Hi Hap Users,

I am filing a project for LEED Certification. It is a Residential Building where the Baseline Model uses PTAC with Mechanical Ventilation and the Proposed Design uses DX with Natural Ventilation (Trickle Vents).

This is how I am modeling the two buildings and I would like to see what the experts out there think.

Baseline Model:

- Space Inputs:

o OA Ventilation: (Dwelling Units - ASHRAE 62.1)

o Infiltration: (Only when fan is off - Using Manual J Table 5B values for the ACH)

- System Input:

o Fan Control: (Fan On)

o Zone Sizing Ventilation (Computer Generated - auto calculated from the space inputs as ASHRAE 62.1)

- Design Load Summary Results:

o Since the infiltration happens when the fan is OFF, but it is set to be ON 24/7 then my infiltration value is ZERO.

o Ventilation is calculated to be 6000CFM for the whole residential portion of the building.

Proposed Model:

- Space Inputs:

o OA Ventilation: (Dwelling Units - ASHRAE 62.1), this is technically useless and these values will not be used anywhere.

o Infiltration: (All Hours - Pluged in the ASHRAE 62.1 manually calculated values)

- System Input:

o Fan Control: (Fan Cycled)

o Zone Sizing Ventilation (User Defined - Pluged in Zero value because no mechanical ventilation exist at the terminal units)

- Design Load Summary Results:

o Since the infiltration happens All Hours, I get an output cooling load for the infiltration.

o Ventilation is calculated to be ZERO because it was pluged in as Zero under the Zone Sizing Ventilation.

I am satisfied with this way of designing the two buildings but I need to show the LEED Reviewer that Mechanical Ventilation in the Baseline Building is equal to the Natural Ventilation (infiltration in this case). I couldn't find a way to generate a hap report that shows the infiltration air flow in CFM! Any help with that would be appreciated.

Best Regards,
Khaled