indoor Indoor Grow... Temps too Hot... A/C or Not

TAG>>  New Indoor Grower
 
Greeting All. My question is about temp and humidity, and should I spent a lot of time and effort controlling these two factors.
 
Basics>>
Currently three plants in 3 Gal cloth pots... Ghost, and two Tasmanian Habanero.  Have 9 more pants planned.
 
VIPARSPECTRA 700 LED running FULL.
Hydrofarm Phantom CMH 315W 
 
4x4 Gorilla Lite tent. 6ft 7in.
 
 
I've been fighting temps in my indoor grow for the entire summer. In the early spring I set up a tent in the spare bedrooms upstairs in the house. It was difficult to keep the tent temps below 90+ DegF. I tried venting the tent directly into the spare room with exhaust fans and relied on the house A/C to remove the heat from that room. That didn't work. Not even a little bit. Temps remained high, and the humidity was low at 35%.
 
Next I tried venting directly from the tent to the outdoors through a window, hoping that the house A/C (A/C set to 76degF) would cool the tent. This was a little better, cooling the tent down to the mid 80's, the humidity was still at 35%.  (normal A/C expectation).
 
Then I moved the entire system tent to the lowest level in the house. During the summer (now) while we have the A/C on, the lowest level remains cool at around 68 degF. This helped drop the internal temp of the tent to the mid 70degF. I loved this temp, but the humidity was still low at 35%. Note that this system DOES NOT vent outdoors.
 
I added a humidifier to the tent. The humidifier brought the Relative Humidity out of the dirt (30-35%RH) to around 60%RH.  This was progress !!
 
But now it is late August... in Minnesota the outdoor temps have been a little lower than normal, and that makes my Wife want to turn the A/C off. Turning the A/C off in the house has a dramatic affect on my grow system. Now there is less separation of temps between the upstairs and downstairs. The temps on the lower level are increasing in relation to the average house temps so the internal tent temps are increasing quite a bit. The internal tent temp in the lower level of the house without the A/C running are increasing to the upper 80's to low 90's. Humidity has remained in the 50-60% range with the humidifiers running.
 
The basic question is.... without regard to investment payback.... Is indoor A/C worth the effort ???
 
Thanks all,
 
Jeff
 
 
 
 
 
How many cfm's is your exaust fan pulling? In sizing a growroom fan it needs to exchange the air every min to have a slight cooling effect. so you would need 4×4x7'=132 cfm fan.Can you put your lights in a vented hood? with the hood you pull the heat out and leave the humidity in.
 
Can you pull your fresh air from under your house? Maybe get into the crawl and disconnect a heater vent and attach flexible ducting to the tent. 
 
How many hours of light are you giving them? Are you running your lights in the cool of night?
 
hogleg said:
Can you pull your fresh air from under your house? Maybe get into the crawl and disconnect a heater vent and attach flexible ducting to the tent. 
 
How many hours of light are you giving them? Are you running your lights in the cool of night?
 

This is all good stuff....assuming you have an "under the house", that's where the coolest outside air is. Lights at night make a big difference too.
 
Thanks all. 
 
Biggy... I have 400+ CFM available. I can suck the air out of the tent plenty fast (maybe a few small animals too). The problem is that the air coming back in to the tent to replace the removed air is at a very low humidity. And now that the house A/C is off, that refresh air is also warmer.
 
Hogleg... I don't have a crawl space. Best option is what I am doing now... using the lowest level in the house to get the coolest air. I am running the light early in the morning, but the internal house temps don't really vary that much during the 24 hours cycle.
 
So back to the original question..........  Does direct A/C really make that much difference, or can I just forget about controlling the temp and humidity ?  Will my plants grow well enough in high heat and low humidity ??
 
Jeff
 
p.s.  I'm planning on the late fall and winter season to pull the cold air (20degF to -15degF) inside to cool the grows. For next summer I will buy an A/C unit to keep the tents at ~80degF and 60-70% RH.
 
 
 
 
 
 
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