Low bay Light fixtures should be used in areas where the bottom of the luminaire is less than 20 feet above the floor. Low bay fixtures are usually 22" - 28" in diameter in order to spread the light evenly. Low bay LED lighting fixtures have optical refractors that cover the lamp and reduce glare. Their widespread distribution improves vertical illumination and permits spacing as much as two or more times their mounting height. In addition, they can be mounted up to 25' when high vertical illuminance is required