Our building is a 56 floor, 1 million gross square foot (GSF) high rise office building in a major metropolitan city. The building has four space types: 1) retail tenant 2) lobby 3) commercial office, and 4) server room. The retail tenants are located on the ground floor and are served by dedicated HVAC systems. The commercial office spaces are located on floors 2 through 56 and are served by dedicated floor-by-floor air handlers with VAV boxes and electric reheat. The server rooms are located on floors 2 through 56 and are served by dedicated cooling systems. The server rooms combined comprise less than 1% of the total GSF of the site. Due to the amount of tenant improvement projects that have been completed since the building was built in the mid 1980s, a complete set of current mechanical and architectural drawings for the building are not available. However, the original mechanical infrastructure has remained unchanged. Given the large size of this building, the large number of tenants, and lack of complete documentation, we are proposing a sampling strategy to document that the building complies with EQ Prerequisite 1. Specific details are summarized below. Note that for the purposes of this CIR, "calculation" implies a calculation confirming ASHRAE 62.1-2004 ventilation rates was completed. Occupancy levels for each space will be based on ASHRAE 62.1 2004 guidelines. Calculation Approach: Retail: One calculation will be completed for each retail tenant space. Lobby: One calculation will be completed for the lobby area. Commercial office: Confirmation that each office space is served by a typical HVAC system will be completed through site surveys, customer interviews and review of available drawings. Once confirmed, calculations will be completed on 10% of the air handlers and/or floors to show that these floors meet EQ Prerequisite 1. If unique spaces in terms of space use or HVAC system type are discovered, separate calculations will be completed for those unique spaces. Server rooms: Excluded from the scope of this credit because they are not regularly occupied spaces, and because they comprise less than 1% of the total site GSF. Submissions: The actual minimum ventilation rate for the each AHU will be measured and compared with the outdoor ventilation rates calculated above. In addition, documents will be submitted (i) ensuring that the building exhaust systems are working as designed, and (ii) shall include the results of a quarterly inspection of building OA & exhaust systems to confirm they are working as designed. Will this proposed strategy meet the requirements and intent of the EQ Prerequisite 1? If not, please clarify how this proposal should be revised.
The proposed approach would meet the requirements of this credit as long as actual delivered outdoor air ventilation rates are measured and reported for all AHUs serving the building. ASHRAE 62.1-2004 requires minimum zone outdoor airflow based on space use, square footage, and occupancy within each ventilation zone. For multiple-zone systems, the minimum outdoor air intake flow at the air handling unit (AHU) must be determined based on the system type and the minimum zone outdoor airflow required by each zone served by the AHU. Actual OA delivered must be reported for all AHUs serving the building. To demonstrate compliance with ASHRAE, OA delivery from each AHU serving occupied zones must be tested and reported. Where this is not feasible due to the physical constraints of the existing ventilation system, you must document that the system supplies at least 10 CFM/person for each of the applicable space types under each AHU and clearly illustrate the physical constraints. For more information, please see the LEED-EB V2.0 Reference Guide Second Edition October 2006 language detailing the calculation and documentation requirements for this prerequisite. ASHRAE 62.1-2004 requires a delivered OA ventilation rate that equals or exceeds the minimum outdoor airflow rate in the breathing zone (Vbz), found as follow: Minimum Vbz = (Rp