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Item No: 7H Meeting Date: October 24, 2011 Type of Business: Council Business Administrator Review: ____ City of Mounds View Staff Report To: Honorable Mayor and City Council From: Don Peterson, Public Works Supervisor Item Title/Subject: Resolution 7848, Approving a Contract with Architect Mechanical Inc. for Heating Improvements at the Public Works Maintenance Facility Background: The Public Works Maintenance Building was originally built around 1952. An addition was added to the building in 1987 to address space and operations issues. The heating system for the entire building involves a number of different systems. The office areas of the original building are heated with a hot water (base board) radiant heating system, while other “non-office” areas of the original building heated with natural gas ceramic heaters that hang from the ceiling. These ceramic heaters were used successfully for many years, but in the 1990’s, parts became obsolete and it became cost prohibitive to repair them or replace them in kind. A few of the heaters were also “red tagged” (taken out of service) due to ceramic coils leaking natural gas. The heating system was finally shut down in 2000 and gas supply removed to the heater units. The hot water heat system for the office areas is still in use. Heat for the 1987 addition was provided by a forced-air system in office areas and natural gas unit heaters in non-office areas. The natural gas unit heaters were converted to burn waste oil in 1989. The waste oil used to fuel these heaters was supplied from City vehicle maintenance operations and the general public via a used motor oil dumping station located in the yard of the Public Works Maintenance Facility. While this system helped to reduce the cost of natural gas for heating, it became unreliable and costly due to the uncontrolled waste being dumped into the waste oil tank. Although only used motor oils were allowed to be dumped, some of the general public found this was a good way to get rid of other undesirable fluids such as antifreeze, driveway sealers, paint, wood stain, and just about any other fluid taking up space in their garages. This cocktail mixture of “fuel” would often not flow through the jets of the burners properly, causing the jets to gum up and fail, which required hiring contractors for costly maintenance and repair. In addition, some of the waste that did burn did not burn cleanly and left bi-products such as thick smoke, silt, and ash inside and around the building. The waste oil dump was finally closed at the end of 2010 and the system is used on a limited basis with waste oil burned only from City operations. In response to the ceramic heaters being taken off-line in the original building and frequent maintenance and repair downtime (and cost) for the waste oil burners, a ceiling-hanging radiant tube heating system was installed in 2000. The system was installed in limited areas of the original building and 1987 addition, including the mechanic bay, wash bay, and the main shop. The radiant tube heating is very efficient and heats the surrounding surfaces under the heaters rather than the surrounding air, providing a much better heat recovery when the large bay doors are opened and closed. Unfortunately, the radiant tube heater did not extend into the main bay of the original building served by the old ceramic heaters, leaving a poorly heated environment to perform the duties that occur in that space during winter months. Discussion: Public Works staff has evaluated the heating and ventilation conditions in the Public Works Maintenance Building for quite some time. Most recently, staff contacted the contractor who performs routine maintenance on the building (Architect Mechanical) to evaluate the substandard