Chelsea Green Publishing

Chelsea Green Blog

Celebrate the Winter Solstice by Using Windows to Heat Your Home

By James Kachadorian, author of The Passive Solar House, Revised and Expanded Edition: The Complete Guide to Heating and Cooling Your Home

Most people think that solar heating involves some sort of complicated roof top add on feature to a home. In a passive solar home, windows are the primary means of collecting free solar energy. South faced windows are extremely efficient solar collectors. Clear dual glazed (double pane) windows allow up to 91% of the incident sunlight to pass through them. Once the sunlight is in the home and strikes an object, the sunlight turns to heat. The heat is then trapped in the house. This is referred to as the “greenhouse” effect. The greenhouse effect, as it relates to our planet, is written about extensively as a negative effect but the greenhouse effect is quite beneficial to a passive solar home. A passive solar home works without any mechanical assist; that is, a passive solar home collects solar heat and stores the heat for use when the sun goes down. The low angle of the winter sun “turns” vertical south faced windows “on” as solar collectors and the high angle of the sun in summer “turns off” south faced vertical glass in summer. Today is the winter solstice which means that the sun is at its lowest angle in the sky. At north latitude 40 degrees, a south faced window collects more than twice the amount of solar heat in December than it does in June. As can be seen in the solar home pictured, the low winter sun will penetrate the home 22’ at solar noon on December 21 and conversely will only penetrate inches in the same home at solar noon, June 21.

All the home owner has to is face the home true south and properly size the amount of south faced glass. Too much south faced glass will actually overheat a solar home in winter. Too little glass will make the home dark and cave like. The idea is to have just the right amount of glass for the size and location of the home.

We can expect a passive solar home to be about 50% efficient in northern New England and the 60 – 70% efficient in Virginia. This means that up to half the heat needs to come from another source. Recently wood pellet stoves have become a popular way to provide the balance of the heat needed in winter. Wood pellet stoves are an attractive option for several reasons:

  •   Wood pellets are made from wood products that normally go to waste.
  •   Wood pellets burn very clean and are a renewable source of energy.

The stove pictured has a rear hopper into which the pellets are loaded. The stove has two small electric blowers – One to circulate the heat and one to feed the pellets into the burn chamber.

Another nice advantage of the wood pellet stove is that it runs automatically. Slight disadvantages are that you can hear the small electric motors running and the stove does need electricity to run. A stove such as the one pictured will use about 100 watts an hour to run amounting to pennies a day in electrical cost. For those of you that are using my book, The Passive Solar House, to calculate the amount of wood pellets needed per season, select the wood back-up heat option on the included CD. Determine the number of cords of wood needed and multiply it by 2/3 to obtain the number of tons of wood pellets needed per season.


Prepare! Keep a Grab-n-Go Survival Kit Handy

Are you prepared in the event of a sudden emergency? Blizzard, earthquake, insurrection after the inauguration? We know a lot of people are wondering what’s coming next in the US, as well as the world, given terrorism, politics, and global warming, among other threats. In this excerpt from When Technology Fails, a popular book on […] Read More

A Bloggin’ We Shall Go: Your Favorite Blog Posts from 2016

Ah, 2016 – where did the time fly? It seems like only earlier this year we were excited about designing swales and getting to know more about no-till farming, and we ended up focusing on the heart, ketogenic diets and seeking a bio-abundant future. While the top 7 blog posts of the year don’t exactly […] Read More

Yes, America We Can Make It … Really

Uncertainty got you down? The political world may seem like it’s crumbling around us, but this we know: We can make it, America. Literally, we can make things. Houses. Gardens. Food. Below we’ve selected some of our classic how-to and DIY books (and some new favorites) to help you sustain your self, family, and community. […] Read More

Chelsea Green on Instagram: Our Most Popular Photos of 2016

What a year for Chelsea Green on Instagram! We began the year with 500 followers and are now fast approaching 4,000 photo-loving brewers, gardeners, cheesemakers, permaculturists, foodies, seed-savers, homesteaders, foragers, and more. Our most popular posts of 2016 say a lot about what makes you happy: mushrooms, innovative garden designs and techniques, tiny cabins, and […] Read More

Get Ready, Get Resilient

Are you resilient? How about we put your answer to the test, literally. Now, we know that assessment is always an important, albeit imperfect, subjective, and incomplete tool. In order to understand one’s skill in living a resilient lifestyle, Ben Falk, author of the award-winning The Resilient Farm and Homestead, developed the following assessment tool. […] Read More
Follow us
Get every new post delivered to your inbox
Join millions of other followers
Powered By WPFruits.com