Client: OSF St. Francis Hospital
Project: Gladstone Medical Office Building
General Contractor: Brinkmann Constructors
Floor Area: 18,145 sf
Construction Schedule: June 2017
HVAC Contractor, Engineer of Record
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.
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.