21) Walls & the Earth Tube- September '17

September saw the raising of walls and panelling. The lift was used to position the north wall.

Though it's August, you can see how cool it is in the earth tube. This thermometer is measuring the temperature about 4 feet down in the tube located in the utility room. The plan is to pipe this air upstairs into the upper two levels to provide cool air in the summer months.

Actually there are two outlets to the earth tube. The one below is located in the hot tub room. It's capped off in summer, since air won't be needed here as there will be wide windows on the three sides. In the winter it'll be opened, and the inside tube closed off, as the last thing we'd want to do then is duct in chilled air into the main building. It would defeat the whole idea of having an airtight home! In winter, the 50 degree temperature of the air in the earth tube makes it actually warmer than the outside air. Perfect to bring into the hot tub room. Another benefit is that it will be dry, really dry. During the Vermont winter the outside humidity can be as low as 25%, bringing this air into the hot tub room to replace the humid air will ensure the room is dry and comfortable.

This photo shows the earth tube intake located about 100 feet from the SunCottage. The green tube is for winter use, aimed at keeping the intake above the snow. In the summer, after the spring thaw and high water, we'll remove the winter tube and add an extension to get the intake closer to the chill air near the stream. On September 15th I measured the temperature of the stream water, it was a cool 59°!