Walk in Freezer Auto Light Shut off

Hi Marcus & Jean, Thanks for your feedback. I got my interpetation from ASHRAE on a Request for Interpetatiopn form. I has hoping someone had dealt with this before and might have heard of other alternatives than occupancy sensor. The ASHRAE Interpetation states: Background: Our project is using door sensors for lighting controls for Walk in Freezers and Room Chillers. Do these qualify as an occupant sensor (Section 9.4.1.1b)? They would turn the light on when someone is inside, and turn off the light when it is closed. No one will be inside with a closed door. Interpretation: A door operated sensor for a freezer room counts as an occupant sensor for Section 9.4.1.1b of ASHRAE/IESNA Standard 90.1. Question: Is this interpretation correct? Answer: No Comments: A door sensor (switch) does not meet the intent or specific language/definition in the standard because it only senses whether the door is open or closed and not whether the room is occupied or vacant. Also this comment from ASHRAE rep: In a chiller space – such as a walk-in freezer – there needs to be an occupancy sensor or timer to control the lighting. The fact that it’s not regularly occupied highlights the reason for it. Say someone leaves the lights on when they walk out of the freezer. If it’s unoccupied for 176 hours until the next person walks in, the lights will have been on the entire time. Preventing that sort of un-needed illumination is why the requirement is written the way it’s written. So the example of “no one will be inside with a closed door” isn’t always true. If there’s mechanisms to allow people to exit, then there must be times when people are in a freezer with the door closed. We are looking into specialized occupancy sensors for freezers. There are some available on the market.