A discussion of how we can increase the security our local food supply at a time when rising fuel costs, climate change and political turmoil make it particularly vulnerable. As seen through the lens of the Imani Gardens, located at 1680 Pacific Street and 87-91 Schenectady Street.
Travis Frazelle and I spent a lovely Sunday morning moving the solar panel from the aquaponics system in Imani I to the new greenhouse in Imani II. The aquaponics system goes quiet in the winter while the greenhouse scene comes to life so we figured the solar panel would be more helpful with the greenhouse. We also removed the pump from the pond for the winter and moved the two six volt deep cycle storage batteries to the greenhouse.
I salvaged a 12 volt fan from an old computer and hooked it up to the batteries (connected in serial to create 12 volts) and it works fine, as you can see below.
Next step: bury 4 inch plastic drain pipe along the sides of the greenhouse. We then tie 4 inch aluminum duct along the ridge at the top of the greenhouse and connect it to the buried drain.
We'll connect the 12 volt salvaged fan, controlled by a attic fan thermostat, to the front of the top tube.
We will cover the floor of the greenhouse with thick plastic, then sand and finally gravel.
Finally we'll place donated six 55 gallon barrels filled with water on top of the buried drain pipe and paint them black. These barrels serve as the base for our planting trays in the greenhouse. These also store heat captured during the days.
Once the system is all in place, the fan will move warm air at the top of the greenhouse down into the soil under the barrels. The fan will only come on when the temperature reaches 60 degrees at the top of the greenhouse. The black barrels will also absorb heat directly from the sun. The heat will then dissipate slowly over the cold nights to keep our greenhouse warm.
We'll also be installing a thermometer to measure both indoor and outdoor temperatues to record the temperature differentials we are achieving.
At the very least, we should be able to grow cold hardy plants such as lettuce, kale, cabbage and brocolli during the cold winter months.
Net cost: about $175.