Eighty Degrees in February

Our hoop house made it up to 80 degrees this afternoon in spite of subfreezing temperatures outdoors.  The structure is approximately 8 ft. x 14 ft., with an eight foot ceiling at the back.  It covers two large potting tables and a 100 gallon Rubbermaid feed tank full of water.  The water tank is a convenient source for irrigating plants, and serves as thermal mass to help regulate the temperature of the hoop house.  The back wall, painted white, is the south wall of our adjacent garden shed.