Thursday, January 11, 2018

Warm in Cold Out

Insulation is a big part of my life and thought processes these days.  About a month ago, back when I *thought* it was cold, I put some half inch poly-iso foam in my back window.  I am so lucky I did that.  I had been looking into window solutions for a bit.  I found what would have likely been an even better solution but it would have been spendy.  It was a multi layer foil and batting with sort of a rubberized fabric on each side.  I would have wanted a double layer so I might have been looking at close to a hundred dollars just for that.  The foam was much cheaper, guessing the amount of a sheet I used it was about five dollars.  The polyiso foam should have an R value of 3, but it should pick up one more R because of the foil lining.  It won’t roll up and store like the material meaning I will have to find someplace in the house to store it.

I cut the foam by first making a template.  I still have a few sheets of the fish poster paper I have been using as my template paper the entire length of this project.  It was a lucky deal when I snagged a bunch of those posters out of that out of the trash.  I cut this paper template to match the curve of the back door frame of the van.  Once I had the template fitting good I measured the width of the door.  Then I drew out the template onto the foam, flipping the template over to draw out the other side.  I just had to make sure the distance from end to end on my template was the width I had determined earlier.

The side wall with the insulation in place, no plywood strips.
Just doing this one step made the van way warmer.  What I did next sealed the deal, if you will.  I took some lengths of the foil tape given to me by my friend Craigie.  This is the best foil duct repair tape I have ever worked with.  About three inches wide and thick strong foil.  With this tape I was able to seal the edges where it met the door frame.  The difference that made was immediate as well.  The night before I did this I had a breeze blowing across my face as I was laying in bed.  After the tape job I could barely discern air movement.   Much better night’s sleep.

I have had some people write to me on the blog asking questions about how I insulated other things and tips for living through a north American winter.  The floor has 1-1/2” polyiso foam.  It is placed flat on the metal cargo floor.  Then 1/2” particle board subfloor, then 3/4” walnut over that.  No air gap on any of this flooring.  In retrospect and with more research since I did this I realize now I would have been better off to use the regular pink foam insulation (I think the name is XPS).  The Polyiso is better in the summer, but in the winter it’s R value drops.  Since it doesn’t have an air gap, I don’t pick up any advantage of having the foil lining of this foam.

The side wall with the plywood strips in place to hold the
the insulation.  I used some expanding foam top and
bottom just to seal up the gap.
The side walls have 1” polyiso foam with a quarter inch air gap on both sides.  Maybe I should explain this whole air gap thing a little more.  An air gap means the insulation doesn’t physically touch the outer skin of the van, nor does it touch the plywood of the inner wall.  This air gap not only makes the insulation itself more effective it makes the foil layer twice as effective at reflecting the heat back into the van.  During the summertime this foil and air gap will do the same thing for  outer skin heat, keeping the van cooler inside.   When I was taking temperature readings with the digital thermometer the other morning the side walls were not so nearly shocking as the places where I couldn’t have this air gap.  The readings in fact were so non-shocking that I didn't bother to take a picture of them.  Naturally I have totally forgotten what they were.

The rear window, just as I am beginning
the tape job.
I was able to get this air gap by cutting quarter inch plywood slats that I screwed into the frame members.  This plywood had the double duty of holding the insulation panels in place between the frame members and also making this air gap.  It was a fair amount of work though because I was putting plywood over these slats I had to drill a countersink in the quarter inch plywood so the screw heads did not protrude.  The roof is just like the side walls.  One inch of insulation with the air gaps.

Underneath my bed I have one inch polyiso.  Here I am really hoping I am getting some good reflectance of my body heat back up to me.  I should have used some expanding foam around the edges as well but I didn’t.  Maybe once spring comes I will do this as well.

Expanding foam over a wheel well.
The passenger side wheel well I blocked in with scrap chunks of polyiso foam, then came back with expanding foam to seal it all up.  Over the curved surface of the wheel well itself I used row after row of expanding foam, then went back over a few spots I missed.  I have tried to keep my expanding foam use to a minimum because from what I read there are problems with getting condensation moisture behind it and forming rust on the body.  I had planned on doing the same thing on the drivers side wheel well but when I built the floor to ceiling shelf I didn’t leave an access opening.  I will have to do this same job of blocking and insulating from the back of the van —a job which is going to suck.  Right now though it has no insulation at all.  The upside is I store my cooler next to this area and it keeps everything nice and cold.  The downside, well, of course you know what the downside is.

I haven’t been using the side door at all since the weather turned cold.  I now come and go by the drivers door.  Ao I have covered the side rear door with 1” foam, sealed up at the back with tape.  I am going to buy another sheet of foam and put a layer of foam over the frontmost door as well.  I don’t know how well I will really be able to seal this since I do need to maybe get bigger stuff in and out from time to time and the back is sealed up.  I might see if I can get the two pieces of foam to slip past each other like some sliding closet doors.  I will let you know how it works out.

My plan for the frame members is to attach (glue maybe) 1/2” foam, then cover this with plywood.   But this will be tricky for a couple of reasons.  First off, and the reason why I have put it off this long is because I have to be positive I have all the wiring done.  But beyond that, I have no idea how I am going to build the corners. I don’t know if I will fashion something out of wood or find some other material. So that is just one big heap of decisions I haven’t figured out yet.

All in all, I have a few trouble areas to work on I realize this.  But all in all I am pretty happy with the insulation performance on regular cold winter days.  Those bitter cold days, well, I guess it does the best it can.  So do I.

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