1) True or False: Provided the exhaust is ducted so it is sucking directly from the canopy area, taking exhaust air temperature readings at the point of outflow should provide an accurate indication of ambient air temp/condition within a cabinet while eliminating erroneous thermometer readings due to radiant heat effects around the lights.
im not 100%, but i would imagine false. since the fan naturally will have a cooling effect on the air as it passes through the ducting. the air that comes from my exhaust ducting is colder than that inside my tent
That's kinda what I'm wondering about, yeah. I guess at a more microairflow level, small "chunks" of air are impeded by the duct walls and have more time to cool before exiting.
How do you figure..as that air is sucked up its shedding heat, as it goes down your ducting its shedding heat. The temp at the end point of your airflow would be highly inaccurate for maintaining temp inside your grow room/temp. You will think its like 72 when at plant level it would be considerably higher. The area you should be concerned with is what is it like at the top of the plants. If its say 80 there its lower as you go down the plant till you hit the ground. If you can keep the temp above your plant low then you can have any kind of light just about right on top of it.
I hear ya dude, just trying to get the light closer without spending more money...but once again I guess ya don't get anything for nuthin; then again the best things in life are free, so who the f&*% knows.
Closer the light hotter the air is...why because less airflow between the two. Simple. Heres a cool chart on distance for HPS lights. Thats why people have crazy cooling systems so they can bring there HPS as close as possible. http://forum.grasscity.com/attachme...-lights-plants-light_distance_chart_1__1_.jpg