Including load for Electric Duct Heaters being used for Reheat.

[Eddie702]

Not an NEC Issue. It's a design issue

If the heat pump is locked out at lo temp and they go to electric heat then use the larger of these two loads heat pump or electric.

If the electric heat is used for reheat (they do this for humidity control sometimes) then you have to carry the whole load.

If they are reheating already cooled air their not supposed to it's against the energy code unless it's a temperature and or humidity controlled room like a computer room or lab

 

[Sparky2791]

So does system design lockout the heat pump when calling for this aux heat or not?

NEC never mentions it but the compressor won't be drawing anywhere near rated load in that situation if it is running.

It does not lock it out.

 

[Sparky2791]

Not an NEC Issue. It's a design issue

If the heat pump is locked out at lo temp and they go to electric heat then use the larger of these two loads heat pump or electric.

If the electric heat is used for reheat (they do this for humidity control sometimes) then you have to carry the whole load.

If they are reheating already cooled air their not supposed to it's against the energy code unless it's a temperature and or humidity controlled room like a computer room or lab

Not for re-heat. That was my mistake. Simply aux heat for those times when compressors cannot keep up.