Hi all,
I've got a question about calculating the pressure drop adjustments for a baseline building. I'm using LEED v4, ASHRAE 90.1 2010.
The proposed case has a DOAS ahu that supplies fresh air and 2 AHUs that recirculate air for cooling. The DOAS has MERV 7 and MERV 14 filter on the supply side and a MERV 12 filter on the return side. The recirculating AHUs have a MERV 12 filter. There are 3 similar systems like the schematics above. I'm supposed to calculate the pressure drop adjustments for the air flow passing through each section. Supply air is around 96000 L/s and fresh air is around 25000 L/s, which means around 24% goes through MERV 7+MERV 14 filters and 100% L/s goes through MERV 12 filters. MERV 7 filters are not specified so I can't take pressure drops for these.
The baseline has around 70790 L/s of supply air flow and 13580 L/s fresh air.
I've added it to the calculator as below but I'm not sure if this is correctly interpreted.
Second, I have 2 sound attenuator sections in my ducts on the supply side and 1 on the return side. How do I apply this to the calculator? I'm allowed to take credit of 38 pascal per sound attenuator section, however since they are not the same for the supply and return I'm not sure how to add this in the sheet. Also I can't change the 38 pascal in the sheet, do I multiply my airflow x2 in that case and how do I differentiate between supply and return?
Anyone who can guide on the approach here?
Thanks in advance!
Kind regards,
Boris Jonjic