The project is located in Downtown Los Angeles and is registered under LEED NC Version 2.2. It includes two high-rise towers with condominiums, affordable housing units, and apartments. It will pursue a LEED Silver rating. The LEED team is reviewing the requirements for EQ Prerequisite 1, Minimum IAQ Performance and compliance with ASHRAE 62.1-2004, including Appendix E. The team needs to assure that its design of the kitchen exhaust systems and venting of stove hoods complies with the ASHRAE standard, and we have reviewed the LEED Version 2.2 Credit Interpretation Rulings regarding this requirement: A recent USGBC CIR submitted on 8/30/07 regarding a 7-story residential unit im Massachusetts asked the following question: "Under ASHRAE 62.1, 2004 are apartment kitchens required to be exhausted to the outdoors? If so, is there any way the bathroom exhausts could satisfy this requirement?" On 9/24/07, the USGBC issued a ruling stating: "The third question is asking whether under ASHRAE 62.1 2004, kitchens are required to be exhausted to the outdoors. If the kitchens qualify as naturally ventilated spaces, and there are no special requirements for combustion air or removal of combustion products, then there is no exhaust requirement. If the kitchens do not qualify as naturally ventilated spaces, then they will have to meet the exhaust requirements laid out in Appendix E: 100 cfm intermittent or 25 cfm continuous exhaust." As noted above, the project includes two high rise residential towers, one being 47 stories and the other 28 stories in height. Due to the height of buildings and acoustical requirements of the City of Los Angeles pertaining to residences, the units are designed as mechanically ventilated spaces. Gas cook tops are provided in all residences, with recirculating exhaust hoods above each. To comply with ASHRAE 62.1, 2004 we propose extending a duct from the general exhaust riser system and terminating them with a grille in the ceiling or wall of each kitchen. We had analyzed air changes in the kitchen utilizing three different methods and as shown on the table below we have demonstrated that we meet ASHRAE ventilation rates. Is this an acceptable means of meeting the intent of the standard? Project T1 and T2 Residence space ventilation analysis ASRAE 62.1 - 2004 Bedroom is a Class 1 space Per Table 5-2 pg 9 Kitchen Air is Class 2 Per Table 5-2 pg 9 This air can be recirculated Per Section 5.17.3.2 But not to a Class 1 space Minimum Ventilation Rate Table 6-1 pg 12 CFM per person 5 CFM per square ft 0.06 cfm per sf Occupancy Density 10 per 1000 sf CFM per person 11 Minimum exhaust rate Table 6-4 pg 16 Kitchenettes 0.30 cfm per sf Appendix E Pg 38 Kitchen OSA = 100 cfm intermittant or 25 cfm continuous Tower 1 Tower 2 200 SF per person by Total SF: 767 683 People: 3.835 (say 4) 3.415 (say 4) 4 people x 5 = 20 cfm 20 cfm 767 sf x 0.06 = 46.02 cfm 40.98 cfm OSA cfm = 47 cfm 41 cfm by Occupancy rate 7.67 people 6.83 people at 11 cfm per person 84.37 cfm 75.13 cfm Kitchenette exh rate: Kitchen SF 67 70 at 0.30 cfm / sf 20.1 21 Design exhaust for: 100 cfm 100 cfm