Did you see the Mountain Xpress article about M R Gardens' passive solar greenhouse? Here it is....
June 6, 2016, By Virginia Daffron
The paradox of commercial greenhouses has always bothered edible landscaper Megan Riley.
While the greenhouses allow professional growers to get a jump on
starting seeds for food crops and landscape plantings, they require
significant energy resources to operate. That means the houses aren’t
necessarily sustainable, Riley says.
Riley’s longtime dream of creating a commercial-scale passive solar
greenhouse for her business, M R Gardens, became a reality in
January when she completed an 800-square-foot facility in Oakley.
Though conservation-minded gardeners have experimented with similar
structures on a small scale for at least the last 50 years, Riley says
commercial producers in the nursery trade haven’t embraced the
The greenhouse features large windows facing south, not just for
plant growth, but also for optimal solar gain. During the day, the sun’s
rays fall on large plastic drums filled with water. The drums store the
heat and then release it slowly overnight, moderating temperatures
inside the structure. “It’s like living next to a body of water, where
the temperature fluctuations are less extreme,” Riley explains.
To keep all that heat in the building, Riley specified a high R-value
for the north wall insulation. The acrylic double-walled window panels
she selected also hold in more heat than single-paned glazing or plastic
film. Since starting her first seeds in January, Riley hasn’t needed
any supplemental heat to keep the greenhouse within the ideal growing
range of 55-85 degrees, even on the coldest nights.
Read more here.