It’s no mystery getting to the hearts and minds of consumers today. Offer them comfort, convenience, value, and reliability.

It’s true for homes, cell phones, and automobiles. And it’s becoming increasingly true for air conditioning systems.

The emerging high-end air conditioning systems marketplace already offers an exciting new era for equipment manufacturers and the consumers they serve. But it presents a unique challenge for the hvac industry: how to best serve the needs of luxury-minded consumers.

The emergence of modulated scroll systems will play an increasingly key role in this marketplace.

Modulated scroll systems offer the features and benefits consumers are seeking. But a system cannot truly modulate without a modulating compressor.

What is modulation?

Modulation makes it possible to tailor compressor performance to changes in ambient conditions, eliminating big swings in temperature and rh levels throughout a house.

Modulation adjusts the compressor capacity to closely match cooling demand. A modulated compressor will operate at a reduced compression ratio, reducing energy consumption.

Also, because a modulating compressor tracks the load more closely, it will cycle on and off less frequently, thereby increasing the amount of moisture removed from the air.

Modulated technology is not a new concept. Copeland Corp., for example, has been using a modulated concept in its reciprocating compressors since the mid-1980s. The company also has applied modulated technology to its family of scroll products.

Today, the first platform of modulated scroll technology is available from Copeland, and there are plans in place for enhancements over the next several years.

The manufacturer’s two-step scroll operates at full or 65% capacity by varying the flow of gas through bypass porting. The compressor can switch between modulation modes, reacting to changing conditions while the motor continues to operate at a constant speed.

The design eliminates the need for modulation-specific motor switching, thereby avoiding compressor cycling. A demand-based signal from the system directs the internal compressor-modulating device to switch capacity positions.

The industry already recognizes that scroll compressors deliver reliably under demanding conditions. Modulated scroll compressors bring even higher levels of reliability. And because of their simple design, scroll compressors have long operating lifetimes.

Modulation further increases the scroll’s reliability by reducing the number of on-off cycles, which reduces stresses associated with startup and shutdown, and significantly reduces wear of major load-bearing components within the compressor.


Customer comfort doesn’t equate to temperature alone. It also means quiet operation. While scroll technology inherently delivers quiet performance, modulated scroll compressors operate with even less noise at part-load conditions.

Clean air also can affect comfort for luxury hvac system owners, who want an atmosphere free of ozone-damaging chlorine.

While today’s modulated designs use R-22, upcoming generations of modulated scroll compressors will accommodate R-410A. This HFC refrigerant is well suited for modulating compressors, because its energy efficiency improves as the compression ratio decreases during reduced load operation.

Finally, manufacturers and consumers expect a compressor that is simple to apply and operate. Modulated scroll compressors can offer greater simplicity than reciprocating designs because they require no special motor, no start kit, no logic controllers, and no time delay.

Simplified installation and maintenance allow a/c equipment makers to deliver market-enhanced comfort and efficiency in a cost-effective package. And consumers receive a system that requires little attention in the way of manual operation and temperature adjustments.


Each evolution will make it easier to integrate modulated compressors into luxury a/c system designs.

According to Copeland, tomorrow’s modulated scroll compressors will include integrated controls, advanced motor designs, and multiple capacities down to 10%. Engineers are already working with Copeland’s sister company, Emerson Motors, to identify and test a variety of new technologies.

Designs are likely to offer features such as variable mechanical modulation and advanced motor drive technology.

As modulated scroll technology continues to advance, consumers will find air conditioning systems that are closer to true variable capacity and reaching higher levels of efficiency.

Just as important, these enhancements will continue to keep modulated designs top-of-mind with consumers who are looking for the ultimate in luxury air conditioning.