Natural ventilation greenhouses are easier and more affordable to control with Bartlett Instrument’s new RWL11X2 environmental controller. This model features DIF, DAY and NITE stages for better crop management. The controller features two heats and two time-proportional outputs for precise temperature control. The proportional outputs open and close in five steps and have a manual override feature. The RWL11X2 can be used to control a single zone or two separate zones. Other outputs include a timer/mister and alarm.