Hi KK,
I use Phresh Hyper Fans. They allow me to adjust both ends depending on what's taking place in my tents. That's the idea behind the controllers. You essentially can manage your environment with a dial. The initial investment is worth it. Buy quality products. They come with warranties and overall last longer. And hey, if they don't, they get replaced.
Here is my example:
I have a nursery/vegetation tent in which I use an 8" fan turned down low. I don't currently use an intake fan for this tent as the exhaust sucks clean air in efficiently through the opened vent at the bottom of which I have ducting running to, which goes outside my house. Also, I only have 800w of T5s (all blue light, 4100k) at most, usually only 400w at any given time, so heat isn't an issue. I don't need a carbon filter. My plants don't smell at all in veg, unless you get up close and give them a rub.
My flowering room is different. I have a 5x9 housing a Gavita 1000w DE on a light rail. It gets warm depending on the time of year. I've only a couple of grows under my belt, so this is based on 12 months of experience (very limited, I know). What I learned is that the ability to control the fans with a dial makes a world of difference. I have full control of the environment. Both 8" fans. The exhaust is a silenced Phresh Hyper Fan attached to a Phresh carbon filter. Honestly though, my plants don't smell a whole lot. I did a little research into this, and apparently lack of smell isn't a bad thing. The buds smell beautiful when cured for a month or two.
If the room gets too hot, crank up the fans. Although I keep my light high. I never adjust it. I let the plants essentially grow into the space. I think growers tend to freak when it comes to heat. My plants haven't suffered any heat issues/stress thus far, that I've physically noticed, and I let it get nice and warm in there. Just make sure the light isn't directly focused too close to the plant/s. They'll tell you if they're not having fun under there.
If it gets too cold, turn the fans down and let the light heat the tent back up.
I've rambled here, so my apologies. What I'm saying is don't buy inferior products like cheap fans and things that you're just going to upgrade later. Do it right the first time.
Keep a monitor in your tent so you know exactly what's going on in there. Set your environment up for ideal growing conditions (this is also strain dependent, which is why sticking to one strain can make things easier inc. nutrients, watering etc.) and before you know it there will be so much green in there you won't know what to do
