Some interpretation requests have been sent to ASHRAE SSPC 15 regarding paragraph 7.5.1.2 on VRF or Split DX equipment (piping, fan coil units, VRF distribution boxes) located above the ceilings of public corridors and lobbies. As a result, ASHRAE recently published a clarification in the form of a formal interpretation (IC-15-2002-13) found here.
The interpretation agrees that refrigerant components such as VRF distribution boxes located ABOVE a false ceiling are not considered to be "IN" the corridor or lobby, and are thus allowed. As a result, components such as refrigerant piping, fan coil units, and distribution boxes can continue to be installed above corridor and lobby pathways. There was confusion surrounding the use of the work "in" [corridors or lobbies], however, "in" is not the same as "above".
The history of this paragraph has always dealt with refrigerated equipment entirely located on the floor of a lobby or corridor, such as vending / ice machines or water-coolers, or equipment that could impede someone's avenue to exit a building. These systems must be "Unit Systems," defined as self-contained systems where all the components of the system were factory assembled and charged at the factory. With some of these vending / ice machines and water-coolers now turning to ultra-low GWP refrigerants such as R-290 (Propane), ASHRAE SSPC 15 felt it necessary to limit the amount of any Class A2, 2, or 3 refrigerants in those types of systems.
However, A1 or A2L VRF or split systems can continue to be installed above false ceilings of corridors and lobbies without the specific refrigerant charge limitations of these unit systems, so long as they comply with the rest of the standard.