The geodome year-round, winter greenhouse differs from ordinary greenhouses in that it utilizes a combination of innovative systems to harvest solar energy for both heating and cooling. These passive solar greenhouses are designed to accommodate heat-loving plants in the summer and cold-hardy crops in the winter with no or little need for heating or cooling (depending on the climate). Our value of "living lightly on the earth" is reflected in how efficient and simple each and every system in the geodome is. We encourage and support minimal use of fossil fuels with this clever design as well as have systems that are dual purpose, providing heating benefits in the winter and cooling in the summer. Nothing is wasted.
In the winter, the geodesic dome greenhouse is designed to capture and store the heat of the sun during the day and slow down the heat loss overnight. The following is an overview of this principle in action:
Capturing Heat During the Day
1. ABOVE GROUND POND:
Ever thought about replacing a propane heater with a pond of water? We've done the research and discovered the amount of water needed to replace those heaters. The pond is the key feature that allows the geodome to grow plants year-round. In the winter, the dark, metal surface of the pond absorbs the heat of the sun all day long and releases the stored energy at night to keep the geodome warm.
2. CENTRAL AIR SYSTEM:
When the interior of the year-round greenhouse is hot during sunny winter days the central air system, also called an under soil heating and cooling system, heats the soil. The central air system moderates soil temperatures so you have multiple, long windows to sow seeds and the opportunity to grow crops all year. In winter, the warm air inside the Growing Dome is drawn through pipes buried in the growing beds by the means of a solar powered fan. This helps to keep the soil in the growing beds warmer, thus increasing plant germination and growth. This soil heating system in our solar greenhouses is entirely free, as it uses the energy of the sun.
3. GEODESIC DOME SHAPE:
The shape of the passive greenhouse mirrors the path of the sun, so no matter what the sun's angle there is always direct sunlight entering the structure to heat it up.
Preventing Heat Loss at Night
1. POLYCARBONATE GLAZING PANELS:
This solar greenhouse is covered with energy-efficient, insulated twin or multi-wall polycarbonate glazing panels. These panels slow down heat loss through the transparent portion of the geodome.
2. NORTH WALL INSULATION:
Two fifths of the north wall of the geodesic dome is covered with reflective insulation panels. These panels act like a blanket and help to slow down the heat loss at night. It also traps the low winter sunlight and reflects it onto the surface of the pond to heat the water.
3. WALL INSULATION:
The outside walls of the growing beds in this year round greenhouse are insulated to prevent heat loss to the outdoors and keep the soil beds warmer.
4. FROST SKIRT:
There is an insulated frost skirt buried around the perimeter of the geodome to prevent frost from penetrating in and under the structure. With these unique systems and the geodesic dome greenhouse design, we create a structure that allows cool weather plants to continue to grow throughout snowy, cold winters. In very cold or cloudy climates the solar energy can be augmented with the use of a small greenhouse heater, which can be thermostatically controlled. We calculate that the geodome needs only 1/3 of the amount of heat required by conventional green houses.