LEED Green Building Certification The purpose of the LEED Green Building Rating is to provide a national standard that aims to improve environmental, health and economic performance of buildings using established and/or advanced industry principles, practices, materials and standards. The purpose of this analysis is to assess the CAPA High School s mechanical system in each of the following categories: Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and LEED Innovation Credits. Water Efficiency This category places an emphasis on the utilization of water efficient landscaping, innovative wastewater technologies, and through water use reduction. The design of the mechanical system for the CAPA High School does not provide for any reductions in the use of water and therefore scores no points in this section. Energy and Atmosphere In this category, the mechanical system for the CAPA building meets two of the three prerequisites and scores two points out of a possible seventeen. Prerequisite 1 requires a fundamental building systems commissioning which is not performed on the CAPA building. Prerequisite 2, Minimum Energy Performance is met as a result of the building s ability to meet the requirements stated in ASHRAE Std. 90.1-1999, and prerequisite 3, CFC Reduction in HVAC&R Equipment, is met via the use of R-134a, an HCFC refrigerant, in all HVAC equipment. The CAPA building receives two points for the HVAC system s design which reduces energy costs by 20% as compared to requirements listed in ASHRAE Std. 90.1-1999 by utilizing economizers on all AHU s and VUV s, free-cooling in winter by converting condenser water into chilled water, use of VFD drives and high efficiency motors on the building s VAV system, minimizing outdoor air in auditorium and gym by using CO 2 monitors, and through the use of DDC temperature controls throughout the building. Other credits in this category are available for increased optimization of the energy performance, use of renewable energy, and additional commissioning, all of which are not provided for through the design of the building s mechanical system. Materials and Resources This category places an emphasis on the reuse and recycling of materials used throughout the project along with the use of materials found within the local region and the use of rapidly renewable materials. Most of this category is affected by the General Contractor s use of materials, and the building s mechanical system can only be credited for one point in this section, for the use of a minimum of 20% locally produced equipment. Building and Plant Energy Analysis Part A 1
Indoor Environmental Quality This category places an emphasis on taking measures to improve the indoor air quality (IAQ) of the building through the use of specific mechanical equipment to control CO 2 levels and thermal comfort. This section also gives points for the ability of users to control the mechanical system in there area and for providing daylight and views to the occupant as well as for using low-emitting materials and controlling the IAQ during construction. The CAPA building s mechanical system provides for compliance with the two prerequisites and scores 3 points in this section. Prerequisite 1, Minimum IAQ Performance, is provided for by the designer s use of the ventilation rate procedure to meet minimum requirements for ventilation stated in ASHRAE Std. 62-1999. Prerequisite 2, Environmental Tobacco Smoke (ETS) Control, is provided for by the zero exposure of tobacco smoke to non-smokers via the prohibition of smoking in the building. The CAPA building receives one point for its use of CO 2 sensors in return air ductwork in return air ductwork for all AHU s and through the use of a CO 2 monitoring system for the auditorium and gymnasium. Another point is received for an increase in ventilation effectiveness provided for by the ventilation system s ability to meet the air change effectiveness (E=0.9) described in ASHRAE Std. 129-1997. The third point is received for the controllability of the system which is provided through the building s design which allows for one operable window and one light control per 200 sq. ft. for occupied areas within 15 feet of perimeter walls. Innovation & Design Process Other points may be gained for the building through the use of non-chemical treatment of condenser water and a VFD ventilation exhaust fan used in the garage which is controlled by a carbon monoxide sensor. Additional points may also be received for the incorporation of a roof-top garden, which may provide additional help in dealing with run-off water during rainstorms and in reduction of heat islands. Building and Plant Energy Analysis Part A 2
