Sheep Wool Batts for Insulation?

[LoveandRage]

Originally Posted by Doodlebee

Thanks for saying that about wool (avid knitter here, myself...wool is AMAZING).

I was thinking of going the wool route too (for sustainability), but after investigating a bit, the downside is the R-value. if you've only got 1.5" to put the wool in, the value is something like R-7. I feel like that wouldn't work very well in colder environments. I live in CT, and we just replaced out house's insulation 5 years ago, and what was in the walls was R-9, and it was always chilly in the house. (we went spray foam almost everywhere, and it's been an amazing change, both for our heating bills and the silence from outdoor noise).

Just curious if it's different on a bus, than in a house? Did you go to colder climates and see how it worked there?

We’ve camped comfortably in sub-20 degree weather. We didn’t delete any of the glass in our bus. That’s a MUCH bigger source of energy loss than any kind of insulation can make up for, hence why we use reflectix in the windows during extreme heat and cold. We also have a king size wool duvet to cuddle under at night and propane heat during the day. Tank heater on the grey tank and fresh tank inside. All of this specifically for winter camping. I don’t think we’ve ever gotten under 50 degrees inside the bus even during extreme cold.

We used spray foam (foam-it-green) in our last house. The concern I have with spray foam is that it will trap moisture IN as effectively as it will keep it out. If moisture gets between your foam surface and your interior walls, you’ve introduced a perfect condition for mold and rot. With the levels of moisture we’ve dealt with in the southeast and the PNW, it’s very important to us to have an insulating material that breathes. I am extremely sensitive to mold. Wool is the perfect insulator for cases where moisture may be present. Spray foam is better in situations like a temperature controlled home interior where there aren’t any concerns about moisture intrusion in the walls.

[john61ct]

I put "organic" in quotes intentionally.

Some people are (or claim to be) very sensitive to chemicals from off-gassing, concerned about toxicity indoor pollution etc

and that motivation is what drives them away from spray foam, XPS/polyiso etc.

Thus my pointing out wool is not really free from those concerns if treated against critters making themselves at home.

The other green concern of "sustainability" is of course a completely different argument.

[LoveandRage]

Originally Posted by john61ct

I put "organic" in quotes intentionally.

Some people are (or claim to be) very sensitive to chemicals from off-gassing, concerned about toxicity indoor pollution etc

and that motivation is what drives them away from spray foam, XPS/polyiso etc.

Thus my pointing out wool is not really free from those concerns if treated against critters making themselves at home.

The other green concern of "sustainability" is of course a completely different argument.

I guess I share all of these concerns to an extent but there’s a lot of nuance to consider and the devil is in the details, as usual.

As far as I know, boric acid actually would qualify as an organic pesticide. Borax certainly is embraced by the organic food and farming community as a safer pesticide. And safer is generally what we’re going for. But I’m sure there are purists who would disagree and who would consider even safer pesticides such as neem oil to be off limits. I don’t generally argue with those types. To each their own. I am personally satisfied with the safety of boric acid in this use case. I wouldn’t want my duvet treated with it but I’m not concerned with it being in the walls.

As for spray foam, it depends on the type used as to whether it off gases. I limit my exposure to open cell foam. Closed cell foam shouldn’t be an issue. They will all break down to some extent over time and produce dust that isn’t particularly healthy for people to breathe. I choose to think that with all of the windows and breeze inherent in a bus, this space is probably pretty safe in terms of indoor air pollution. In fact, it’s outdoor air pollution that is my greatest concern when traveling. Living in a vehicle like this is basically living outside. We were on Mt Hood in Oregon when the fires broke out last year. We couldn’t breathe in the bus even with the windows closed. I’m sure again that there are folks who are very concerned with indoor pollution in their rig but it isn’t a concern I share in this case.

[Happy.Pappy.Bus]

Originally Posted by Doodlebee

Thanks for saying that about wool (avid knitter here, myself...wool is AMAZING).

I was thinking of going the wool route too (for sustainability), but after investigating a bit, the downside is the R-value. if you've only got 1.5" to put the wool in, the value is something like R-7. I feel like that wouldn't work very well in colder environments. I live in CT, and we just replaced out house's insulation 5 years ago, and what was in the walls was R-9, and it was always chilly in the house. (we went spray foam almost everywhere, and it's been an amazing change, both for our heating bills and the silence from outdoor noise).

Just curious if it's different on a bus, than in a house? Did you go to colder climates and see how it worked there?

I see havelock makes the r7 for #vanlifers but I had the same thoughts in the R value. Anyone who has used the r7 or managed space for the r 13 I would love to hear your feedback on it.

[Simplicity]

I think each insulation products have their pros and cons, and depending on your situation, one will lean this way or that way.

No matter which product you use, the key to not having mold is not having excess moisture.

Focusing on how to keep your humidity low and air flow high will do more the most avoiding moisture related issues.

I happen to use rigid EPS, but was not happy with how poorly it fit. Lots of air gaps and such. To address this, I have decided to use a non-organic wool type product to stuff between gaps to help keep any moisture in the air from getting to the metal.

I'm also planning on using Tyvek type product between the insulation and the ceiling covering. It resists allowing moisture in, but lets it escape.

After learning more about controlling condensation, I'm going to review how to exhaust my cooking and shower moisture, along with increasing the air flow.

I know wood stoves rock at keeping humidity low, but I'm not convinced I want to use one. I may keep a dehumidifier on-board, and if needed, run my generator to keep moisture levels down.

For me, reducing moisture has become more of a preventative priority, so I minimize the possibility of having to redo any of all the work I've done.

Per the organic wool, you could always run a test and see how it works.

[john61ct]

Spray foam is best for sealing gaps and preventing bridging when using rigid panels for the bulk of your R-value.

Getting as close to perfect a vapour barrier as possible is the key

not just to preventing mold, but preventing temperature leakage via air infiltration / convection

R-value against radiative transfer being pretty useless without a well-sealed envelope.

Then the mylar / whatever sheet for additional moisture prevention is icing on the cake.

Basically the goal is ZERO uncontrolled ventilation

then adding LOTS of controlled ventilation.

Core design principle:

Pretend you will be living long term off grid, FF costs yriple what they are now,

3 months in Death Valley paying for a genset running aircon

3 months in high altitude windy ski country or interior Alaskan winters heating off propane

then in the super humid PNW in both summer and winter rest of the time.