Thermal Insulation

[davidkaleta]

Hi all

I've tried to search in the forums for an answer, but so far nothing. My question is this, so assuming that not all of us sail in perfect warm weather conditions, why do so many manufacturers not insulate their hulls with additional insulation. I plan to spend some time in the UK waters and possibly Norway and such. But condensation, additional heating etc would make this uncomfortable.
I see no reason that bilges, hulls and above cannot be addressed.
I read somewhere that a new client of a leopard 50 asked for exactly this, and was told no problem, additional cost!

[marshmat]

Additional cost is exactly why insulation is often omitted. For a substantial fraction of use cases, it's not needed. So why spend the money and the labour, adding weight and taking up space?


Insulation materials that work well in a boat, and are sufficiently fire-resistant, and don't readily grow mildew, are *expensive*. They'll only be installed if enough buyers ask for them and are willing to pay the premium.

[Statistical]

Originally Posted by davidkaleta

Hi all

I've tried to search in the forums for an answer, but so far nothing. My question is this, so assuming that not all of us sail in perfect warm weather conditions, why do so many manufacturers not insulate their hulls with additional insulation. I plan to spend some time in the UK waters and possibly Norway and such. But condensation, additional heating etc would make this uncomfortable.
I see no reason that bilges, hulls and above cannot be addressed.
I read somewhere that a new client of a leopard 50 asked for exactly this, and was told no problem, additional cost!

You answered your own question. Additional cost worse it is additional cost that doesn't look pretty at the boatshow. If you have to ask why do they do "x" it is almost certainly because of cost. Why are many boats built as a liner in a hull which makes future upgrades and maintenance harder over the entire life of the boat ... it is cheaper. Nobody goes to a boatshow going "I wonder what type of inuslation did they use" or "how accessible will it be to replace this tubing in 15 years".


Even in homes if there weren't regulations new homes would have a lot less insulation. By the time the buyer realizes this poorly insulated house cost a fortune to heat/cool well that is his problem not the builders.

[davidkaleta]

Ok, I get the cost factor, however, I rarely see a manufacturer putting it in the options list. But let's be honest, closed cell foam with an R value of 7 or so, is not going to break the bank, especially at a time when it's simple and fast to install. I think this would be a additional selling point.
By the way, thanks for the replies.

[LakeSuperior]

If insulation was easy and fast to install you could do it yourself.

Consider, the manufacturer has to spec it, source it, size it for each section of the interior hull, fasten it with an adhesive that won't fail over time in a moist environment, and then complete construction without damaging it with install of the remaining interior of the yacht.

[thinwater]

I've cruised my cat in sub-freezing conditions many years:

• The best insulation is cored hulls (above the WL) and superstructure, the thicker the better. The hull liner also adds some. This is good for heat and AC.
• Your biggest heat leaks are going to be windows and doors. Make sure you can fit double windows in the winter.
• Carpet on the floor.
• Good fuel-driven heating system will keep the humidity low.
• Covers and draft stops.

Since most cats are cored and most have liners, it's not about insulation, it is about the details.

[Tupaia]

Cook with kerosene, diesel or electric. Gas cooking results in a damp miserable environment and a haven for mould.


Use external insulated covers on hatches over berths or soft furnishings. It is important to insulate the frames, internal insulation will not achieve this.

[noelex 77]

Insulation makes a huge difference to comfort. Condensation in particular can make boat life very uncomfortable. When equipping a boat, many focus on extras, but the basics of keeping the boat dry and at a comfortable temperature are far more important.

A cored deck (virtually universal) and hull is a slight help, but the insulation effect is minor. Unfortunately, good insulation requires several inches of space. It is generally difficult for production boatbuilders to to able to find this room, so additional insulation (if offered) is often a token effort. However, if planning to cruise Norway any extra insulation, even if thin, is worth adding.

[Cheechako]

Well, ....you could buy a cored hull boat. Decks are cored so they are insulated. I insulated much of a 31 footer I built, It was a PITA and living aboard in the PNW didn't seem much different than the non insulated boats I had. I only used 1/2" foam insulation above the waterline and at best got 75% of that in the living area.

[250224]

Originally Posted by Cheechako

Well, ....you could buy a cored hull boat. Decks are cored so they are insulated. I insulated much of a 31 footer I built, It was a PITA and living aboard in the PNW didn't seem much different than the non insulated boats I had. I only used 1/2" foam insulation above the waterline and at best got 75% of that in the living area.

I would suppose that the insulation effect was a bit diluted. From reading/asking around I think a more involved approach is required:

- at least 3/4" but better 1+ inch thick
- armaflex instead of foam insulation
- also insulate below waterline (water has a much higher conductivity than air)
- 3M window insulator kit
- companionway? Difficult if one doesn't have a proper door (once tried with bubble wrap, somewhat helpful but not optimal either)

[PirateGuy]

By the same token, some IR reflective film (little space lost) under decks and along topsides might help reduce solar heat gain in tropical regions.

[Montanan]

Originally Posted by blu3534

I would suppose that the insulation effect was a bit diluted. From reading/asking around I think a more involved approach is required:

- at least 3/4" but better 1+ inch thick
- armaflex instead of foam insulation
- also insulate below waterline (water has a much higher conductivity than air)
- 3M window insulator kit
- companionway? Difficult if one doesn't have a proper door (once tried with bubble wrap, somewhat helpful but not optimal either)

FYI:

Armaflex is a closed cell elastomeric foam insulation. There be many closed cell foam manufacturers. Of issue with these is that condensation forms on the side adjacent to the hull as it is not sealed or in contact with the hull surface.

Recommend that one use spray-on urethane foam, like they do on steel boats, where condensation can lead to disaster, not just discomfort. This type of insulation bonds to the hull and deck surfaces, perfecting the separation required to prevent condensation.

[GordMay]

Originally Posted by PirateGuy

By the same token, some IR reflective film (little space lost) under decks and along topsides might help reduce solar heat gain in tropical regions.

Radiant barriers [IR reflector] should be installed with a minimum ± 1.0 inch (2.5 cm) air space, between it and the exterior envelope [hull/deck].
Radiant barriers work best at 90 degree incidence, so most useful for deck [little use on hull].
They do virtually nothing, for heat LOSS.

[250224]

Originally Posted by Montanan

Armaflex is a closed cell elastomeric foam insulation. There be many closed cell foam manufacturers. Of issue with these is that condensation forms on the side adjacent to the hull as it is not sealed or in contact with the hull surface.

the material must be tightly bonded to the hull. There might be other foam manufactures but Armaflex seems to be the best.

Recommend that one use spray-on urethane foam, like they do on steel boats, where condensation can lead to disaster, not just discomfort. This type of insulation bonds to the hull and deck surfaces, perfecting the separation required to prevent condensation.

Here (https://setsail.com/armaflex-insulation/) is what Steve Dashew wrote: ..."

2-Sprayed foam absorbs water from the air and over time loses its insulating capabilities, in addition to which it is a great mold factory. Also, the foam continues to release unpleasant gases throughout the early years (or more) of its life.

3-We chose Armaflex because it has the lowest moisture absorption rate we could find. It is also very good on noise attenuation." ...

[Edit] and here (SetSail FPB » Blog Archive » Adding Insulation to Wind Horse) another description. Pay attention to the comment where one person "removed 100+ garbage bags of old, mouldy, mildewy, water soaked foam" and is "not convinced"

[davidkaleta]

Thanks for all the posts guys, appreciate it.