I’ve been trying to dial in my environment for the last few day.
To recap, my initial tests were will all lights at 100% intensity, resulting in a total of 50 W per square foot. The fan speed was set to 5, the fan setpoint was 77F, and the AC in the lung room was set to 75F. After an hour or two, the temperature at the probe was up to 90F, I did not take a soil temperature reading. So I bumped the fan speed to 10 and it dropped the probe sensor to 88F. So, I installed a circulation fan and lowered the fan’s temperature probe to about 1/2 way between the soil and the light.
Once I got the dimmer wires connected to the controller, I was able to run the lights with a simulated sunrise/sunset. Running with a max intensity of 70% the max soil temperature was 86-88F (depending on which thermometer I use) after 9 hours. It then quickly cooled off as the lights began ramping down in the evening. The mother room was running at the same time, so I went ahead and set them so that the mother room runs during the day and the main room remains on at night. I’ve also lowered the AC in the lung room to 72F. So far it seems to be keeping up, in theory the 5,000 BTU unit should cool 1200 watts. I may also set my max fan speed to 6, but when I set it to 10 it was too loud.
I have been doing some mathematical modeling of the lights, as a way of helping me dial in my environment. The first thing I did was calculate the kilowatt hours (kWh) that are used in a day for both veg and flower settings. For veg, I came up with about 12 kWh with an average of 662 Watts. For flowering, I came up with about 8 kWh with the same average of 662 Watts. Both run a max wattage of 876 over 24 square feet, or 36.5 W/ft2 for half of the day cycle.
From there I was looking at DLI charts and noticed that at the beginning of the growing season in the spring, DLI was very similar to the end of the growing season in the fall. Based on that, I came up with some settings using an 18 hour day that uses a similar kWh as flowering. I settled on settings that gave me about 7.6 kWh with a max of 556 Watts and an average of 425 Watts.
I noticed one of the lights didn’t turn off at the right time, I double checked my timer and it should have worked. I was logging in at the exact moment it should have switched, so it may have just been a delay. I will see if this was a one-time issue. I also had my Bluefish set to the wrong time zone, so instead of having just the far red on, I had all the supplemental lighting on around 50%. That’s been fixed and I will be double checking everything during the next cycle using the early veg settings. No need to blast the clover cover crop with a ton of light before it has even sprouted.