Hi All,
I wanted to ask about feasability. I have a 14ft x 8ft greenhouse at home, and i am looking at the best way for me to climate control this room. I have worked out some Insulation but it still gets hot / cold in there, so i want to see if i can use something like an Arduino to better manage temperatures.
I know there already exist oil based, electric etc heating systems but i owuld like to keep it as cost effective as possible. I thought given the temperature within the greenhouse gets hot during the day (30 - 40 Deg C) and cold at night i could look at thermal bodies. My thought was i could use a car radiator in the greenhouse, connected to a small (200L canvas tank) inside the greenhouse. I would put a temperature sensor inside the tank, one before the radiator (water line), and one after the radiator (water line) in addition to a temperature and humidity sensor both inside the greenhouse and outside.
The idea woulld be that the system looks at the temperature inside the greenhouse, and outside the greenhouse to determine if it is hotter inside the greenhouse, it would then circulate water through a small pump to the radiator, and measure the temperature before the water goes into the radiator and after it comes out. provided the temperature increases after the radiator it would keep running, and if the temperature stops increasing it would stop the system running (if the temperature of the greenhouse is hotter than outside).
As the temperature drops (below a preset) it woud then pump the water from the tank, into the radiator and run the fans to increase the temperature in the greenhouse.
Do people think this is feasable, and has anyone done anything similar to this. I thought PWM could be used to control the speed of the fan, and even the pump, in addition to having an ethernet shield manage temperatures, and device(s). Ideally i would set it so that it tries to achieve a set temperature, but if it cannot, it does not just aimlessly try. For example say i set it to 30 Deg C in the greenhouse, and the water temperature is 29 Deg C, and it won't continue to reduce heat after the hot water passes through the radiator, it would eventually give up, especially if the temperature through the radiator increased.
The bonus would be that during the day, the radiator would try and balance heat within the greenhouse, and absorb the excess temperature, but during the night / colder period it would release the excess temperature in the radiator to the internal greenhouse environment.