Progress on our heat duct tunnel continues:
While formwork for the wall extension was removed, formwork construction for the roof slab began. Since the slab will also be the new entrance for the pool area, it was designed with extra structural support beams.
Here the formwork nears completion. The construction crew measures and prepares for rebar connections into the existing slab.
A view from underneath the roof slab shows preliminary wooden shoring and the steel support beams.
This hired backhoe helped to smooth the way for the future extension of the heat duct tunnel. Design of the steepest tunnel section (from the pool to the greenhouse) is underway.
Once connected to the greenhouse, the tunnel will provide supplemental winter heating to residential spaces through the chimney effect. Hot air produced inside the greenhouse will rise through the tunnel and radiate heat into thermal mass (concrete) to help cut down our energy use.