Book Info
Dan Chiras: The Chinese Greenhouse: Design and Build a Low-Cost, Passive Solar Greenhouse
Problems of conventional greenhoues
- no insulation
- unnecessary heat loss to surrounding → surface area to big
- above ground area too big, windy take away the heat
- too little thermal mass to store heat for a prolonged period
- orientation not properly positioned, receive not adequate heat or excess heat across seasons
Benefit of Chinese greenhouse
- less voluminuous or spacious: save heating energy
- better than conventional greenhouses in all the above factors
Factors when considering building a green house
- insulation: soil is not a good insulator, good insulation is needed across the whole structure and surrounding environment
- from the ceiling, an extra layer of clothes might be needed at night to prevent loss of heat to prevent excess heat entering the greenhouse
- to the surrounding structure, moist could reduce the insulation significantly to insulating materials like cellulose
- water drainage, underground pipe and drains are needed to divert water elsewhere from the greenhouse, to protect the plants from getting mould to prevent excess pest problems, also to protect the structural safety
- thermal mass, a big mass is needed, but too big means high cost, it is to stablize the temperature inside the greenhouse
- orientation, facing south is good, east west and north should be sheltered, mind the difference between actual north and magnetic north
- cost of construction
- climate of the location, freeze line, frost free period, amount of annual sun light
- backup heating is needed, ventilation for excess heat is needed
Note: solar hot air collector, can be used to heat the air at home, it is cost friendly, as it only use fan and sun, with no use of natural gas, suitable for home