RNG, no flaps, but I have considered temp. I left the eave portions of walls open and a narrow gap at base of panels to allow circulation. Also on the list is the possibility of installing a fan or 2 for additional air movement. I have 2 Pv panels to setup independent power from house for the hydroponic pumps, lights, and fans. Haven’t decided whether to stay DC or add small inverter, leaning DC.