Currently yes. There's a lot of heat capacity to the furnaces so a cold start requires a lot of heat to get to nominal. That's not to say one couldn't be design

Currently yes. There's a lot of heat capacity to the furnaces so a cold start requires a lot of heat to get to nominal. That's not to say one couldn't be designed in such a way that it can be set to idle without losing too much heat. It's probably much easier to do that if it's electric vs nat gas.