I run a small 60-seat theater-cafe building in Los Angeles (specs below). When we run the stage lights (say, twenty 500-watt instruments at a time) in the summer, we canâ€™t keep our little auditorium from heating up to 80 or 85 degrees or more during shows. Audience members give up and leave, sweating and complaining. The actors havenâ€™t yet passed out onstage but they sure arenâ€™t happy. Last week we had a new 5-ton HVAC rooftop unit (compressor/heat pump) installed, but that STILL isnâ€™t enough when the show is running on a hot day like today (88 deg. F. outside temp), or even on an evening when itâ€™s only 70 outdoors. Itâ€™s the lights that are killing us! (As well as having 60 human bodies in there.) We tried shutting all the supply vents in the rest of the rooms to focus all the AC in the auditorium â€“ only a slight help. We tried cooling the aud down to 66 just before the show starts, but it still heats up very quickly when the lights come on and is close to unbearable by the end of the play. I am annoyed that the HVAC contractor didnâ€™t calculate the extra heat generated by the lights and people when he replaced the old 4-ton, which wasnâ€™t keeping us cool enough. He says he just figured â€œanother ton ought to do it for this square footage.â€ Heâ€™s not completely off base, I suppose: When the stage lights arenâ€™t in use, the 5-ton unit seems to cool the whole building ok. (We are guessing that 5 tons will also be plenty for heating in winter. Certainly the stagelights will be working in our favor then, and not against us.) So now he suggests selling me an extra 2Â½ -ton unit just for cooling, to augment the other. (I asked him why he didnâ€™t install a 6- or 7-ton unit in the first place and he said that gets into a lot of engineering and complicated city permits, which he says the 5-ton is small enough to avoid. Hmmph.) Possible fix: Another contractor said, why not try adding an exhaust vent fan or two in the auditorium ceiling. A quiet fan (under 2 sones) can move 100 cfm for example. The theory being that those lights are hanging just below the ceiling, why not vent that heated layer of air straight outside, before it circulates into the room and into the AC unit. Then perhaps the AC unit could work more effectively. Iâ€™d be inclined toward this low-tech, lower cost solution that seems to hit the problem right where it is generated, rather than buying another 2-ton unit just to augment the AC on these few worst days of summer. But, do we need to worry about where the air would come in, that the exhaust fans are removing from the building? We could let it draw through the auditorium doors, from backstage rooms, which arenâ€™t so warm. . . but then I suppose those rooms would need an outside inlet vent (from the back alley for example, where itâ€™s always shady). But even then, the incoming outdoor air might be as hot as 80 on some days. I suppose thatâ€™s still better than the 100 or 120 degree air (Iâ€™m guesstimating) weâ€™d be expelling. What do you all think about this situation? Thanks for any advice or suggestions. SPECS: Building ca. 1800 s.f. total. Rooms are: 650 sf auditorium (30x25 with 12 ft ceilings - just a large rectangular room, seats are not fixed) 400 sf lobby 2 dressing rooms, 150 sf ea. 2 bathrooms, 60 sf ea office, 75 sf.