So many great grows to read through, yet so little time! I breezed through this looking for info on your 400W CMH bulb but I definitely want to go back and read some more!!
Regarding the 400W CMH what would you predict the differences in temp would be between the 400W CMH and 430W HPS in your current setup, assuming you made no changes but the bulb.
I'm currently running 250MH mother chamber right above my flower chambers (actually 2 flower chambers) but when I plug in one of the 430W HPS it whacks everything out temp-wise even with massive air changes and such. Before I resort to buying a used portable AC unit, do you think I can get my temps down from 86* by converting over to the CMH bulb? Each chamber is 48"w x 35"h x 17"d or roughly 18cu ft per chamber.
Any info would be most welcome!! I like the lumen and spectrum data on this bulb, just hoping the temp side of it is there too!!
peace bro!
best to my knowledge, the CMH burns hotter than the HPS, tho I have nothing to compare it against (no HPS)
getting my 400w cmh and 250 mh in a single cabinet was a bold move, and is more complex than my deceptively simple pics show.
I could run either the 400, or the 250 by itself with no problems, but if i ran them
both, the combined heat from them and the two other cabs was too much for my little a/c unit. Firing up the 250 400w combo made my temps rise from 67 in the room to 85 in the room in just a matter of 90 mins or less.
not wanting to spend money on a larger, energy hogging a/c unit, i wanted to see if i could use some applied engineering to solve my conundrum.
i wanted both lamps running, but didnt want to pay out any more $, so i got smart and turned to technology for the answer.
from racing technology, i utilized the concept of CAI (cold air intake) by using ducting off the sides of the cab to act as a 'scoop' to pick up the coldest air in the room, right off the floor. (cold air always sinks to the lowest point in the room) my exhuast fans for this particular cab generate enough negative pressure to compress the air as it enters the duct, cooling it an additional 2 degrees. but it still wasnt enough, and here's where i got tricky... i made a thermocline out of my grow room.
a thermocline exists in any body of gas or fluid that has temperature differences. thermoclines are responsible for the weather, ocean currents, the jet stream, and very interesting sonar properties in the ocean. but for growroom purposes, a thermocline is where the air in the upper portion of the room is a great deal warmer than the air in the lower portion of the room, by several degrees. I was able to do this by carefully positioning the fans inside the room to direct heated air up, and a/c air down to the floor. the result is that the temp close to ceiling level is 78f, the temp on the floor 70f, the cold 70f degree air keeps the cab interiors at a balmy 79-81f.
complicated explanation for a simple concept.