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I don't think the IAQ calculator is significantly deficient.

Exhaust only spaces such as restroom and locker rooms are not found in the IAQ calculator because they are not listed in ASHRAE 62.1 TABLE 6-1 MINIMUM VENTILATION RATES IN BREATHING ZONE. They are unoccupied spaces. EQ Prerequisite Minimum indoor air Quality Performance credit and the IAQ calculator are for occupied spaces. OA flow rates in unoccupied spaces do not need to be added to the IAQ calculator and the Minimum Energy Performance Calculator (MEPC). If you want to add the OA flow rates in unoccupied spaces to the MEPC dut to the energy consumption of precooling/preheating the OA, please explain the difference in the total OA flow rate between the IAQ calculator and MEPC to GBCI.

I don't see the numbers 0.17CFM/SF for Science labs and 0.33CFM/SF for Kitchens in the IAQ calculator. The OA flow rates in the IAQ calculator are 0.43CFM/SF for Science labs and 0.27CFM/SF for Kitchens with default zone population. Rp and Ra in the IAQ calculator are consistent with those in ASHRAE 62.1 TABLE 6-1.

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The minimum OA flow rates in TABLE 6-1 are for occupants. If you have local exhausts such as Fume hoods in Science labs to remove pollutants and Range hoods in Kitchens to remove odors, those local exhausts (and the makeup air supply fans, if any) are regarded process loads. In the Baseline case, the process loads should be modelled identically to the Proposed case. The makeup air (outdoor air or transfer air from the other zone) does not need to be added in the IAQ calculator.

1.00CFM/SF for Science labs and 0.70CFM/SF for Kitchens are the values in ASHRAE 62.1 TABLE 6-4 Minimum Exhaust Rates. TABLE 6-4 is irrelevant to EQ Prerequisite Minimum Indoor Air Quality Performance and EA Prerequisite Minimum Energy Performance.

I don't think the IAQ calculator is significantly deficient.

Exhaust only spaces such as restroom and locker rooms are not found in the IAQ calculator because they are not listed in ASHRAE 62.1 TABLE 6-1 MINIMUM VENTILATION RATES IN BREATHING ZONE. They are unoccupied spaces. EQ Prerequisite Minimum indoor air Quality Performance ~~credit~~ and the IAQ calculator are for occupied spaces. OA flow rates in unoccupied spaces do not need to be added to the IAQ calculator and the Minimum Energy Performance Calculator (MEPC). If you want to add the OA flow rates in unoccupied spaces to the MEPC dut to the energy consumption of precooling/preheating the OA, please explain the difference in the total OA flow rate between the IAQ calculator and MEPC to GBCI.

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Supplement to answer your comments

In LEED, Nonregularly Occpied Space is a more accurate description than Unoccupied Space for restrooms and lockers. I apologise. The definition 'an area that people pass through or an area used for focused activities an average of less than one hour per person per day' and the examples are in the LEED Reference Guide for BD+C: LEED V4. However, this classification misleads addressing your original questions, so please ignore it. Whether the Occupancy Category is listed in ASHRAE 62.1 TABLE 6-1 MINIMUM VENTILATION RATES IN BREATHING ZONE or not - that's all. If the Locker rooms in your project are used mainly for meetings for hours rather than just for changing clothes, you may need to select a different Occupancy Category such as Conference / meeting in the IAQ calculator in contrast to the space name shown on the floor plan.

Please do not confuse Ventilation with Exhaust. Ventilation requires outdoor air, but Exhaust does not necessarily require outdoor air (e.g. transfer air is allowed). ASHRAE 90.1-2010 G3.1.2.6 is a requiremnt for Ventilation. It describes Minimum ventilation system outdoor air intake flow. It does not describes minimum exhaust flow. EQ Prerequisite Minimum indoor air Quality Performance is the prerequisite for Ventilation. The IAQ calculator is for Ventilation, not for Exhaust.

To be accurate, how to model kithcens and locker rooms depend on the Proposed design. In my past LEED projectgs, when they were unconditioned, the exhaust fans and the makeup air supply fans were modelled as process fans i.e. they were modelled identically in the Proposed case and the Baseline case. When a kitchen was conditioned but the makeup air was supplied very close to the range hood and did not affect the air conditioning of the kitchen space, the exhaust fan and the makeup air supply fan for the range hood were also modelled identically. When a kitchen space was uncoditioned but the makeup outdoor air was precooled, I regarded the precooling as a process load, and I modelled the precooling coil upstream of the makeup outdoor air supply fan in the Basline case identical to the Proposed case.

I don't have an experience, but if a kitchen is conditioned and the makeup air for the range hood is supplied and well-mixed in the kitchen space, it would affect the air conditioning of the kitchen space and the HVAC system in the Baseline case should follow ASHRAE 90.1-2010 G3.1.1 (d). The maximum exhaust flow rate allowed for the range hood in the Baseline case is limited by the ASHRAE90.1-2010 Section 6.5.7.1.3 (Not limited by ASHRAE 62.1 TABLE 6-4).

For locker rooms, all the locker rooms in my past LEED projects were conditioned. The HVAC system in the Baseline case (e.g. System 7—VAV with Reheat) was simply determined by the Building Type. A VAV system conditioned not only the locker room but also many other zones on the same floor. I modelled the OA flow rates in the locker rooms in the Baseline case identical to the Proposed case. I did not add the OA flow rates of the locker rooms to the IAQ calculator. The total OA flow rate in the IAQ calculator was slightly different from the total OA flow rate in the MEPC, but the slight difference was accepted. If the difference is not slight (e.g. more than 5%), the LEED review team may comment on that, but we can explain the reason i.e. the OA flow rates of the locker rooms are not included in the IAQ calculator.