enough without putting in loads of insulation so obviously a more efficient insulation material will save space. I am thinking of this with regards to the design stage of a new-build and what layup needs to be done. The construction method will be cold moulded strip and veneer to make a monocoque hull. So the layup from outside to inside will be;
Paint
Epoxy glass fibre
3 layers of wood veneer and epoxy
cedar strips
Epoxy glass fibre

Can the insulation fit in here somewhere are is it best to attach it as an internal liner?
What about moisture?

Thanks
 
JumbleDuck said:
Silica aerogel is strongly hygroscopic and water soluble. Maybe not the best material for marine use.
Click to expand...

Yes but the manufacturers have addressed this and it is available in hydrophobic forms. Even so there is still the option of isolating it from moisture, which I would be concerned about with any insulating material.
 
pmagowan said:
I am sure some of you have heard about this insulation material which is currently supposed to be the best available. I am wondering if anyone has any experience of it, in what form and in what application.
Click to expand...
You won't be able to get hold of any at a reasonable price so I'd give up on it if I were you.

Boo2
 
Boo2 said:
You won't be able to get hold of any at a reasonable price so I'd give up on it if I were you.

Boo2
Click to expand...

It is being used in home insulation and is produced in large rolls for this function. I would therefore assume that the quantity required for a boat, along with the massively increased benefit in this application compared to home insulation, would make it within reason. I don't give up until I have all the information to compare, hence the question.
 
It is used in few boat fridges, close to the performance of vacumme panels without the gradual (and sometimes sudden) loss of performance.

I understood it was very expensive, but perhaps that has changed.
 
A lot of boats are built with foam of some sort in an FRP sandwich.
That is good thermally, but it's not as robust as your glass/wood/glass.
Equally end grain balsa can be used as a core and has a highish thermal resistivity, but can have problems if any moisture gets in.
Any core material seems to have limits where it breaks up and becomes detached from the skins, this is disastrous if it happens over a wide area, the panel loses a great deal of stiffness.
Find the R-values, do the math as they say.
 
lw395 said:
A lot of boats are built with foam of some sort in an FRP sandwich.
That is good thermally, but it's not as robust as your glass/wood/glass.
Equally end grain balsa can be used as a core and has a highish thermal resistivity, but can have problems if any moisture gets in.
Any core material seems to have limits where it breaks up and becomes detached from the skins, this is disastrous if it happens over a wide area, the panel loses a great deal of stiffness.
Find the R-values, do the math as they say.
Click to expand...

Thanks. The R values are blinking marvelous, more than 4 times as good as foam. The wood in my layup will have thermal properties but its prime importance is for its structural properties. I was thinking this boat might end up somewhere cold like the NW passage so I was trying to take this into account. I am also into insulation in general having recently added 8 inches of it to the outside of my house.
 
I would think you may reach a point of diminishing returns pretty quickly as IMHO any boat needs a fair amount of ventilation. Once the majority of heat loss is via air exchange, more/better insulation has little value.
Enough insulation to prevent excess condensation and keep heating requirements down would be my goal.

If you were to e.g. halve the amount of Eberbasto use for the time you own the boat, how much would that actually save?

From my experience with foam construction, I wouldn't be compromising the structure to save a bit on heating, you can feed the eber for a long time on the price of a small dent repair.
I would be looking at a separate thermal liner perhaps? Particularly under the deckhead.
 
lw395 said:
I would think you may reach a point of diminishing returns pretty quickly as IMHO any boat needs a fair amount of ventilation.
Click to expand...

Some aluminium boats have thick foam insulation. Mine has 75mm. It makes a significant difference to comfort inside especially in hot weather when compared to normal fibreglass construction (especially when the hull has no core).

Because of the stringers and framing in a metal boat the insulation costs very little interior room. A thin layer of Aerogel could be used on frameless boats like fibreglass to produce a similar effect without much penalty on the interior space.

I think it is a good idea if the costs have come down. As noted it does have incredible insulation properties.
 
