Hello, I'm trying to get some cliarity regarding residential zone exhaust (from toilet exhaust and kitchen exhaust). 

Looking at the multifamily guidelines "Supply and exhaust fans that are installed for a purpose other than providing whole-unit ventilation, such as bathroom and kitchen local exhaust fans, laundry make-up air fans, trash room exhaust, etc. shall be modeled as process loads." - so my interpretation is that they should be applied as process loads. 

Additionally, looking through past forum discussions (more in v2009), exhaust fans that are not interlocked with the HVAC are considered process (https://leeduser.buildinggreen.com/forum/exhaust-fan-not-interlocked-hvac-process-energy-or-not). 

However, based on comment from a LEED reviewer  "Note that exhaust fan power is already included in the Baseline Case, because the sum of the design supply, return, exhaust, and relief fans for each Baseline HVAC system to be equal to the power calculated in G3.1.2.9. Update the model so that all Proposed HVAC system parameters (e.g. fan volumes, fan powers, efficiencies, heating/cooling capacities, etc.) are consistent with the design documents, update the Minimum Energy Performance Calculator to reflect all changes made. Additionally, provide SV-A report from e-Quest." -- so in the baseline it sounds like it cannot be treated as a process load and must therefore be modeled at the space? And the proposed as well to be consistent (and to reflect in the SV-A). 

In this particular case the exhaust fans are not tied into a larger system (proposed is PTHP) and are being directly exhausted at the roof. 

In the past we have modeled as identical process loads running 2 hr/ day based on multifamily guidance and this has been accepted (or perhaps just not reviwed).  Looking for clarity if directly at the zone or as a process load is more appropriate for this case but also in general.