SUMMIT, NJ — Eight outdoor units or one? Sixteen refrigerant line penetrations or two? The choices looked like a no-brainer for a contractor installing ductless air conditioning in Overlook Hospital’s Sleep Clinic: the fewer, the better.

Contractor Ken Grabowski, president of Airetech Inc., Fanwood, NJ, first bid on the job with a standard ductless design (the eight and 16 layout mentioned first). When he found out about the advantages offered by a new ductless system and bid based on that system, the job was Airetech’s.

Having a single outdoor unit instead of eight is more pleasing aesthetically for the owners, Grabowski pointed out, and has benefits in reduced maintenance and wiring. And when maintenance and wiring take less time, they generally cost less.


The new ductless system, Sanyo’s Eco Multi, was designed to be flexible, states the manufacturer, calling it “a high-concept solution designed specifically for commercial applications, with special emphasis on the renovation of older buildings.”

Paul Drosness, regional sales manager for Sanyo Air Conditioning Systems, further explained that “We have not taken a multi-evaporator design and shoehorned it to fit a commercial environment. Eco Multi has been carefully designed from the ground up to be the most flexible and customizable commercial solution available on the market today.”

Eco Multi’s design makes it possible to connect a series of multiple indoor evaporator units with a capacity of up to 135% of the outdoor condensing unit’s maximum capacity, the company explains. With an indoor unit of 12,000 Btuh (like those installed at Overlook Hospital, for example), a contractor can connect as many as eight indoor units to one outdoor condensing unit — which is precisely what Airetech did.

Some commercial-industrial applications benefit particularly from the system’s refrigerant circuit; it is designed to operate without an inverter control, therefore decreasing harmful electromagnetic disturbance (harmonic current emissions), in compliance with EMC standards.

The system’s flexibility comes largely from its design, which combines a standard compressor and a newly developed, dual-cylinder power control compressor. This twin-compressor design can respond to capacity requirements by modulating the output of the compressor; an external save (bypass) valve gives this system eight-step compressor capacity control, the company says.

Operating capacity of the power control compressor can be stepped in 12.5%, 25%, 37.5%, 50%, 62.5%, 75%, 87.5% and 100% increments, the company continues, using a 16-bit microprocessor to ensure a more stable room temperature at a constant airflow rate.

A variety of evaporator configurations for Eco Multi (wall, ceiling suspended, and ceiling recessed mount) add to the unit’s application flexibility. In addition, a new “concealed-duct type” evaporator can be used for 2- and 3-ton stand-alone heat pump systems, as well as Eco Multi.


A lot of careful design planning goes on before most installations that look simple. The Overlook installation was no exception, especially where the refrigerant piping was concerned, says Grabowski. Airetech worked in concert with Sanyo and United Refrigeration Inc. (Union, NJ), to make sure this job went without a hitch.

The sleep clinic previously had PTAC units that were original to the building, which was built in the 1970s, Grabowski said. IAQ was not a particular concern for this new installation, he said, because the entire building has central makeup air exhaust. If it had been an issue, however, the Eco Multi can be hooked up for fresh air exchange, the contractor said.

There was a single indoor unit for each 300-sq-ft (approximate) clinic room, wired and piped to the single outdoor unit. Each indoor unit could be recessed in the ceiling, Grabowski pointed out, where those fewer piping connections would be particularly beneficial.

Determining the exact refrigerant piping calculations is critical, Grabowski said. Once his company had finished connecting the tees to each air handler, the exact length of piping had to be given to the manufacturer for the refrigerant charge, Grabowski said. Sanyo helped the company determine this and other piping calculations.

Figuring this exactly is worth the extra time it may take, because done correctly, “There’s no need to put gauges on for this unit’s installation,” Grabowski said. A contractor still needs to pressurize the system to check for leaks, he added. The system is charged with R-22.

On start-up, the contractor only had to adjust each thermostat for each unit to start up, Grabowski said. The system uses Sanyo thermostats. The units also can be controlled remotely. The wiring is relatively simple, the contractor said. “What’s tricky is the piping.”

At a sleep clinic, however, the facilities people were more likely to be concerned with noise than anything else. The units meet the facility’s required noise level, Grabowski said. “It has been in operation and there have been no calls on it,” he said — which is as it should be.

For more information, contact Paul Drosness at 518-330-6433.

Publication date: 06/17/2002