Residential load calculation

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nizak

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Customer wants to add (4) 6KW outdoor patio heaters.

This is a new build. Can I delete the AC load from the load calculation and then add the 4 heating units at 40%?
The units are totally apart from the HVAC system. Each operated by a separate control.

thanks
 
Maybe.

Consider owners having a party, it is cool outside and you want the heaters on, but enough people are also in the house that the AC is also running. You want to leave them short on capacity in that situation? Might only be a few times a year but is the worst time for it to happen in customer's eyes.

I'd give them enough service conductor and overcurrent protection - let POCO take risks on transformer size - though they can usually get away with more in that aspect than you can with service equipment sizing
 
nizak said:
Customer wants to add (4) 6KW outdoor patio heaters.

This is a new build. Can I delete the AC load from the load calculation and then add the 4 heating units at 40%?
The units are totally apart from the HVAC system. Each operated by a separate control.

thanks
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No, the larger of 220.82(C) is for indoor HVAC appliances only.

Outdoor space heaters would be continuous loads not responding to thermostat settings, per 220.51 & 220.53

You should consider a separate 125A sub-panel for 24k VA calculated at 125% of load with no demand factor for continuous loads.
 
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