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HomeMy WebLinkAbout2022-3-2 Appendix 2 EngineeringCity of Iowa City Senior Center Assessmentand Master Plan Appendix 2: Engineering Report March 2, 2022 Building Assessment for Iowa City Senior Center Iowa City, Iowa IMEG #20001495.00 A. Introduction 1. IMEG Corporation was engaged to review the existing 24,348 square-foot Senior Center facility in Iowa City, Iowa. This assessment is comprised of an existing infrastructure review, suggestions for improvements or requirements for the planned renovations, energy analysis to reduce building carbon emissions by 45%, and a feasibility study for achieving a NetZero building. B. Fire Protection 1. The building appears to be fully sprinkled. It appears the ground floor of the building was sprinkled in 1979. There was a project in approximately 1999 that updated the fire protection service and provided sprinklers on First Floor, Second Floor, and the Mezzanine Floor plan. The City mentioned a new sprinkler service was provided within the last five years. C. Plumbing 1. There was a major renovation of the building in approximately 1979. It appears all the domestic water piping, sanitary, and vent above grade on ground floor was all redone at that time. The incoming water service outside the building and underfloor sanitary all appear to be original to the building. It appears new roof drains were installed in 1979 and the drawings noted a secondary drain, but we did not see any secondary roof drains present during the walkthrough on the roof. The roof drains in 1979 were connected to existing storm piping and appear to have been connected to the primary storm system. 2. Most of the plumbing fixtures were replaced within the last five to ten years for the restroom groups. Electrical water coolers have all been replaced within the last two years. The kitchen fixtures appear to be all the same vintage as the kitchen equipment. 3. The piping to the fixtures appears to have been replaced when the fixtures were replaced, but it does not appear the existing mains/risers were replaced. It is unknown whether these are galvanized as no insulation was removed. 4. There is a gas-fired domestic water heater located in the mechanical room on the ground floor that was installed in 2002. The domestic hot water heater is connected to a separate storage tank that was replaced in 2016. It was noted during the walkthrough Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 2 of 7 that there is a small water heater in G08 Fitness Suite, but we were not able to gain access. The main building domestic hot water has a hot water recirculation system. 5. The grease interceptor is located in the mechanical room, and a sewage ejector pump is also located in the mechanical room. 6. There is a water softener located in the mechanical room that serves the hot water system. D. HVAC (Heating, Ventilation, Air Conditioning) 1. The ventilation system appears to have been completely renovated in 1979 with new ductwork and piping at that time. There was an HVAC upgrade completed in 2008 that included replacing air handling units, new boilers, a new chiller, new variable air volume (VAV) boxes that replaced reheat coils, and new chilled water and heater water piping required to support this project. The majority of the new piping was confined to the mechanical room in the 2008 project. The zoning of the building could be improved but would be most cost effective to occur during a renovation, so we have not included additional zoning in this report. 2. The boiler system consists of two Aerco Benchmark 1,500,000 MBH gas-fired condensing boilers with two associated Bell & Gossett distribution pumps. Heating water is distributed to hot water heating coils at the air handling units, VAV reheat boxes, and some perimeter heat. 3. The air-cooled chiller is located on the roof. It is a Carrier unit of 110 tons of cooling chilled water system serving the air handling units. 4. There are three air handling units that were installed in 2008. 5. Air handling unit (AHU)-1 serves ten VAV boxes that serve the basement/ground floor. The unit has a chilled water coil, hot water coil, supply fan with variable frequency drive (VFD), economizer, and filters. 6. AHU-2 serves the kitchen. The unit has a chilled water coil, hot water coil, and filters. The unit is 100% outside air. The supply fan has a VFD and appears to run at 50% capacity when the kitchen hoods are off and at 100% when the kitchen hoods are on. 7. AHU-3 serves First Floor, Second Floor, and the Mezzanine with eight VAV boxes for individual space control. The unit has a chilled water coil, hot water coil, supply fan with VFD, economizer, and filters. 