Relation of System Air Heat Transfer Rate and Sensible Cooling Rate of Coil
Hello, I am learning to understand how the heat gain calculation happened in Energy Plus, and I am reading in the ASHRAE Handbook of Fundamental that the instantaneous space sensible load should be same with the heat removal rate of conditioning equipment.
I am looking at the zone air heat balance to look at each components contribution to the zone sensible load.
Based on the observation in my result, the Zone Air Heat Balance System Air Transfer Rate number match with the sum of
Zone Air Heat Balance Internal Convective Heat Gain RateZone Air Heat Balance Surface Convection RateZone Air Heat Balance Interzone Air Transfer RateZone Air Heat Balance Outdoor Air Transfer Rate
minus the Zone Air Heat Balance Air Energy Storage Rate.
Based on the sentences, what I understand is that the zone air heat balance system air transfer rate should be matched with the zone cooling coil sensible cooling rate, is that correct?
However, when I check the number, there is always a constant difference between those number in each day. Am I using the right parameter to compare? Or there is any parameter that I need to check in order to have the same number with system air transfer rate?
Thank you
(EDIT)
For this model, I tried to define all the equipment that would be used in the building, and not using the autosize number for the equipment characteristics.
I take it the cooling coil rate is greater than the
Zone Air Heat Balance System Air Transfer Rate? Can you provide an approximate percent difference?My first instinct was that it's not capturing solar gains (from the list you included above); however, I think that is either wrapped in with internal gains or winds up being a contributor to surface convection rate (I'm getting my software mixed up).
I'd also confirm that 'Outdoor Air Transfer Rate' includes both ventilation and infiltration air.
I edit my question with the calculation data of the heat air balance of my model. The cooling coil rate is lower compared to
zone air heat balance system air transfer rateas you could see in the image. I have more than one thermal zone in my model, and for each thermal zone, the percentage is different. I am trying to understand where does the difference come from.