The Halls Greenhouse autovent allows your greenhouse to reach a required temperature after which the window will start to open. Any rise in temperature will now cause the window to open wider.
Opening temperature range adjustable between 15C and 25C (59F and 77F). Will lift 7kg i.e. a window weighing up to 14kg (glass area not exceeding 0.75 sq. m in aluminium frame).
Can be used in conjunction with any Halls opening roof vent. When fitting to wooden greenhouses the window bracket and the gripper can be screwed directly onto the framework.
Lubricate all moving parts after fitting and each subsequent spring and autumn using a light oil. Use a grease or petroleum jelly for the piston rods. After long periods of low temperature and at least once a year take the weight of the window with one hand and move the adjusting screw.