|I live in southeast NC and recently attached a hothouse onto my home. There are tropical plants I want to grow and winter in the hothouse. What is the best way to heat and cool the hothouse ? The roof is clear fiberglass and walls are green and clear fiberglass. It gets very hot inside on sunny days and too cold for tropicals in winter. So far,it has one outside door,two windows,and a door to the house.
|Most greenhouses encounter similar problems. Heating will depend on the least expensive fuel available locally as well as on whether or not the heating system for the house can be extended to accommodate the extra area. Your local utility companies should be able to help you compare the costs for the different types of heat. You may also be able to insulate it somewhat with an additional layer of clear plastic to help with heat retention at night. Many attached greenhouses can be used as a heat source for the house during the day by running a small fan to move the hot air into the house. You may also find it necessary to use a roof vent and automatic vent opener, activated by temperature, to help control the overheating. This would be positioned to allow for cross ventilation from a low level incoming vent. In warmer months, the greenhouse can be cooled to some extent by the roof venting, shade cloth or whitewash stretched over the ceiling and sides, and also by the shade of a deciduous tree planted to the west or southwest side. In some cases a greenhouse may also be cooled by an evaporative cooler or even by air conditioning. During the summer, many greenhouses are emptied and left with their doors open because they are too hot for the plants. This is a good time to repair, clean and disinfect it prior to bringing the plants back in again in the fall. Finally, you may want to invest in a min-max thermometer to help you track the actual temperatures in the hothouse.