Making a Winter Job Easier

Making a Winter Job Easier

improving snow removal from our hoop structures

     Well, the winter snows have arrived and that means removing snow from the roof of our hoop greenhouse structures so that the weight doesn't damage the metal bows; a task that is both laborious and time consuming. Last year and up until today we used brooms on the inside to push the snow off without harming the 6 mil plastic cover. Then we'd grab shovels and move the snow away from the walls so that the next snowfall would have somewhere to go. It was quite an arm work out, and only mildly effective in that we weren't getting the snow off the very top.

     And so we've been experimenting with various ways to make the job easier. Carina made a device yesterday that's showing itself to be pretty effective. It is a cross between a broom and a squeegee; with a long handle for reaching, and a flat piece of wood paneling wrapped in duct tape for scraping without puncturing the greenhouse plastic.

Carina pulling snow down from Vermadise's roof

     Another option is utilizing a small wood-gas stove to try to melt the snow off of the plastic roofs from the inside. The results of this strategy would be even better than scraping because snow would not build up on the sides of the buildings as the winter progresses.

     We've long used a small solar-powered wood gas camp stove as a teaching aid , and this fall we acquired it's big brother with hopes of using it to heat up Vermadise during heavy snowfalls figuring that it would be more pleasant to sit inside feeding a fire than to be outside shovleling snow.

     A few weeks ago when the first notable snow fell, Patrick and Carina experimented with the new camp stove to see if it was capable of clearing the snow off the greenhouse. Unfortunately they weren't able to get a proper burn going, and were smoked out.

     Since then Walt, Opalyn and I have since done a few experimental burns with the TLUD (top lit updraft) woodgas stove on cold days (temps in the low 20's°F) to see how temperature affects it. Our determination is that the wood chips we were using were too wet to burn effectively.

     Damp wood will not reach temperatures substantially over 200 degrees Fahrenheit until the water it holds has evaporated. That is why the stove was smoking--the damp wood wasn't getting hot enough to burn completely. And without it going through the pyrolytic phase (500°F to 800°F) there is no charcoal formation, and without a bed of glowing charcoal (1800°F to 2200°F) the pyrolytic tars (smoke) won't be completely broken down into burnable gases.

     What all of that means is that until the damp wood chips become dry enough and hot enough, there will be a smoky fire. What we were looking for was a cleaner processing of that smoke into wood-gas leaving little or no tarry residue in the air.

      I want to emphasize that there's nothing wrong with the wood gas stove we were using; it just needed properly prepared fuel. While our summers are dry, our winters are humid, and wood chips that are left open to the moist winter air will take on moisture. Next summer we'll put up a sealed drum of wood chips that will then be reserved for this application.

     But for now, our solution to the problem of moisture is simple. Begin drying small amounts of wood chips on the traditional wood stoves in the kitchen. Then we will have a supply available when we need to clear snow. Hopefully moisture truly is the problem, and we have another tool in our repertoire for maintaining our greenhouse structures in the winter.

     As the snow continues to build up on the greenhouses, it is apparent to me how important it is to understand how to use the technology before we actually need to use it--a rule which applies to just about everything we're doing here. I will post updates as I discover more about the fascinating world of Gasification.

Notes From Windward - Index - Vol. 70