8. There were a few areas reported as cold during one of our meetings with the City. One area is the northwest corner of the building near Room 205. It appears the thermostat is located in Room 208. Normally, a corner room would ideally be its own zone. The facility Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 3 of 7 can either add supplemental heat to the space or determine if the VAV box and reheat coil are functioning properly. 9. The Skywalk has a condensing unit on the roof and, we assume, a fan coil located above the ceiling, but we were not able to access. Maintenance staff stated the unit does not function properly on a consistent basis. 10. A Honeywell direct digital control (DDC) control system was installed in 2008 with the rest of the HVAC system upgrades. 11. Miscellaneous a. It was noted the compressors located in the mechanical room for coolers have not worked for a couple years. This is not an HVAC item and the facility should evaluate whether coolers are still needed. b. There could be asbestos on some of the piping or equipment insulation that is existing. The Owner should review asbestos and abatement requirements, as it is not part of this study. E. Electrical 1. Lighting a. In general, lighting fixtures in the building use fluorescent lamp technologies. Accent lighting fixtures use incandescent lamping. Light fixtures in some minimal areas have been upgraded to LED. Fixtures are in good condition and do not necessarily require replacement; however, upgrading to LED building-wide is recommended to achieve the desired energy goals. b. Exit signs appear to be LED and in decent condition. Exit sign batteries were not tested, and signs in areas being renovated should be replaced. c. Emergency lighting is supplied by a combination of building fixtures with emergency batteries and emergency battery standalone wall packs. Emergency lighting in most areas did not appear to be adequate. Exterior egress lighting at the main entrances is lacking, but the back entrances off the alley appear sufficient. d. Lighting controls are all manual and will require upgrade for all areas renovated to comply with current energy codes. Additionally, building-wide lighting controls are recommended to achieve the desired energy goals. Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 4 of 7 2. Power Distribution a. The existing main electrical switchgear is centrally located in the main mechanical room on First Floor. The gear uses antiquated fused switch technology; however, it is in good condition. The main system is 208/120-volt and rated at 1,200A. No revisions for the main gear are required for any short-term revisions, but when major renovations occur or changes to the mechanical systems happen it will be required to upgrade the existing switchgear and increase the electrical service to the building. b. Distribution equipment is located throughout the building. In general, the existing electrical gear is in good condition and can be reused for all renovations. The gear includes distribution panels, step-down transformers, and branch panelboards. 3. Fire Alarm a. The existing horn/strobe addressable system was replaced approximately five years ago. b. The existing system meets the current needs of the facility, is in good working order, and was observed to meet current codes. c. One exception is in the existing kitchen. The existing exhaust hood did not appear to have a fire suppression system and was also missing the required electrical shutdown for equipment under the hood. These code-required safety measures will be required if the kitchen is renovated. F. MEPT Recommendations (Mechanical, Electrical, Plumbing, Technology) 1. The City has stated that the building will likely require a multi-phased approach over approximately a ten-year period. The City expressed the desire to improve energy efficiency to align with their overall goal of moving closer to carbon neutral in the future. The existing HVAC will be approximately 23 years old in the next ten-year timeframe, which aligns with the typically expected life span for most of the equipment, making the replacement of this equipment more viable. Therefore, the direction was provided to include the recommended systems in the Energy Analysis portion of the report, including a variable refrigerant flow (VRF) HVAC system for most of the building and converting remaining HVAC and plumbing equipment to all electrical to alleviate the usage of natural gas. 2. The most cost-effective and efficient replacement is to replace the systems and complete the renovations as a single project within the building. However, we understand the project will likely need to be phased due to operations and budgets. The Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 5 of 7 HVAC system is anticipated to be converted in phases corresponding closely to the project phases that have been identified. There may be other areas of the building that will be impacted outside the scope areas of the individual project phases identified in the architectural portion of the report to allow for the HVAC system to be converted, as the existing HVAC system layout doesn’t exactly align with the planned project phasing. Design work will need to occur within the individual projects to determine how to approach these changeovers. 