DETROIT INSTITUTE OF MUSIC EDUCATION
Retrofit Team
CONSULTING ENGINEER: Peter Basso Associates Inc., Troy, Mich.
MECHANICAL CONTRACTOR: Complete Mechanical Contracting Inc., Westland, Mich., (734) 729-5599
GENERAL CONTRACTOR: Sachse Construction, Detroit
ARCHITECT: Neumann/Smith Architecture, Detroit
SHEET-METAL CONTRACTOR: Ventcon, Allen Park, Mich.
HVAC CONTROLS INSTALLER: Michigan Environmental Controls Inc., New Hudson, Mich.
Materials
The light-load-bearing capacity of a 19th century timber roof dictated an innovative HVAC retrofit specification for a historic downtown build- ing renovation. After considering a myriad of conventional HVAC methods, George Hopkins, principal of Peter Basso Associates, chose comparably lighter-weight variable refrigerant flow (VRF) technology and unique rooftop equipment mounts with footings for strategic weight distribution. Both technologies also minimized roof penetrations from ductwork, curbs and more conventional labor-intensive fabricated I-beam supports, which ultimately saved tens of thousands of dollars.
To offset the roof’s weight-bearing limitations, the Peter Basso Associates team specified Big Foot Systems tubular, corrosion-resistant, hot-dipped galvanized modular steel equipment mounts. They support seven groupings of 20 CITY MULTI Series VRF condensers, ranging up to 325,000 Btu. The VRF condensers provide refrigerant to 39 fan coils that supply the majority of air conditioning and partial heating through open architectural ceiling, rectangular metal ductwork.
The equipment mounting system’s 12- by 12-inch-square anti-vibration nylon footing pads were strategically positioned over roof joists to preserve the roof’s structural integrity while supporting the VRF units’ distributed weight. The pads’ anti-vibration attributes are critical in minimizing noise transmission to the rehearsal and performance spaces, as well as the third-floor recording studio. “The anti-vibration feet allowed us to eliminate the expense of conventional spring isolators and other equipment,” Hopkins says.
Custom-designed for the project by the manufacturer’s in-house team, the equipment mounts saved the venture 30 percent in installation labor and materials versus traditional mounting methods, according to Robert Smith, project manager, Complete Mechanical Contracting.
Furthermore, the adjustable legs provided easy equipment leveling without the use of shims to accommodate the building’s roof slope of approximately 1 inch per foot. When the building is reroofed someday, roofing surfaces can be replaced underneath one leg at a time while the other three legs allow the units and piping to remain connected and functional.
The Peter Basso Associates design also uses a 7,500-cfm air-to-air energy-recovery ventilator (ERV) to supply outdoor air to each floor’s fan coil. The ERV return air is supplied by ceiling plenums, bathrooms and janitor-closet exhaust air. Peter Basso Associates located it on the third floor because of the roof’s weight limitations.
BIG FOOT SYSTEMS’ MOUNTING MANUFACTURER: RectorSeal Corp.
CITY MULTI VRF CONDENSERS AND FAN COILS MANUFACTURER: Mitsubishi Electric Cooling & Heating
ENERGY-RECOVERY VENTILATOR MANUFACTURER: RenewAire
NIAGARA CONTROLS MANUFACTURER: Tridium
CONTROL AND SENSING EQUIPMENT MANUFACTURER: Johnson Controls
The Retrofit
The 6-story, former Bamlet Building, owned and managed by Detroit’s Bedrock Real Estate Services, was designed of brick and timber in the Neoclassical style by famed architecture firm Spier & Rohns in 1897—long before specifications of cooling towers, chillers and other heavy rooftop HVAC systems were conceived.
Bedrock, which oversaw the 36,000-square-foot mixed-use space’s renovation, has invested more than $1.8 billion since 2011 in acquiring, renovating and developing more than 80 downtown Detroit properties. The strategy of retaining and preserving historic building features, such as with this building, complements the urban-style dining, shopping, technology, arts, business and residential environment Detroit-based Quicken Loans Founder and Chairman Dan Gilbert has envisioned and supported.
PHOTO: RECTORSEAL CORP.