Hi LEED experts,
In the MEPC file, I see the Fan EFLH is determined by dividing the annual fan consumption by the total fan power (kW) in the tab "Performance Output". Based on the MEPC result, our energy model has a small difference between the Baseline and the Proposed Fan EFLH. However, the LEED reviewer commented that the Fan EFLH is determined by dividing the Annual fan consumption by the Total fan power in the "Air-side HVAC tab", not in the "Performance Output tab", which contradicts the MEPC and is quite confusing to me. Based on that idea, our model has a big difference between the baseline and the proposed EFLH and I have to provide a narrative for this. I think the MEPC file is correct because the fan power in the "Air-side HVAC tab" is the maximum capacity of the fan. The fans don't run full load all the time, so we can't use this maximum capacity to determine the fan EFLH. Which way is the correct to determine the fan EFLH?
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
September 5, 2024 - 8:09 am
I'm not sure there is a "correct" way to calculate the EFLH, just two different ways. If the EFLH calculated using the Air-Side HVAC tab fan power differ significantly from the EFLH calculated using the Performance Output fan demand, then the demand must be significantly lower than the fan power. So your narrative would be addressing this difference (i.e. the fans are not all running at their peak simultaneously as you described).