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Item No: 71 Meeting Date: August 26, 2013 MOD � 7gtSVVfE_W Type of Business: Council Business lJjVjAdministrator Review: City of Mounds View Staff Report To: Honorable Mayor and City Council From: Nick DeBar, Public Works Director Item Title/Subject: Resolution 8145, Authorizing HVAC Improvements for the Event Center at the Community Center Background: The Community Center was constructed in three phases between 1997 and 1998. Construction for the center utilized portions of the existing Bel -Rae Ballroom building that occupied the site prior to construction. Unfortunately, there were a number of construction and design issues that occurred during and after construction of the facility for these and other reasons. Since completion, there have been many issues related to the HVAC system at the Community Center that have required many staff hours and expenses to diagnose and repair, with some that seem to reoccur for unknown reasons. In addition to spent time and costs to address these issues, there is an "inconvenience" cost with those that work, visit, or rent the facility spaces. At the time of construction, recommendations to revise HVAC equipment and systems were not considered by the City Council in response to a blown project budget and cost over -runs. Staff remembers being told by mechanical contractors on the job that the installed HVAC system "will never work right' for the space requirements. No building space has shown this to be true more than Zone 4 which encompasses the Event Center and adjacent hallways. This zone is served by a 15 -year old, 70 -ton, McQuay roof top unit (RTU) that is sized for full occupancy (400 persons) but has limited features for appropriate climate control. These inadequacies prevent the ability to keep humidity levels down and controlling comfort levels. In short, the RTU short cycles and compressors do not run long enough to dry out the indoor air before reaching the temperature set points. This results in the space being "cold and clammy" during cooling seasons and providing conditions ripe for mold and mildew to grow. This has resulted in expenses with mold removal in carpets and other surfaces on several occasions, including replacing the entire carpet on one occasion. In 2012, the HVAC ductwork was also cleaned and decontaminated and ceiling tiles replaced for a combined costs exceeding $50,000. Public Works has spent countless hours meeting with a number of mechanical engineering firms and mechanical contractors the past few years to address the HVAC deficiencies at the Community Center — with special attention to the Event Center indoor air quality. RTU#4 and associated controls have been inspected, tweaked, monitored, and adjusted to get things to work right. This work has determined that the equipment is working correctly and operating per manufacturer recommendations — which mean that the existing equipment will never work to provide a comfortable indoor air environment. Discussion: Public Works staff has been working with Trane US, Inc. on issues related to the HVAC deficiencies at the Event Center. Trane provided a proposal to upgrade the HVAC equipment to address ventilation, comfort, and humidity issues in the Event Center (Zone 4). The scope of work is as follows: 1. Replace the existing 70 -ton Rooftop unit with a Trane 50 ton roof top unit. The new unit was sized based upon space usage and updated energy codes. All calculations were verified by a third party engineering firm. 2. Genesis Air Cleaning will be incorporated into the ventilation system to provide active air cleaning measures that will provide better air quality to the space and to take advantage of