220.12 Lighting Load for Non-Dwelling Occupancies.
Code Change Summary: The unit loads permitted for load calculations have been removed and replaced.
NEC Table 220.12 has provided the general lighting loads by occupancy type for many code cycles and has only has a few minimal revisions since the 1970s. Those revisions included reducing the lighting loads in a few different occupancies based on the technology advancements over time, however a full examination of the data has never been available to support a revision to this table.
In the 2020 NEC®, the table has been completely reconstructed using data from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the International Energy Conservation Code (IECC) and also, dwellings and multi-family dwellings were moved out of the table altogether and now only referenced in new Section 220.14(J).
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC® edition of NFPA 70.
2017 Code Language:
220.12 Lighting Load for Specified Occupancies. A unit load of not less than that specified in Table 220.12 for occupancies specified shall constitute the minimum lighting load. The floor area for each floor shall be calculated from the outside dimensions of the building, dwelling unit, or other area involved. For dwelling units, the calculated floor area shall not include open porches, garages, or unused or unfinished spaces not adaptable for future use.
Informational Note: The unit values are based on minimum load conditions and 100 percent power factor and may not provide sufficient capacity for the installation contemplated.
Exception No. 1: Where the building is designed and constructed to comply with an energy code adopted by the local authority, the lighting load shall be permitted to be calculated at the values specified in the energy code where the following conditions are met:
(1) A power monitoring system is installed that will provide continuous information regarding the total general lighting load of the building.
(2) The power monitoring system will be set with alarm values to alert the building owner or manager if the lighting load exceeds the values set by the energy code.
(3) The demand factors specified in 220.42 are not applied to the general lighting load.
Exception No. 2: Where a building is designed and constructed to comply with an energy code adopted by the local authority and specifying an overall lighting density of less than 13.5 volt-amperes/13.5 m2 (1.2 volt-amperes/1.2 ft2), the unit lighting loads in Table 220.12 for office and bank areas within the building shall be permitted to be reduced by 11 volt-amperes/11 m2 (1 volt-amperes/1 ft2).
2020 Code Language:
220.12 Lighting Load for Non-Dwelling Occupancies.
N 220.12(A) General. A unit load of not less than that specified in Table 220.12 for non-dwelling occupancies and the floor area determined in 220.11 shall be used to calculate the minimum lighting load. Motors rated less than 1∕ 8 HP and connected to a lighting circuit shall be considered general lighting load.
Informational Note: The unit values of Table 220.12 are based on minimum load conditions and 100 percent power factor and may not provide sufficient capacity for the installation contemplated.
N 220.12(B) Energy Code. Where the building is designed and constructed to comply with an energy code adopted by the local authority, the lighting load shall be permitted to be calculated using the unit values specified in the energy code where the following conditions are met:
(1) A power monitoring system is installed that will provide continuous information regarding the total general lighting load of the building.
(2) The power monitoring system will be set with alarm values to alert the building owner or manager if the lighting load exceeds the values set by the energy code. Automatic means to take action to reduce the connected load shall be permitted.
(3) The demand factors specified in 220.42 are not applied to the general lighting load.
(4) The continuous load multiplier of 125 percent shall be applied.