leangreen.org recycled renovation on a low-budget ration

It's been another long hiatus from any update and for that we apologize, but we have still been very busy. Back in November we completed a major milestone in getting the heat system operational. Our radiant floor system consists of 3 different heating zones: the garage, the main floor and the upstairs. When we poured our foundation we embedded the pex tubes in carefully measured loops tied onto the rebar at a depth 3" from the surface. Once that infrastructure was in place we had to determine the specifics of the system that would provide the mechanics to make it all work. After a lot of research and some recommendations we purchased the majority of our system from Radiantec. They were very helpful in sizing the system and providing answers on all of the different components - I highly recommend.

We built and indirect system which means that the fluid that heats the floors is separate from our domestic hot water. This is a code requirement here and has the added benefit of allowing the use of fluids that have better thermal properties than water. On the downside a heat exchanger (lower left-hand side) is required to transfer heat from the tank to the fluid in the loops.

The system has been very efficient so far. We keep the thermostats around 59 degrees but with all of the sun we get through the windows that helps heat up the slab it is usually mid 60's by the evening. The heat turns on in the early morning hours but it doesn't take much to get back to the comfort zone. We also ran copper pipes from the mechanical room to the rear roof for future solar hot water panels...another project for another year...happy 2012!!!

We finally have one corner of our little world complete. Where our front door once was we now can gaze outside leaning on our formidable window sills. All of the trim wood and the sills were made from lumber we milled ourselves. It takes a decent amount of time to choose and process a slab into trim pieces and sills but we have been very happy with the results so far. The walls will get one more coat of plaster (note the color tests) but probably not until we are done with inspections...priorities!

Storing heat in a concrete slab seems like a standard energy-efficient building practice.  Our south-facing windows warm up the floors every morning. For wintertime oomph, Brian's been working the mechanical room, hooking up mega-gadgetry to pump hot water through the pex pipes in our floor (a major hurdle and another step closer to solar hot water).  But a Carolina engineer and home-builder, Michael Sykes of Enertia Homes, has tinkered with the phase-change of wood resin in order to amplify wood's ability to store and release heat. By doing so, he eliminates the need for other home heating sources, recycles post-industrial materials and makes stick-frame construction look like a silly sideshow. He started by discovering the improved energy efficiency of log homes and pushed the building envelope from there. The mini greenhouse-effect created in the homes sounds similar to "solar envelope construction" of the 1970s, but the resin idea sounds new to me.  Apparently the phase-change of resin from solid crystals to liquid allows wood to store latent energy at the very comfortable temperature of 70 degrees. Science Friday explains further. Worth investigating for our next project.

Looks like by the time we pay off the mortgage, the East Bay will have run out of water.  Who will be here in 100 years to appreciate all our efforts to limit our impact?  source: NRDC/TetraTech 2010.