Lucky Luke
Well-Known Member
The exhausted air will not even be close to causing a fire. If you can upgrade the grow space you should spend the money there and upgrade to a light that suites that size at a later date.Hi Everyone... Just wrapped up my 4th run and have observed the performance from my setup for each. I am using a 4' (wide) x 3' (deep) 8' (high) [ 12 sq ' ] storage / closet room. I have a 4" exhaust fan and carbon filter at the top of the room that exhausts the air up through the ceiling to a location approx 10 - 12 ft away from the room into the attic. For intake I am only using passive intake as the door to this room sets right next to a window and has sufficient venting at the floor level that keeps a negative pressure and any hints of odor under control. All seems to be ok on the venting and air movement as far as I have seen. Now on my first grow I flowered with a standard open wing hood 150 watt HPS as main light and also added in ( 2 ) Mars Hydro 300 LED [ approx 135 real watt per light ] a little later , which totaled around 420 watts. The first yield was massive almost 9 ounces under these conditions. However I thought that the temps brought on by the open hood and HPS were a little much for the size of room and decided after to switch out the 150 watt HPS for a Mars Hydro LED 600 [ 280 real watt ] giving me even more wattage for the second run.
However after the second run temps were allot easier to control since the LED run much cooler but the yield on run #2 was almost minus half of the first run bringing in only a little over 4 ounces even though I was using more lighting wattage on the second run. I chalked this up too perhaps genetics and simply set up for run #3 using the same genetics as the first run and again under the all LED lights yield was not even close to the first .. around 5 ounces again with buds much smaller than I had seen using the 150w HPS. So I carried out this last run again using the 3 LED lights and No HPS and again noticed the buds are smaller and yield not even close to what I got from the first run using the HPS as main light and LED as side lighting. So now I am under the impression that HPS will produce larger yields for me than LED ..and seemed to do even better when adding in some LED for supplemental lighting with it. So armed with this info , I have decided to go back and try my next run with HPS again since I had such a great turn out using that 150 watt first time. But I figure if I got that good of a turn out with just 150w , I imagine I can improve that even more by switching that 150w out for a 400w or 600w " Air Cooled " hood. Since I had a tad bit of heat issues with the 150 in a open hood I want to try running my exhaust through a closed hood and exhaust into attic as before.
Which brings me to my question. How hot is the air that is being exhausted off of a 400 watt HPS ? I would imagine that it can't be hot enough to start a fire ( but want to be sure ) since it will be being exhausted into a dry attic that I can not monitor. I was thinking moving to a closed air cooled 400w hood would be a perfect upgrade from my open hood 150w for this room. But if the answer is " NO " the exhausted air from the 400w light will not be hot enough to create a fire hazard in the attic then another question arises with the 600w if I can go with 400w w/o any fire hazard , how about a 600w ? My 2 biggest concerns are #1 fire and safety and # 2 being able to keep this size of room cool enough for whatever light I will be using .. which has left me torn between upgrading a bit to a 400w or upgrading allot to a 600w , of course with the small price difference I would rather go with the 600w but I don't want to over upgrade and cause further issues with possible heat or even worse safety issues. I was only leaning toward the 400w cause I can dim it down to the 150w that I was using in the first place should anything not go as planned , however the 600w even on the lowest dim setting would be 250w and that is still 100 watt more than any HPS I have used in this room before. Any suggestion and opinions are highly appreciated ..Thank you all in advance for any input.
ANC brought up a scary thought..ive never seen a Lamp explode and if it does what he is saying then that's kinda scary.
Mars and viper etc will veg OK but in general they struggle to get any density. But there are legitimate LED lights that compete favourably with the HID. They don't get quiet so hot.
Unless your running known clones then its hard to compare weight per run due to the different phenos and vigour etc
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