How do we calculate the Ds value for the condition where "The cooling load is low due to minimal envelope and internal loads but the number of occupants are at peak?" We have the following comment from USGBC and do not know how to go about it. Some PLEASE HELP "In the cooling mode, the worst-case scenario occurs when the zone supply flow rates are low as the cooling load decreases with less envelope and internal loads, but the zone occupant number could be at the peak. The Ds value of 100% is associated with the peak cooling design conditions. The worst case conditions for ventilation do not occur at peak cooling design conditions, but rather occur when the critical zones are fully occupied, but have minimal envelope loads and minimal other internal loads (such as lighting or plug loads). Although the project is located in climate zone 1, the TMY climate data indicates that the zones are not expected under the peak cooling mode year round. The Ds value must represent the ratio of the flow at the worst-case condition analyzed (typically the minimum supply for each zone and the minimum supply airflow at the system level) for the flow at design conditions. Provide a narrative explaining how the worst-case condition was determined considering the total design airflow rate at the condition analyzed (Ds)."
LEEDuser Basic Member
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