Paper Title
Greenhouse Growing Season Extension in Alaska Using Evacuated Tube Solar Collectors and Thermal Mass

Abstract
Many efforts have been made to mitigate the food security problems in the arctic and subarctic areas in the world. The purpose of the present research is to study ways to prolong the growing season into the boundaries of still colder months in an efficient and effective manner. A greenhouse was built to receive sufficient solar irradiance and to minimize the heat loss through the walls, roof, and floor. The greenhouse utilizes additional solar heat energy collected by the means of solar evacuated tubes. The collected heat energy is continuously retained throughout the days in a trough filled with cinder blocks. After the sun sets and the temperature drops, the retained heat is transferred to the greenhouse throughout the night. This maintains the ideal temperature for crops so they do not freeze. The mathematical model and measured temperature data show that the greenhouse we propose allows extending the growing season in Alaska by more than a month. Keywords: Greenhouse, Evacuated Tube Solar Collectors, Thermal Mass, Temperature Fluctuation, Solar Thermal.