Happy Winter Solstice!
It’s that time of year when the days are short as the sun travels its lowest and shallowest path across our sky. Passive solar homes are ones that integrate with their environments and take this into account.
If a passive solar house has its windows facing the south, on the Winter Solstice, the sun’s warmth reaches deep into your house to warm it when it’s most needed.
The tile floor (having thermal mass) absorbs the heat and slowly releases it to warm the sun in the evening and through the night. Learn more about this home located in the North East.
Here are some images of passive solar homes in the winter from past articles.
The last two images are from an off-grid passive solar Earthship-style home. Earthships use old car tires as a building block. The curved back wall covered with adobe is a massive tire wall that holds the sun’s heat in the winter, while in the summer (because the sun does not shine on it – as it travels a high, wide arc) it helps to keep the home cool.
This is from a grid-tied passive solar log home that frequently reaches net-zero in the summer.
This is from a comfortable, off-grid, super efficient passive and active solar home.
Why does this work out this way? Because the sun’s movements are predictable. Building homes to this predicable pattern, using certain materials along with the building’s orientation, allow passive solar homes to be cool in the summer and warm in the winter while using less external heating and cooling costs.
Here’s more on the movement of the sun. (As a side note – the Earth actually moves around the sun. We say that the sun moves around the Earth because from our day-to-day point of view, it appears that the sun rises in the east and and sets in the west, moving across the sky.)
This diagram shows the interaction between buildings and the sun on the winter and summer solstices. Passive solar homes integrate a few basic principles for building: they have thermal mass, windows on the south side, have good insulation and some type of overhand or solar control to block the sun in the summer.
Happy Winter Solstice! After today we’re looking forward to longer days. 🙂