ASHRAE Standard 90.1-1999 The purpose of this analysis is to determine if the CAPA High School s building envelope is within compliance with ASHRAE Std. 90.1-1999. For this analysis section 5 of the standard was used to determine compliance. The first step in the procedure is to determine the CDD50 and HDD65 values for the city of Pittsburgh, PA which are 2836 and 5968 days, respectively. For these values it is necessary to use Table B-17 in Appendix B to determine the minimum and maximum values for compliance. The CAPA high school is classified as a non-residential building and has a roof with insulation entirely above deck, mass walls above grade, and steel joist floors. The exterior vertical fenestration comprises up 28% of the total exterior wall area and therefore falls into the 20.1-30.0% profile. When determining the U- and R-values for the building, I took the construction information off of the architectural drawings and inputted that material into Carrier s Hourly Analysis Program v.4.10, to determine the U- and R-values for the building materials. The CAPA High School was found to be compliant with Std. 90.1-1999 and supporting information can be found on the table below. Building and Plant Energy Analysis Part A 3
Lighting Compliance For the lighting compliance section, I chose to look at 3 typical spaces within the building and compared the power density of the spaces to the maximum power allowance values in ASHRAE Std. 90.1-1999. The three spaces I chose were a classroom, a corridor, and an office. All spaces were found to be compliant within the code limits and the calculations may be found in the following table Equipment Spacing I have gone through the drawings for the mechanical system and have verified that all of the mechanical equipment has adequate spacing around it to allow for servicing of the equipment. In order for the equipment to be serviced a distance equal to the width of the piece of equipment is required for each component in the mechanical room. The 2120 square foot mechanical room located in the basement, room B10, allows for enough space to house two water chillers, two hot water boilers and ten water pumps. The second floor mechanical room, 215, is 190 square feet and houses one air handling unit. The mechanical rooms on the fourth floor, 413 and 430, are 233 and 278 square feet, respectively. Room 412 houses one air handling unit and room 430 houses a heat recovery unit. The seventh floor penthouse is 4480 square feet and provides room for eight air-handling-units. Mechanical System Cost Breakdown The mechanical system for the CAPA High School costs approximately $4.2 million and makes up 12 percent of the total cost of the building. The price per square foot of the 175,140 square foot facility is approximately $24. HVAC Systems Cost Total Addition & Renovation $ 4,204,916 Area Addition & Renovation 175,140 sq ft Cost/sq ft $ 24.01 Building and Plant Energy Analysis Part A 4
Lost Rentable Space The total amount of lost rentable space comprised of the mechanical rooms and duct chases, is equal to less than 3% of the total building area. Plenum spaces are also kept to a minimum throughout the building which has caused many construction issues concerning the placement of needed equipment in these spaces. Breakdown of lost rentable space due to mechanical equipment Floor Description Lost Area - sf Basement B01 - Environmental Mechanical 272 Basement B10 - Mechanical Equipment Room 2120 Basement B12 - Existing Emergency Generator Room 371 Basement Elevator Shaft - Exhaust Fan 100 1 st Back Alley Chase 58 1 st East Stair Chase 34 1 st Pipe Chase 3.5 1 st Elevator Shaft - Exhaust Fan 54 2 nd 215 - Mechanical Room 190 2 nd Back Alley Chase 68 2 nd East Stair Chase 34 2 nd Pipe Chase 3.5 2 nd Elevator Shaft - Exhaust Fan 54 3 rd Back Alley Chase 70 3 rd East Stair Chase 34 3 rd Pipe Chase 3.5 4 th Back Alley Chase 196 4 th East Stair Chase 34 4 th Pipe Chase 3.5 4 th 413 - Mechanical Room 233 4 th 430 - Mechanical Room 278 4 th Bathroom Chase 11 5 th Back Alley Chase 230 5 th East Stair Chase 34 5 th Pipe Chase 3.5 5 th Bathroom Chase 94 6 th Back Alley Chase 230 6 th East Stair Chase 35 6 th Pipe Chase 3.5 6 th Bathroom Chase 94 Total 4949 Total Building Area 175,140 Percentage of Area 2.8 % Building and Plant Energy Analysis Part A 5