--- In FairfieldLife@yahoogroups.com, grate.swan <no_re...@...> wrote: > > http://streaming.mou.org/MOU/Chat/19_Jan_09.wmv > > Interesting video on M. Vaastu use of sandbags for construction. > Anyone who has made sandbag barriers in times of flooding may "get > it" immediately. No foundation, on-site material (in many cases), > extreme sound and heat insulation, flexible to earth adjustments, > cheap, ecological, quick, can be constructed with limited > construction skills, etc. > > > Any experience with such? Thoughts?
The exterior walls of our original house are made of rammed earth blocks (two 8" rammed earth walls with a 4" insulated gap in the middle), and a very important lesson learned is that thermal mass is NOT the same as thermal insulation. Thermal mass is great in locations where there is a large temperature difference between day and night, because the thermal flywheel effect keeps the inside of the house at an even comfortable temperature. In Fairfield, there's a certain amount of that in spring and fall. However, during the extreme seasons where there is only warm and warmer or cold and colder, the performance of thermal mass totally sucks. In adding on to our house, one of the goals was to wrap as much well insulated new house as possible around the original earth block walls. That's not to say that thermal mass is completely useless in Iowa's climate. Thermal mass is great for maintaining even temperatures inside, however, in climates like this, you *must* fully insulate the wall system on the outside. Even with the thermal break in the center of our earth block walls, the inside surfaces of those walls in winter were freezing cold to the touch. Bottom line: beware the hype and romanticization of thermal mass!
