Passive Solar Design


(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).

I’ll discuss the first two bullets on this list, given that I’ve already described the movable awnings at length.  read more... »

Happy Earth Day, Canada

How often do you pause to practice gratitude for the planet? Thanks to Earth Day, it'll be at least once a year.

And what 's to celebrate? Everything, of course! From the air you breathe and the water you drink to the food you eat and the clothes you wear.

Everything we need and use comes from the Earth. Think about your favorite things like wine, chocolate, fresh sheets, sunny afternoons, and give thanks to the plants, animals, elements, and ecosystems that make it all possible.  read more... »

Alberta Joins the Ranks of Eco-Rebate-Friendly Provinces

BC may well be the best province to live in when it comes to available federal and provincial support for greening your home.

Sales tax exemptions on Energy Star windows, insulation and more, plus Livesmart BC - a rebate program that matches federal Ecoenergy rebates for BC residents, all make living greener more affordable out West.  read more... »

How Much Energy Does It Take To Supply Hot Water?

I read an interesting article recently about how to calculate the size of an on-demand hot water heater.  OK, while not exactly what most people would consider light reading, what I thought was interesting was how much energy it takes to generate something we take for granted.  The article discussed how running a single shower would require the incoming water to absorb energy at a rate of about 75,000 BTUs per hour and that if the tankless water heater was 80% efficient, then the heater would need to have a rated input of 94,000 BTUs per hour.  If you want the ability to run two showers simultaneously, then the numbers double so that the tankless water heater would have a rating of 188,000 BTU.  (For reference, the boiler I have for heating my house and domestic hot water can modulate  read more... »