Tuesday, April 11, 2006

Humidity Control Settings

In the last two graphs shown, the inside relative humidity (RH) did not reach the control setpoint. (The control setpoint is at 85% inside RH.)

Sunday, April 09, 2006

April 9, 2006 (Settings are same as for April 5, 2006 Graph)


Wednesday, April 05, 2006

Comments on the April 5, 2006 Graph

The heaters are set at 60 deg F, with a hysteresis of +/- 1 F deg ( The heaters turn "on" at 61 deg F and turn "off" at 59 deg F).

The vent fans are set at 80 deg F, with a hysteresis of +/- 1 F deg.

Note the "steps" in nutrient solution temperature, coinciding with nutrient solution pump cycles. Increases of up to 9 F degrees (on sunny days) have been observed in Late March and early April. Since the nutrient solution storage tanks are located inside the greenhouse, this heat is released in the greenhouse (when greenhouse air temperature drops below that of the nutrient solution).