IdealAir Heating and Cooling Energy Use at the Same Time?

edit

Hi all,

I have a question I'm trying to understand about IdealAir loads results and wondering if anyone can clarify for me or point me towards the right reference document? I am looking at the output results for a singe zone model (NYC climate, commercial occupancy) and currently I'm just modeling IdealAir loads. When I look closely at the results "IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Supply Air Total Heating Energy (Hourly)" or the cooling, I find some periods where its showing both heating energy AND cooling energy use at the same time?

For instance, during a shoulder season week:

I'm just trying to understand what this 'means' in the case of a single zone model? I would have though it would be either heating OR cooling during any 1-hour period? These overlaps seem to occur reasonably often in my results here. Appreciate any clarification on this.

Thanks very much! -Ed