We have recently came across a question on whether we have to sprinkler a space that contains electric HVAC equipment for residential rooms. We are dealing with a NFPA 13 system that contains residential living units. We are utilizing residential heads in this area and only calculating the most demanding four sprinklers. In order for us to be the most cost effective on the job we decided to omit sprinklers from the HVAC unit space and here is our justification why; Per NFPA 13 18.104.22.168.2 we are interpreting this space as being a non-combustible concealed space and even though the space has an access door it will only be able to be opened by the facilities and not the tenant holder themselves (limited Access). The small space is surrounded with dry wall and has no possibility of storage due to the locked access and size of area. The equipment in question is a coil unit with only a circulation pump. No gas. The coil unit would take up the entire space, wall to wall and floor to ceiling. If the head ever developed a leak or needed replacement the owner would have to remove the entire unit and all supporting piping and duct to access. Would you agree that we interpreted NFPA 13 correctly and that this space does not need sprinklers? The AHJ has indicated if you agree with our interpretation he would follow suit.