The best way that I can think of to add a large amount (20+ tonnes) of thermal mass to a solar home is by adding concrete floors. By doing this, one can get two uses, thermal storage and a finished floor,  out of the same investment. Furthermore, since the mass of a concrete floor is so spread out around the home, thereby giving it a large surface area with which to absorb and release heat, it really is the ideal thermal storage medium for a house with large solar gains. Read the rest of this entry »

(Pouring concrete, main floor, MCNZH)

A lot has been achieved in the three months since my last progress report.

Concrete Floors and Counter Tops

We poured concrete floors over the subfloors a couple of months ago. We originally framed the walls of the house 2.5 inches higher than normal to accommodate the depth of the floors. We also had to put posts and beams down the middle of the house to support the 10-12 metric tonnes of weight per floor that the concrete weighs. Finally, we poured high fly ash Agilia concrete over the subfloors: Read the rest of this entry »

(MCNZH concrete floor being bathed by sun through a 9’x6’ window)

The most important design considerations for cold climate building are insulation, building envelope, and passive solar design. Given our lofty goals for the Mill Creek NetZero Home (MCNZH), we pushed hard to maximize our return on every one of these fronts.

The MCNZH collects 54% of its annual space heat through passive solar design – that’s 8747 kWh or 31.5 Gigajoules. It does so by:

1. having huge south windows that are specially manufactured to maximize solar heat gain
2. containing a large amount of thermal mass to absorb the solar heat when the sun shines
3. having movable solar awnings that allow 100% of the sunlight to hit the windows during the heating season (the awnings are strictly speaking not a passive part of the solution). Read the rest of this entry »

A Scan Andersen 10 woodstove, installed in the MCNZH.

People commenting on a recent national CBC article about Edmonton’s NetZero Energy houses spent a lot of effort criticizing the fact that the Mill Creek NetZero Home (MCNZH) has a wood burning stove. Besides proving beyond a doubt that the only thing worse than an ignoramus is an anonymous ignoramus, the comments taught me a bit about what messages to send in a sound bite culture such as ours. Read the rest of this entry »