We have a CI project with multiple zone units and VAV system. We are using template VRP compliance calculator. For filling it, there are no instructions on the template or in ASHRAE on what "Vdzd" means. 62MZ Calc, states that Vdzd is the "Design total supply to zone (primary plus local recirculated)". The Refence Guide states that "for VAV systems, Vpz is the minimum expected primary airflow for design purposes", and we understand that these statements are conflicting. Wich volume is correct to consider? It seems that the VRP calculator already takes in consideration the Vpz minimum airflow. Is this correct?
In the VRP calculator we are using the total supply air in the zone as described for Vdzd, and considering Ds as 100%. Is that correct?
Thank you,
Juliana
Roger Chang
Principal, Energy and Engineering LeaderDLR Group | Westlake Reed Leskosky
LEEDuser Expert
398 thumbs up
December 19, 2011 - 9:48 am
Ds should be adjusted to consider the heating design flow rate, which will usually be significantly less than the cooling design flow rate. Vdzd is the total supply air.