Temperature control is accomplished by natural, convective ventilation.
Your SunCatcher has windows above the door to vent excess heat and humidity. The knee wall (short wall below the glazing) has air intake windows. This venting system works like a thermal chimney.
Cool air enters the lower vents and is warmed in the SunCatcher. The warmed air flows out through the upper vents.
During the coldest months, when the SunCatcher’s interior warms above the desired temperature on sunny days, both the windows above the doors and in the lower south-facing knee wall are opened. This allows the hot humid air to escape through these top vents and creates a natural draw that pulls dry CO2 rich air in from the outside through the knee wall windows. This outside air mixes with the warm air inside as it enters the SunCatcher rejuvenating the CO2 level while stimulating plant growth. The more you open the windows above the doors, the faster the air will enter in through the knee wall windows. It only takes a small opening of these windows on cold, sunny days to create the perfect growing environment that expels the excess heat and humidity, brings in ambient CO2 levels, and creates convective currents that aid in pollination.
The operation of the SunCatcher is correlated to the outside temperature and to the amount of available sunlight each day, which makes this system work in sync with nature. If it is a clear, sunny day, the SunCatcher will maximize solar heating and the interior temperature reaches its highest levels. The plants undergo maximum photosynthesis and will absorb maximum CO2 while releasing water vapor. On days with less than 100% sunlight, all of these levels correspondingly decrease and less venting is needed to maintain that perfect growing environment. Not all knee wall windows need to be opened for this system to work. In the winter, you may only need to open two central knee wall windows for proper venting. Once you understand this system, you can easily plan for the day by the weather forecast.
SunCatcher understands that not all folks can dedicate the time needed to manually operate their greenhouse. That is why SunCatcher has worked with GrowerNode™ Greenhouse Automation of British Columbia, Canada, to develop a complete automation system so a SunCatcher can be monitored and controlled from anywhere in the world via PC, tablet, or mobile device. You can track temperature, light, soil moisture, etc. and make operational changes to your vents, lights, and fans while at work or on vacation! You can add cameras, alarms, and smoke monitors for the utmost security.