IES-VE User Forum

Hi All,

In the NCM 2010, the fan power density of "VAV System" is based on Equation 9:

FPS = Max (FAR_max , SCR) x SFP

FAR: Peak fresh air supply rate set by NCM
SCR: Space conditioning supply rate

where SCR = Max ( PSH , PSC) / (p * Cp * deltaT)

PSH/PSC: Peak space heating/cooling load


My question is, how does IES calculate the PSH and PSC? If the PSH/PSC figures are based on the dynamic simulation, I would expect the "peak" figure taken would be in one morning hour, which is usually two to three times larger than the normal load as the ApCalc assumes an infinity plant size in the "heat up" hour.

Could IES clarify the issue?

Regards

Howard

Hello

This isnt an answer to your question about the peak values, but you do know that you can set the maximum heating and cooling values when creating the heating and cooling systems in ApacheHVAC right? This should help you get the right values i think.
When creating the HVAC system, you can set the heating source for each of the rooms, and then choose the maximum heating power.

From Kasper