MacKinnon Greenhouse
The passive solar greenhouse in the Colton Garden was one of the first of its kind. The greenhouse was designed and built by David MacKinnon in 1976. MacKinnon was a physicist and meteorologist residing in Flagstaff while working for the US Geological Survey. He had a special interest in the development of passive solar greenhouses and received funding from the Rodale Institute to construct two of his greenhouse designs, one on the grounds of the Rodale Institute in Pennsylvania and the other at the Museum of Northern Arizona.
MacKinnon took careful notes on how his greenhouses gathered and retained heat and later wrote a chapter on heat storage for The Solar Greenhouse Book published by Rodale Press in 1978. From his experiments in Flagstaff, he ended up recommending a method of heat storage that used multiple water containers stacked to maximize the thermal contact. He wrote:
My Flagstaff greenhouse maintained an average January low temperature of 49.8 degrees Farenheit, while the average low outside was 12.4 degrees Farenheit.
A copy of the Solar Greenhouse Book resides in the Colton Garden lending library located just inside the greenhouse door. Feel free to visit the greenhouse in the Colton Garden, where it is one of several season extenders in use.