Campus Tours:Old Main Overview
From HUG Wiki
Contents |
Old Main - Overview
Plan
Old Main, our first Campus building, is intended to heat itself year-round. We are approximately 80% of the way to where we want to be. Originally, we planned to just build a steel shop building to use as a launching point to build small experimental cabins of straw and cob. When it came right down to it, we just couldn't force ourselves to build another wasteful building, so we made our shop of straw bales. It worked out well because it is big enough to try many different techniques in the same building.
Straw Bale Walls
The walls are stacked 3’x3’x8’ straw bales that provide excellent insulation against the cold in the winter and the heat of the summer.
The insulation R-Value is around 100 (compare this to homes built with 2x6 stud walls that have R-Values in the lower twenties).
Catching some rays
The building design and deliberate orientation allow Old Main to take advantage of passive solar heat. To get an idea of the strength of the passive solar heat on a very cold (-20°F) but sunny day we are comfortable in t-shirts upstairs with temps up to 80°+.
The angle and amount of overhang on the roof is intentional. This allows in maximum sunlight during winter when the sun is lower in the sky. During the hot summer, when the sun is higher, the overhang limits the amount of passive solar heat that enters the building and helps keep it cool.
Keeping the heat
The hottest air in the building rises to the ceiling and is pulled into the ducts that line each of the windows on the south wall. The heated air is then pulled by fans into tunnels located two feet under the floor, heating about a million pounds of earth and floor. This acts as heat storage, cooling the hot afternoon air and keeping the building warm all night.
