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Sunday, 22 November 2020


Interesting video. I can relate because my wife and I decided to move from our detached house to a condo next year that is now under construction. We chose it primarily because it is a good size and a good location, and just right for us. The building uses a lot of high tech construction and energy efficiency techniques: Of course triple glazing, solar panels, and heat recovery ventilation, but also a geothermal well system for heating and cooling which will be controlled using the 'home made' electricity. We live in Canada, so the heating will have to be able deal with - 30C (-20F) in winter and +30C (90F) in summer. There is no hook-up to gas. You can charge your electric vehicle in the underground garage. Even much of the water usage (toilets and the like) is from water collected in situ.

The builder has completed several projects like this in our area so we know it works well. However, the builder tells us that this will be his most efficient yet: not just net zero but net positive, and the most energy efficient condo in Canada. Even though it was not our main objective, we look forward in our very low utility bills going forward.

Your statement that the insulation for your 'pool hall' roof was very good at R8, had me looking up the specs for our new place. Not comparable of course, but our roof is specified as "greater than R80".

Related info: I am involved in the construction of a large new church (seating for about 1000 in the nave) in town, where we chose, after some analysis, to use the same technology, and is also net zero or better. We will offer free charging for electric vehicles in our car park, with our surplus energy. As an Electrical Engineer I worked out the cost of this and was surprised to discover that running a mid size EV like a Tesla would be about 10% the cost of running my premium gas using Lexus GS350.

When everyone realizes that you can be much better off going "green", there is going to be a veritable stampede away from fossil fuels.

I gotta call you on the "no energy costs" and "net negative energy consumption." Not your fault, really, considering how excited the video host got looking at the various technologies required by this "passive" house. Assuming this house operates on the grid (I didn't see anything regarding energy storage capability) in Massachusetts, it is actually running mostly on natural gas. Sure, it sends an equivalent amount of energy (at some evaluation by the power company) to the grid, and the grid gets a small fraction of one percent greener. Even if it were running off the grid, there is the energy of the creation of the solar system to take into account. In effect, he paid his energy bills up front. With all its insulation, air tightness and passive elements, the house probably doesn't take much natural gas to heat, nor electricity to cool. But those solar panels (and all the other electromechanical systems) require quite a bit of energy to produce (most likely in China from non-renewable energy), transport and install. It will probably be decades before this house goes "net negative." I don't think Dan will get to see it. Unless, of course, he goes crazy using energy to fill in the big hole he dug with the solar system. But if he is using the grid for storage, he is just burning more natural gas. Its a tough game to win with technology alone, much easier with lifestyle choices.

In other words, US is 10 to 20 years behind the curve of what is now almost standard for new buildings elsewhere.

I had a cousin-by-marriage who built a passive house in Amherst, MA using Carter-era energy efficiency incentives. The place was incredible, if lower-tech than the building in the video to which you linked. It was really passive -- no solar -- but also no machines to move air around. In the summer, the whole house was aligned with local wind/breeze patterns and my cousin and her husband moved their bed to a screened in porch. In the winter, the house had a series of sliding Japanese-style panels so they could section off their living space and heat just what they needed. The house was so tight that they could heat with just several pieces of wood in a wood stove. On deeply frigid nights, the large south-facing windows got rigid quilted interior inserts, which prevented night-time heat loss. Last time I saw the place was in 1988, but it always stuck with me as a model of design.

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