I'd say both. Also, insulating will help you more during winter than summer. When I grew in a tent, in the garage, I shut the growing down for the summer. It's so much easier and cheaper battling the cold then the heat IMO. Good luck sir.
Yes. I had the lights way too close. It's since been corrected. I'm 18 inches from the canopy now and they have never looked better. This next round I'm going to keep the lights at 8 feet and let the ladies stretch real good.
I just bought the 300w framework for a 3x3. Dan is making it a bit wider and longer so I can slip my Mars blurple into the center of it. Timber rules. It's my third kit from him but the first kit I've had him build the frame for. I'm patiently waiting....lol
I'm at 50w per sq/ft with my COBs and I've had to back the lights off a bit. My buds are incredibly frosty but there's slight bleaching in the top fan leaves.