when do i consider the heating as continuous

[stealinhomeNY]

When calculating a commercial service demand load, when do I know whether to consider, office building example 8.9 in 2023 prep exam book, its heating as a continuous load. The ac was 15 kva, the heating was 14 kva. So if taken at 125% it would be considered the larger of the two. Please clarify, thanks

 

[ggunn]

When calculating a commercial service demand load, when do I know whether to consider, office building example 8.9 in 2023 prep exam book, its heating as a continuous load. The ac was 15 kva, the heating was 14 kva. So if taken at 125% it would be considered the larger of the two. Please clarify, thanks

A continuous load is one that is on line for three hours or more at a time. Heating and HVAC are both continuous loads, I believe.

 

[augie47]

Heating units are considered continuous loads when sizing branch circuits but AFIK they are sized at actual load when calculating loads,.

 

[infinity]

Heating units are considered continuous loads when sizing branch circuits but AFIK they are sized at actual load when calculating loads,.

That's what is says in 220.51.

220.51 Fixed Electric Space Heating.
Fixed electric space-heating loads shall be calculated at 100 percent of the total connected load. However, in no case shall a feeder or service load current rating be less than the rating of the largest branch circuit supplied. Exception: Where reduced loading of the conductors results from units operating on duty-cycle, intermittently, or from all units not operating at the same time, the authority having jurisdiction may grant
permission for feeder and service conductors to have an ampacity less than 100 percent, provided the conductors have an ampacity for the load so determined.