220.14(J) Dwelling Units.
Code Change Summary: Revised code section on dwelling unit load calculations.
In the 2020 NEC®, Section 220.14(J) was expanded with the necessary requirements previously found in Table 220.12 since the table was changed and now only pertains to non-dwelling unit type occupancies. Also, the previous language on guest rooms, hotels and motels were removed relocated to 220.14(M).
When calculating the minimum unit load, the revised language in 220.14(J) points the reader to new Section 220.11 which states:
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.
A change regarding small motors was also added to this section. Now, motors rated less than 1/8 HP and connected to a lighting circuit are included in the general lighting load. Some ceiling fans and exhaust fans are examples of motors rated less than 1/8 HP.
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:
220.14(J) Dwelling Occupancies. In one-family, two-family, and multifamily dwellings and in guest rooms or guest suites of hotels and motels, the outlets specified in (J)(1), (J)(2), and (J)(3) are included in the general lighting load calculations of 220.12. No additional load calculations shall be required for such outlets.
(1) All general-use receptacle outlets of 20-ampere rating or less, including receptacles connected to the circuits in 210.11(C)(3)
(2) The receptacle outlets specified in 210.52(E) and (G)
(3) The lighting outlets specified in 210.70(A) and (B).
2020 Code Language:
220.14(J) Dwelling Units. In one-family, two-family, and multifamily dwellings, the minimum unit load shall be not less than 33 volt-amperes/m2 (3 volt-amperes/ft2). The lighting and receptacle outlets specified in 220.14(J)(1), (J)(2), and (J)(3) are included in the minimum unit load. No additional load calculations shall be required for such outlets. The minimum lighting load shall be determined using the minimum unit load and the floor area as determined in 220.11 for dwelling occupancies. Motors rated less than 1∕8 hp and connected to a lighting circuit shall be considered part of the minimum lighting load.
(1) All general-use receptacle outlets of 20-ampere rating or less, including receptacles connected to the circuits in 210.11(C)(3) and 210.11(C)(4)
(2) The receptacle outlets specified in 210.52(E) and (G)
(3) The lighting outlets specified in 210.70.