Heat calculation and projection

Even though I don't grow in the warm months (Ohio) I'm still having heat problems. Of course, the issue with heat is always how much cool air you can bring in (and how cool), and how well you can dispose of the hot air. My grow is in a closet in a bedroom, and of course I could solve the problem by just opening windows. But it is also living space and I don't want it to get that cool.

So here's a hypothetical. Assume a space of 3.5 ft by 3.5 ft, and 6.5 tall. Ventable in and out from the space above to the room outside. Do not assume a source other than ambient (in the bedroom) air, nor a place to vent other than back into that room. If the ambient temperature in the bedroom can be kept to 70 (maybe a few degrees lower), can the grow space accommodate a 600w hps and keep foliage 78 or lower?

my ambient temp is about 70 and with my 600w it stays about that temperature..like 78ish..also in a closet in a bedroom.

Apt or house....? Anyway you can vent the heat out of the closet into the attic?

Air cooled i feel like I can keep 1000w within around 10-15 degrees of ambient. I know thats a big range, however I'm not even bringing in cold air, just air from the room outside. Basically exhausting and pulling from the same outside room. If you are able to exchange from outdoors, or another room, you can probably manage even better than this.

I've not tried this in the hot summer, but with ambients at around 68 similar to you.