You're missing heat dissipated by the ballasts and the cooling requirements for the room volume as well.3Kw = 10,242 Btu/hr worth of heat
The sunlight supply website has a btu calculator that accounts for pretty much everything. It's totally plug and play.You're missing heat dissipated by the ballasts and the cooling requirements for the room volume as well.
A ton of cooling for each lamp?? That’s insane lol. I ran 4 phantom de’s last run and cooled them with a single 8” intake from outside. It’s winter so temps would get down to 35-40 at night and my fan would actually turn off on thermostat.24k BTUs would just cover cooling needs if ceiling height is 8 feet. I’d go with 36k personally.