An example of modular condenser coils.
Technicians know that condenser coils come in all sorts of configurations - some more challenging to deal with than others. But no matter the design, manufacturers have a goal to create the most energy-efficient and effective way to create cooling.

One newer approach involves modular condenser coils designed so each of up to 14 refrigeration modules utilizes an individual coil section. That method comes from New Albany, Miss.-headquartered Master-Bilt, which is using the design in its MRS series modular multi-compressor refrigeration systems. The purpose, according to the company, is to reduce heat and noise in such places as fast food restaurants, convenience stores, hotels, and other foodservice operations.

"By remoting all refrigeration systems in establishments - including those in reach-ins, walk-ins, and ice machines - to a single MRS system, business owners can remove the heat produced by multiple refrigeration systems from their kitchen or store and reduce their air conditioning load," said Bill Huffman, Master-Bilt's vice president of sales and marketing.

"This outside system, typically roof-mounted, also reduces noise level and extends the life of equipment."

Each system is composed of up to 14 individual modules, including a compressor and refrigeration components prepiped to a condenser coil.

These modular condenser coils are designed so that each refrigeration module utilizes an individual coil section. If necessary, a coil section can be replaced without shutting down the entire system, said Huffman. The compactly stacked condensers are sized for 110 degree F temperatures.

MRS units are prewired to an electrical panel for one-point connection. Each module is protected in cold weather conditions by integrated low ambient components, including condenser flooding valves and crankcase heaters. The systems are pre-piped to a central location with a single roof penetration point.

Said Huffman, "The modular design maximizes configuration flexibility, simplifies service, and provides for future expandability."

In Control

As an option, the company has an electronic control system that can be integrated with the MRS units. Master Controller is factory mounted to walk-in evaporators and is designed to lower the number of required defrosts and increase the reliability and simplicity of the system.

The system replaces many mechanical components with solid-state components, including an electric expansion valve that precisely controls the flow of refrigerant. Reverse cycle defrost is an option. This process (which is patent pending) involves a refrigerant reversing valve that is added to the condensing unit in walk-in coolers and freezers.

During defrosts, the valve reverses the refrigerant flow, and uses the system's hot gas to heat the evaporator coil along its entire length in order to eliminate frost buildup efficiently. This method is said to provide up to an 80-percent reduction in defrost energy usage when compared to electric defrost evaporators.

For more information on Master-Bilt's product line, or for literature, call Mary Lowstuter at 800-647-1284, ext. 4203, or e-mail to

Publication date: 06/06/2005