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One thing I have also been thinking about is the ventilation. I see no reason why this has to be uncontrolled. If you had active ventilation through a heat recovery unit and the eberspacher then it would be highly thermally efficient and act as a dehumidifier. For all the size of a boat this could be achieved quite easily with a quite simple unit. The eberspacher already has a fan which could be used and an arduino could easily be programmed to control the system. Of course passive ventilation could be used as required but would invalidate the system until closed off again. There is potential to also use this in conjunction with CO and gas sensors as a safety mechanism, or to close off ventilation in the event of a fire. It is used in houses which are, by nature, more leaky than boats.
 
pmagowan said:
It is being used in home insulation and is produced in large rolls for this function. I would therefore assume that the quantity required for a boat, along with the massively increased benefit in this application compared to home insulation, would make it within reason. I don't give up until I have all the information to compare, hence the question.
Click to expand...
Where can you buy it, and at what price ? I tried to source some and failed, hence my point.

Boo2
 
lw395 said:
're-assuringly expensive?
I suggest building the boat a couple of inches wider to make space for PU foam.
Click to expand...

I am sure it can be got cheaper. That is a site for small quantities. I might try and work out what the price per cubic foot is for a yacht and then work out how many cubic feet this would save. Imagine its use in a fridge for instance, it would be 1 inch instead of 5. That is an amazing space saving. Just imagine a standard cold box and take 5 inches off each side to see how small it gets
 
pmagowan said:
I am sure it can be got cheaper. That is a site for small quantities. I might try and work out what the price per cubic foot is for a yacht and then work out how many cubic feet this would save. Imagine its use in a fridge for instance, it would be 1 inch instead of 5. That is an amazing space saving. Just imagine a standard cold box and take 5 inches off each side to see how small it gets
Click to expand...

Possibly worth it for a fridge as the temperature delta is a lot more, and the area is not so great.
But do the sums and you may find most of the heat transfer in a typical boat fridge is not going through several inches of PU foam.
 
Might it not be particularly good for internal lining of an existing coolbox (with suitable inner panelling of course)? Not the original interest, I realise.
 
Hydrozoan said:
Might it not be particularly good for internal lining of an existing coolbox (with suitable inner panelling of course)? Not the original interest, I realise.
Click to expand...

Well a fridge was one of the uses I was thinking of. Fridge freezer space is limited on a boat and is precious. I would like a fridge that requires minimal power to keep cool which equals a well insulated fridge. Unfortunately using conventional materials a well insulated fridge has a large volume of insulation with only a small space for perishables. This aerogel could make a big difference to both the overall performance of a fridge as well as improved capacity. It would not be difficult to knock up a fridge freezer compartment with ply, glass fibre, epoxy etc.

I have been trying to do the calculations for lining the hull but I am afraid that I am using too many rules of thumb to get an accurate answer. It would be a costly product to use but it would be a significant space saver.
 
pmagowan said:
Well a fridge was one of the uses I was thinking of. Fridge freezer space is limited on a boat and is precious. I would like a fridge that requires minimal power to keep cool which equals a well insulated fridge. Unfortunately using conventional materials a well insulated fridge has a large volume of insulation with only a small space for perishables. This aerogel could make a big difference to both the overall performance of a fridge as well as improved capacity. It would not be difficult to knock up a fridge freezer compartment with ply, glass fibre, epoxy etc.

I have been trying to do the calculations for lining the hull but I am afraid that I am using too many rules of thumb to get an accurate answer. It would be a costly product to use but it would be a significant space saver.
Click to expand...

Yes, I saw that - but I was emphasising the case where someone wished to increase existing coolbox insulation without ripping the box out, where access to all external sides is difficult and where there may be a reluctance to use expanding foam. Internal panels with food grade surfaces are available, but are fairly thick for the insulation they achieve, so considerable internal space may be lost. It occurred to me that Aerogel might offer advantages in that particular case.
 
Hydrozoan said:
Yes, I saw that - but I was emphasising the case where someone wished to increase existing coolbox insulation without ripping the box out, where access to all external sides is difficult and where there may be a reluctance to use expanding foam. Internal panels with food grade surfaces are available, but are fairly thick for the insulation they achieve, so considerable internal space may be lost. It occurred to me that Aerogel might offer advantages in that particular case.
Click to expand...

Yes, that is a similar situation but in retrofit. Essentially the problem is that for ever inch of insulation you put in you lose an inch of storage space for the perishables. If you count all sides that is 4 inches. So, the more efficient the insulator is the less space you would lose. I am sure you could easily make up an insert for an existing fridge that would allow a sheet of aerogel to be fitted.
 
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