(706) 724-5756  
Augusta, Georgia  

First City Multi^™ System in the CSRA Area Goes Into Operation At Beasley Broadcast Group, Inc.

The First variable refrigerant flow zoning (VRFZ) system in the CSRA area has recently been commissioned and is operating at the new combined studio building for Beasley Broadcast Group, Inc., on Jimmy Dyess Parkway in Martinez, Georgia.  The 19,000 sq. ft. building provides administrative and marketing offices, and broadcast studios for six local radio stations:  WGAC, WGOR, WRDW, WCHZ, WKXC, and WSLT.

The systems were designed by William J. Farmer, P.E., Mechanical Department Head at Johnson, Laschober & Associates in Augusta, Georgia.  Mr. Farmer is certified CITY MULTI™ VRFZ System Designer.  The building Architect was George R. Price, Jr.  The general contractor was R.D. Brown Contractors and the mechanical contractor was Southern Mechanical, a certified CITY MULTI installer.  The systems were supplied by Mingledorff's, Inc.

The CITY MULTI VRFZ systems are manufactured by Mitsubishi and distributed by HVAC Advanced Products Division of Mitsubishi Electric & Electronics USA, Inc., headquartered in Lawrenceville, Georgia.  CITY MULTI is an excellent zoning system and is the first simultaneous cooling and heating multi-split HVAC zoning system in the U.S. but the system has been used in other countries from almost 20 years.  The Beasley Broadcast building has four R-2 Series outdoor heat pumps, 95,500 Btu/h per unit, and 28 indoor fan coil units with 6 to 8 indoor units connected to each heat pump.  For each system, indoor and outdoor units are connected with refrigerant piping through a BC controller, which directs refrigerant flow between the outdoor unit and the indoor units.  This allows simultaneous heating and cooling while paying for the energy of only one or the other, i.e. heat is recovered from the areas in the building requiring cooling (interior zones) and directed to the areas requiring heating (perimeter zones.)  Simultaneous operations can occur anytime the temperature drops below 65 °F.  Each of the 28 zones has a thermostat connected to a central controller.

The outdoor heat pumps utilize inverter technology to vary the compressor speed to match the actual loads from the zones.  The controls of the CITY MULTI Controls Network operate the systems only at the levels needed which means the systems usually run continuously at very low speeds.  Not only does this provide excellent indoor comfort levels without wide temperature swings, it also reduces power consumption for energy savings.  The unique low-speed operation gives superior heating performance and the fan coil units do not require supplemental electric heat.  Four energy recovery ventilators are used to exhaust air from the building, recovering the energy and transferring it to the fresh outside air before being introduced into each fan coil unit. 

A critical design consideration for the studios was to provide a quiet HVAC system that would not interfere with the broadcast operations.  By using a combination of fan coil units, some ducted and some duct-less, sound levels from the units as low as 24dB(A) were obtained.  The outdoor units are also very quiet with ratings of 57dB(A), lower than most residential units.

Reliability of the CITY MULTI system is exceptional.  Due to the variable speed drive on the compressor, it starts on low-speed then ramps up to the required speed, which cuts down on compressor failures.  Over 100 systems have operated in Latin America for over 6 years with zero compressor failures.  CITY MULTI leads the industry with 5-year limited parts and 6-year limited compressor warranties.

For more information on the application of CITY MULTI for any building type, please contact Mr. Farmer at (706) 724-5756.