Room getting too hot with both lights on

[RandyL]

I have a 4 by 8 tent all set up, it has been vegging 9 indicas under a 400 MH, with a 6" ducted inline fan (about 200 cfm) pulling air through the lights from outside, and temperature was always maintained well. I use the Jupiter 6 vented hoods.

After 14 days in veg, the clones were rootbound in their small 6" pots, so yesterday I did all my transplanting into 7 gallon pots with Sunshine Mix #4.

Because of the size of the pots, I had to hook up and turn on the second light, and since I didn't have a second 400 watt ballast, it got the 1000 watt MH.

This was too much for the 200 cfm fan, so I swapped in the 435 cfm Vortex 6". It does a good job of pulling air through both hoods, and the hoods are a bit warm but not hot to the touch, but the room still gets hot now. I have CO2 running, and temps today were hitting 92-95 in the tent at plant level.

I even took the step of shutting down the CO2 and having the exhaust fan run all afternoon, but this only maintained the temperature and didn't drop it much.

Due to the layout of the apartment, getting A/C into the room isn't very practical. A friend has a portable A/C unit I could use, but due to the circuit breakers and power load in the apartment, that would be pushing it if the A/C drew over 500 watts. It was a warm day, about 82 degrees outside today, so that definitely didn't help.

Any suggestions? I think 92-95 is too damn hot even with CO2.

I'm hoping for cooler weather soon, because in flowering I'll be running 2 1000 watt HPS bulbs in this room.

 

[MedicalNeed]

You could have the dark period during the hotest part of the day to limit heat input.

 

[DrOfDank]

For the size of your tent, you need air moving out of that tent at about 700-800 CFM. I'd suggest two of those 435 cfm Vortexes.

 

[RandyL]

Are you saying the 435 cfm 6" vortex pulling air through the reflectors needs to be 700-800 cfm to cool the lights themselves, or are you saying that the 435 on the reflectors is ok and I need another 400 or so cycling the air in the room itself?

These Jupiter 6" reflectors are sealed, so the air cooling them and the air cooling the room itself are 2 separate things.

Jupiter 6 Hood | New And Used Grow Lights

If I had the air in the room being constantly exchanged, that ought to help the temperature problem but then I wouldn't be able to run the CO2.

My carbon filter in the room is a Can 66 filter, and its fan is one of the 6" inline ~200 cfm units.

I have 2 of the 8 event per day programmable timers handling the exhaust / carbon fan and the CO2. Every 2 hours (more or less), the exhaust fan runs for 15 minutes, then after a 1 minute gap, the CO2 turns on for 5 minutes @ 3cfm. Then 2 or so hours later the exhaust fan cycles the air again.

But that gives the air in the tent a lot of time to heat up. Some redesign may be needed.

The tent itself is 4 by 8 by 6.6 feet tall, for 211 cubic feet.

 

[GeorgeFoster]

Are you saying the 435 cfm 6" vortex pulling air through the reflectors needs to be 700-800 cfm to cool the lights themselves, or are you saying that the 435 on the reflectors is ok and I need another 400 or so cycling the air in the room itself?

These Jupiter 6" reflectors are sealed, so the air cooling them and the air cooling the room itself are 2 separate things.

Jupiter 6 Hood | New And Used Grow Lights

If I had the air in the room being constantly exchanged, that ought to help the temperature problem but then I wouldn't be able to run the CO2.

My carbon filter in the room is a Can 66 filter, and its fan is one of the 6" inline ~200 cfm units.

I have 2 of the 8 event per day programmable timers handling the exhaust / carbon fan and the CO2. Every 2 hours (more or less), the exhaust fan runs for 15 minutes, then after a 1 minute gap, the CO2 turns on for 5 minutes @ 3cfm. Then 2 or so hours later the exhaust fan cycles the air again.

But that gives the air in the tent a lot of time to heat up. Some redesign may be needed.

The tent itself is 4 by 8 by 6.6 feet tall, for 211 cubic feet.

What someone has suggested is you need MORE CFM's in your fan for the size of your tent.....tent area has nothing to do with sealed vented hoods....as said it's is your GROW area that is too hot.

on that 1000w ballast do you have a dimmer switch? try it at 75% or even 50% until you can get enough flow to vent the tent properly.

Just a thought, hope it helps.

 

[RandyL]

The ballasts are the old coil & core style, no dimmer switch.

 

[GeorgeFoster]

get rid of the 400 then until you can vent more or lose the 1000.

Another option is ad a cool mist humidifier


to be honest 2 400w HPS would do wonders in that 4x8

Don't get caught up in I need 2 1000's.
My room was 7x9 with 2 600 recently reduced to 7x7 and I produce some nice weed, lots of growers here put out awesome dank mega buds with 400's

 

[RandyL]

I rerouted the intake / exhaust ducts, with one 200 cfm fan blowing into the tent, and the carbon filters' 200 cfm blowing out. With that, the temperature has slowly dropped over the last few hours, it is in the high 80's now.

I'll have to get the 2 timers tonight and reprogram them to manage some CO2 into the room while still keeping the room temperature down. It'll take some experimenting to balance the CO2 time with temperature control.

 

[Flodas]

Maybe i can help i usually have a fan blowing straight at the bulbs. Put ur ballast outside the tent or the area if u can. Put in an air-socket so the air distributes everywhere.

 

[RandyL]

Yes, the ballasts are outside the tent but in the room, and there's a bidirectional oscillating fan in the tent. It goes side to side and up and down both together.

Temps in the room today have stayed in the low to mid 80s, I reprogrammed the vent fans and CO2 timers to give 1 hour of CO2, 30 minutes venting, repeat.

My timers can only program 8 events per day though, so with lights on at 6 am and off at midnight, I run out of events around 7pm, so its vent fans on from about 7 to midnight.

I guess the thing to do then is to plug a programmable timer INTO the programmable timer, so when one runs out of events, its last one stays ON, then the other one starts its on and offs until dark time arrives!

The second timer is ON, on its first on-off cycle, while the first one does its on and offs. I think that would work.

How hard could it be to make a timer with more than 8 programmable events? Just a bigger memory chip if anything.

 

[MedicalNeed]

I hear you on the limited events Randy, I think it comes down to price/cost of making.
I suppose there is a FINE line they try to nail inbetween.


Good Luck!

 

[RandyL]

They should at least have the option of a 12 or 16 event timer, maybe charge a little extra for it.

 

[Mattdaddy]

Sounds like too much light and heat , and not enough cooling for that tent. You really need to be lower than 85 degrees to prevent other issues . I like the idea of going to 400's like Heady suggested . Keep your ballast out of the tent , and lights at night only . I know a lot of growers are pro co2 , but I'm not . With good air exchange you should be able to eliminate the co2. Good luck !