I don't have the duct venting into the attic yet, just blowning the air out into room that both rooms are in, and the temps in the flower room have been in high 60's low 70's, and in day with the lights off and exhaust fan off, its low 60's so I will have to keep a eye on the temps because winter is coming and its and getting colder now.I might need a heater for the veg room, going to wait until homedepot starts stocking heaters seasonal bs, I'll see how the temps go