drastic increase in temps past couple on times?

Hi there. I have 2 400w hps in xtrasun 64 ac hoods with a 400cfm fan pulling through them.
I just got these hoods a couple weeks ago and up until the past couple nights its been sitting right around 81 (night is lights on for me). And rhese past two nights my thermometer has told me that at some point its been hitting 98!!

The room where intake is from has been sitting in the hight 70s because its been kinda hot outside, but I can't see it being 20 degrees hotter than usual outside at night. And normally the air whete intake is from is in the low 70s.

As fAr as I can tell I havent sprung any air leaks around my hoods either. So my questions are does anyone know if it is really just the outside temps doing this or if it is most likely something else?

caveman117 said:

Hi there. I have 2 400w hps in xtrasun 64 ac hoods with a 400cfm fan pulling through them.
I just got these hoods a couple weeks ago and up until the past couple nights its been sitting right around 81 (night is lights on for me). And rhese past two nights my thermometer has told me that at some point its been hitting 98!!

The room where intake is from has been sitting in the hight 70s because its been kinda hot outside, but I can't see it being 20 degrees hotter than usual outside at night. And normally the air whete intake is from is in the low 70s.

As fAr as I can tell I havent sprung any air leaks around my hoods either. So my questions are does anyone know if it is really just the outside temps doing this or if it is most likely something else?

Click to expand...

I run two 600's in cool tubes with a 440 cfm fan blowing through them pulling air from within the room venting to the outside. my flower room is 10'x16' with a 15,500 btu A/C in it. My temps hit 84 degrees with the A/C set at 71 degrees while the lights are on at night time. its been in the mid 40's at night.

You are dealing with radiant heat from your light. Are you pulling cool air into the grow area? are you pushing hot air out of the grow area? Another question.. are you pulling air through the light or pushing it?

Thatnks for the reply!

Currently I'm pulling air through the hoods and out of the flower area to the fan and then pushing it outside. I'm also using this same exhaust to vent that room through the hoods because when I upgraded to ac hoods I took out the old fan and ran the duct through the same hole whrre the old fan was. As for intake there are two 8 inch passive intake vents at the bottom of the closet.

caveman117 said:

Thatnks for the reply!

Currently I'm pulling air through the hoods and out of the flower area to the fan and then pushing it outside. I'm also using this same exhaust to vent that room through the hoods because when I upgraded to ac hoods I took out the old fan and ran the duct through the same hole whrre the old fan was. As for intake there are two 8 inch passive intake vents at the bottom of the closet.

Click to expand...

It's great that you are pulling air through the lights! I noticed in my room that it runs warmer when I use the same fan for the lights and for removing air from the room. I think it is because there is warm air going into the lights so they don't cool as well. When pulling air from outside through the lights and using a second fan to evac the room the temps were considerably lower. Something to consider!!

Hmm thanks for rhe advice! I'll see if I can get rid of a 90 in the ducting and try duct outside on the other end too.

98 degrees is extremely hot. Could your fans possibly be plugged in to your light timer by any chance? It sounds dumb but I've seen it happen. You have nearly a 20 deg. increase, the fans must be shutting off.

Those are quality reflectors. A relative uses them. Nice. But air cooled lamps radiate heat. Insulated ducting helps big time. Pulling cooler air from a spot other than the actual growing area helps too. The inline fan(s) used to pull out the hot lamp air is a big heat radiator. Place that outside the grow area is a big plus.Your basically a slave to outside temperature fluctuations on a daily basis no matter what setup you have without actual air conditioning units and dehumidifiers. Keep in mind these are expensive to run. Especially on top of the total wattage of lamps and fans. Its a trade off. Where iam at in Michigan the cooler months of fall and cold ass winters make growing indoors with heat radiating lamps whether cooled or open much more easier than summer. In the warm months ac is pretty much necessary. How can you cool lamps and /or the room if the air your trying to cool with is as warm or warmer than the air that your tring to remove or replace? Now you see why growers with multiple lamp setups forego all of that headache and run sealed rooms and use appliances and units to controll the atmosphere 24-7. No matter where u live or the climate outside ...your garden has perfect conditions always. The only drawback is it is very expensive to purchase this equipment and even more expensive to run.