A split ductless A/C system as well as VRF zoning helped Guild Hardy Architects PA achieve LEED® certification, reduce energy bills, improve IAQ and room comfort levels at its new headquarters.

A Mississippi Second

“When we started designing our own headquarters several years ago, we knew that it was imperative for this building to exemplify sustainable, green-friendly design and to be a showcase for LEED®,” GHA partner and LEED accredited professional Mark Lishen, AIA, said. “We are an active member of the United States Green Building Council, and we have an obligation to put our best foot forward to demonstrate we care about the environment in which we live and build.” The building was the state’s second building proposed for LEED certification.

David Hardy, AIA, vice president of GHA, had been introduced to Alex Weddington, vice-president, General Supply & Machine Co., Inc. (GS&M), located in Meridian, MS through another project for the Jackson County School District. Hardy was impressed with the Mr. Slim® split-ductless A/C systems and technology from Mitsubishi Electric HVAC installed in 282 Jackson County classrooms. Hardy invited Weddington to get involved with the HVAC specs for his new building headquarters.

“It was rewarding to work on HVAC specifications with architects interested in LEED certification and dedicated to cutting-edge technology for energy efficiency and environmentally friendly design,” Weddington said.

 “GHA’s staff was immediately drawn to the Mr. Slim split-ductless cooling and heating systems. These systems include the inviting design of the indoor units, which fit elegantly and quietly into the spacious, soaring indoor working spaces of the new headquarters building.”

Weddington also recommended that GHA invest in CITY MULTI® variable refrigerant flow zoning (VRFZ) systems run by and energy efficient INVERTER technology. For his contractor, Weddington turned to 25-yr HVAC veteran, Darrell Suber, president, Southland Heating and Air Conditioning, Inc., Long Beach, MS. “GHA specs many LEED-type projects, and this headquarters will sell a lot of exceptional HVAC designs,” Suber said.

The LEED® Role
Lishen said CITY MULTI’s innovative design played a vital role in helping GHA meet the strict certification requirements demanded by the USGBC’s LEED Rating System 2.1. He summarized the following:
  • In the Energy and Atmosphere category, CITY MULTI helped meet three prerequisites: Commissioning allows for easy testing, setting, and adjusting of the entire system; Minimum Energy Performance maximizes energy performance by the use of VFDs in the compressor and outdoor fans, plus the ability to simultaneously cool and heat; CFC Reduction in HVACR Equipment – R-22 refrigerant is an HCFC and is not considered a CFC.
  • In the Energy and Atmosphere category, CITY MULTI helped GHA apply for critical LEED credits: Optimize Energy Performance (worth 2 to 10 points), which reduces energy costs by use of an INVERTER drive on the compressor, a VFD on the outdoor fans, variable refrigerant flow through the indoor units, and simultaneous cooling and heating with CITY MULTI.
  • In the Indoor Environmental Quality category, CITY MULTI helped GHA apply for critical LEED credits like Minimum IAQ Performance with Increased Ventilation Effectiveness (worth 1 point), and Indoor Chemical & Pollutant Source Control (worth 1 point) since the indoor units are zoned so they do not cross-contaminate zoned air.

Reduced Energy Bills

“We easily are able to manage the programming of all units from a PC in my office. The result has been effective use of energy resulting in reduced energy bills,” Hardy said.

He added that besides the ease of installation, CITY MULTI and Mr. Slim systems offer other distinct benefits as well. He cited the reliability and quietness of both indoor and outdoor units (outdoor units can be mounted directly under office windows without any distraction); the moisture-removing dry mode results in much improved IAQ and room comfort levels (necessary 11 months out of the year in coastal areas); the effective reverse heat pump cycle which warms the rooms on the few cold days of the year; and the huge energy savings realized within the first 12 months of operation.

“We have been so impressed with the performance and ease of operation of these systems that we look forward to specifying them on many of our future projects,” Hardy said.ES