A few basic parameters of the current house design. South windows are properly shaded during the summer.
- 63% of the window area faces south
- 19% of the windows area faces north
- 13% of the window area faces east
- 5% of the window area faces west
Scenario 1. The current house design as built.
- Passive solar gains account for 11,642 kBTUs/yr of free energy. This amount of renewable energy migitates roughly 1,740 lbs of carbon annually. The annual heat demand is 4.56 kBTUs/sqft per yr, which meets the 90% reduction in heating demand required for Passive House Energy Standard.
Scenario 2. So what do the numbers look like when I spin the house 180 degrees to the north?
- As one might expect, the solar gain contribution drops dramatically to 6,268 kBTUs/yr and the carbon migitation is reduced to 460 lbs annually. Based on this example, passive solar design saved nearly 4 times the carbon compared to the home that was spun 180 degrees to the north.
This example illustrates that by taking advantage of the sun through properly placed windows you can greatly reduce the energy demand and carbon footprint of your home.