Bob Stuart

The chips are out of a common garden appliance.  A few sticks under 1/8" made it through, but the main output is irregular chunks that would pass through a 1/2" hole.  I could scrounge up another, matching tent heater, but I don't want to make a huge project out of this if it is only a tiny percentage of my carbon output.  

I have about four bushels of wood chips, ranging from green to rotten.  I have a tent-heater airtight available, and some open-burn opportunities in the fall.  Is this enough material to bother with, and how would you convert it if it is?

I use several different well-tested bags, including one very strong canvas affair, but my favourite is a 45 year old nylon mesh bag that was standard equipment for housewives in Rome who wanted something strong yet small when not in use.  I use it for the vegetables that then go into the 12 volt cooler for the 2 to 4 hour drive home.  When pressed, I can use the cooler, and two more layers of passive coolers, a 6-pack container inside a 12-pack container, with ice, and get even frozen food home in the summer.  

I got an electric food warming tray at a garage sale for a footrest.  I added a dimmer switch to get the temperature down, a light to remind me it is on, and tapered supports at each short side to give it a bit of angle and make it easy to slide around with my feet.  

I've been prototyping radically efficient, benign technology for most of my 75 years.  I'm very frustrated by not having a single student.  

For art's sake, I improve or re-manufacture brassware.  I only buy it for less than scrap value.  

Thanks, David.  I have been using roughly-carved styrofoam blocks set in a "mortar" of spray foam, trying to avoid all air gaps behind and between, but I know the job can't be perfect.  I've tried to arrange for drainage, but again, it can't be perfect.  If I were doing it again, I'd use all spray foam.  Considering all the fuss I've had, doing a perfect vapor barrier with fiberglass might have been easier.  

Thanks for the terminology, Terrell.  What I'm finding is too big, too expensive, and unsuitable.  I don't want any humidity recovery, and maximum heat recovery.  For now, I'm  doing some insulation because it has to go in first, but I'll just finish the unit for occasional, above-freezing use for now.  If I do need it for continued and/or colder use, I'll add a wood stove first, and see if I need enough ventilation to make the heat recovery job worth it.  One nice thing about wood heat is that I can extract charcoal for biochar to be a good citizen, not just a fuel waster.  If I expect to be driving 20% of the time, I'll go to the wax tank to store engine heat instead.  

Robert Ray wrote:With such a tiny house storing 20 gallons of heated wax is a pretty big volumetric bite out of available space. My problem with propane heat is the volume of condensate that comes with their use. I'm with Johnathan on the small wood stove, that could be used as your cooking appliance as well. Venting the humid inside air to the outside will probably be key to whatever design you are looking into. Just exchanging heat while retaining interior moisture from sweating, breathing and propane usage might not address the condensation issue. Ventilation sounds like an important piece of the puzzle.

The whole point of the heat exchanger is to have high rates of ventilation without wasting much heat.  Moist air goes out and dry air comes in, but pre-warmed for free.  Agreed that a wax tank would need significant volume, but so does a wood burner plus fuel.  

That's an interesting point about the possibility of the heat exchanger itself icing up, and one I'd have to keep in mind.  However, I should have probably stated that the purpose of the heat exchanger is to just expel considerable quantities of moist indoor air while recovering the heat for a corresponding intake of fresh, dry air.