3. Plumbing and fire protection systems will be modified and updated during the individual phases of the projects. 4. Electrical systems will be modified and updated during the individual phases of the projects, however the main electrical system will need to be updated during one of the first major renovation projects when the new HVAC systems begin. It appears that the kitchen project may be the most appropriate. G. Energy Analysis - 45% Energy Reduction 1. General a. The baseline for the existing building was established by using the 2019 energy utilization numbers included in the City of Iowa City Facility Energy Assessment provided to IMEG. The site Energy Use Intensity (EUI) is 176. The goal of the reduction requires the source EIU to be reduced to approximately 108 EUI. 2. Mechanical a. In order to achieve a 45% reduction, all energy-related mechanical systems that can be upgraded should be. These include: 1) Gas consumption has increased by approximately 50% usage from 2018 and 2019. It needs to be determined why the gas usage is so much higher and take corrective action. 2) Retro commissioning is an option to go through the existing systems and controls to help identify what is causing some of the gas issues. This should include confirmation of economizer sequences on AHU-1 and AHU-3. 3) Review usage of the kitchen. Maintenance staff mentioned AHU-2 operates as constant volume. The unit has VFD, and control on the 2008 drawings call for fan speed to vary based on whether the kitchen hood is on. If the Kitchen is not currently being operated as a full kitchen, operating the large hood and making up that amount of air is a waste of energy. Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 6 of 7 4) It is not clear from the control shop drawings, but schedules and reset schedules should be implemented if they currently are not. 5) Setpoint adjustment controlled via occupancy sensors. 6) Other items that could be implemented to gain additional energy efficiency savings, but are not included to obtain the 45% reduction, are demand control ventilation and heat recovery. 3. Electrical a. In order to achieve a 45% reduction, all energy-related electrical systems that can be upgraded should be. These include: 1) Full LED lighting upgrade throughout. 2) Energy efficient lighting controls, including dimming, occupancy sensors, and daylight sensors. b. Some consideration should be given to installing rooftop solar photovoltaic systems. A structural analysis may be required to determine if the roof can support the ballasted panel racking system. 4. General Construction Items a. Kitchen revisions are anticipated in the master plan. The costs assumed with the revising the kitchen systems beyond what is noted in the mechanical above are assumed to be in the renovation costs. H. Energy Analysis - NetZero 1. Mechanical a. To reach NetZero status, all mechanical items listed above in the 45% carbon emissions reduction section would need to be achieved. Additional items to be considered should be: 1) Replacing the existing HVAC system with an all-electric system. Provide an air-cooled VRF HVAC system or similar efficiency. 2) Replace the existing gas-fired water heater with electric. 2. Electrical a. To reach NetZero status, all electrical items listed above in the 45% carbon emissions reduction section would need to be achieved. Additional items to be considered should be: 1) Building-wide automated shade controls 2) Offsite solar photovoltaic systems 3) Offsite wind generation 4) Purchasing green power credits Infrastructure Study for Iowa City Senior Center IMEG #20001495.00 Page 7 of 7 b. NetZero buildings require a certain commitment from the building occupants. In the case of lighting controls, it requires the occupants to be diligent in turning off lighting when not used, reducing the light in any given space often to a level lower than average. Given the transient occupancy of this building, it is unlikely that portion of the goal can be easily achieved. 3. Target EUIs Prepared by: Brandon W. Pierson, PE, LEED AP, Matt D. Snyder, PE, LEED AP BWP:MDS/dks \\files\Active\Projects\2020\20001495.00\ReportsNarratives\20220105 Rpt Iowa City Senior Center.docx Baseline Design Target Carbon Neutral Consumption On Site PV Off-site renewables/ Carport PV Carbon 0 0 50 0 0 - 176 86 50 348 183 0 EUI EUI EUI m.tons m.tons EUI