Experimental cold grow
- Thread starter loke
- Start date
Man o' the green
Active Member
I have a grow box in a spare room that has no climate control. The box is small enough ( 3x4x4' ) and there is enough light wattage ( approx 300W ) to keep the temperature into the 70s when the outside temperature gets close to freezing. The problem with this enclosed design like most, is not cold, but heat. The majority of the time, there is too much heat built up in the box, and a small A/C unit takes over. This unit is part of the grow box, and blows the hot air into the room. The enclosed area also uses much more reflected light, and keeps the humidity high during the dark cold periods. ( good or not, I'm not sure )
Always add lights for heat if possible. It's a much better use of energy and safer than heaters. Because lights put out so much heat, it's easier to remove the heat ( with A/C ) to the right temperature year-round than add heat with a heater. I find that simple ventilation of the box creates an unpredictable temperature.
This A/C method works fine until flowering when the lights off period lets the box get cold. I've only run one flowering cycle through the winter with very cold dark periods, usually during the day when it's warmer out. However, I didn't have any problems with cold "nights" during flowering. ( 45 degrees was approx the minimum temperature ) I have no data, but it appeared that growth was slowed down, and flower development was not as robust. I will say that with no climate control in the box, "days" above 82 or below 68 gave me poor results.
My impression from my experiments is that you must have good temperature control for worthwhile results. So my answer to your question is no, I would not attempt a grow in that environment without significant modifications.
Always add lights for heat if possible. It's a much better use of energy and safer than heaters. Because lights put out so much heat, it's easier to remove the heat ( with A/C ) to the right temperature year-round than add heat with a heater. I find that simple ventilation of the box creates an unpredictable temperature.
This A/C method works fine until flowering when the lights off period lets the box get cold. I've only run one flowering cycle through the winter with very cold dark periods, usually during the day when it's warmer out. However, I didn't have any problems with cold "nights" during flowering. ( 45 degrees was approx the minimum temperature ) I have no data, but it appeared that growth was slowed down, and flower development was not as robust. I will say that with no climate control in the box, "days" above 82 or below 68 gave me poor results.
My impression from my experiments is that you must have good temperature control for worthwhile results. So my answer to your question is no, I would not attempt a grow in that environment without significant modifications.