I have made a mistake. Been kicking around the idea of getting a new light, since pretty much right after buying the last two during black friday/cyber monday last year. True to my consumerist brainwashing, I decided that I should take advantage of the sales again this year. That makes sense. The mistake was buying something I hadn’t thoroughly researched first, which is rather uncharacteristic of me.
I bought a 1000 watt DE kit that came with MH and HPS bulbs, dimmable ballast, and air cooled hood. I’ve never looked into DE HPS beyond the headlines of better output, coverage, spectrum, and penetration. Having ran air cooled HPS plenty before, it seemed a no brainer to get an air cooled hood.
Off to the webz I went to learn more about my shiny new toy, only to find out that air cooling a DE HPS directly is bad. Quick look at the hood that I just ordered shows the bulb in the direct airflow. Attempted to contact customer service to change the order to a single end fixture, but it was too late. Oops.
I found a youtube vid with par measurements of a similar hood, and it dropped output by around 35% when air cooled at full fan speed. 35% is too much to lose.
I’m going to try to see just how slow I can run a fan through this hood to keep the top cool enough to mount close to the ceiling. I could take the glass off, and just run it open, but would rather try to cool it to get it closer to the ceiling.
Even with 35% losses, it will be a considerable addition to flowering lighting, and will allow me to grow much taller plants. After a couple cycles, it will likely get replaced by something much better. Maybe something like this when I get somewhere with higher ceilings:
Looks sweet for flexibility. It’s able to run MH, HPS, and CMH, with different reflectors available.
Anyhow, does anyone here have any solid info or experience with negative effects of directly air cooling a DE HPS? If I can’t get adequate cooling of the fixture with minimal airflow, I may just run it open, without the glass, and keep it further from the ceiling. Is that a bad idea to be avoided, or would it probably be alright?
Thanks for reading my book. Just doesn’t seem to be much discussion on the topic other than don’t do it unless you have a hood that doesn’t pass the air over the bulb.