OSF Medical Office Building

Project Scope

Wiegmann was the engineer of record and designed an energy-efficient hot water reheat VAV system and a building automation system for this medical facility in Gladstone, Michigan. The new building, which replaced an existing clinic, provides expanded space for patient exam and treatment rooms, a lab, medical imaging equipment, and designated areas for occupational therapy, wound care and audiology services.

Project Challenge/Solution

The client wanted a cost-efficient, energy-efficient and long-lasting (20 to 30 years) HVAC system. The building structure was not conducive to roof-mounted HVAC equipment so we recommended a split system with an outdoor condensing unit on a concrete pad and refrigerant piping to an indoor air handler inside a mechanical room.

For longevity and easy cleaning, we specified a double-walled air handler with foam insulation, a rust-resistant stainless steel drain pan under the cooling coil, and a variable frequency drive (VFD) on the supply fan. The supply fan VFD upgrade allows the motor and fan to “soft start” for better efficiency and longer equipment life than a constant speed fan. Other energy upgrades included an airside economizer, high efficiency condensing boilers with 97 percent thermal efficiency, and Variable Air Volume (VAV) boxes with hot water heat , which is significantly more efficient than electric heat.

Energy Savings

Wiegmann performed an energy analysis on this $5 million medical office building and determined that an energy-efficient hot water reheat VAV system, though more expensive up-front, would return a simple payback of 7.9 years as compared to electric heat.