Residential projects without directly ducted makeup air typically get makeup air either from operable windows alone, from operable windows plus pressurized corridors, or from either or both of those sources, plus negative pressure created by bathroom fans and kitchen exhaust hoods (which may or may not be always on). For LEED NC 2.1 projects, it was asked whether CO2 monitors must be provided for low density residences. In the CIR ruling from 9/20/2004, it was confirmed that CO2 monitors for these residential spaces are not necessary to meet the intent of the credit. For LEED NC 2.2 projects, does this ruling from 9/20/2004 apply? Do residential units without ducted makeup air now require CO2 monitoring? If the ruling varies depending on the strategy by which the units receive makeup air (operable windows, pressurized corridors, bathroom and kitchen fans alone or in combination), can you indicate which scenarios require CO2 monitoring and which do not?
The applicant is requesting clarification on the applicability of a LEED NC 2.1 CIR ruling for LEED-NC 2.2. Under LEED-NC v2.2, EQc1 has been modified to include two methods of compliance: 1. For densely occupied areas (25 persons/ 1000 SF) use CO2 monitoring 2. For systems serving all other spaces employ outdoor air delivery monitoring Based on the information provided in this inquiry, the first option described above does not apply to individual residential units. Therefore, the second option should be followed. If the outside air (OA) supply is through a pressurized corridor, the implementation of this credit is straight forward. If OA is introduced directly to a conditioning unit (for example- a heat pump or a fan-coil unit) it may be possible to monitor OA delivery to the unit individually. For all other modes of OA supply, this credit may not be applicable. If the residential project has any densely occupied spaces such as meeting rooms, CO2 monitoring should be provided for those specific spaces.