Inverter Scroll for Heat Pumps
Inverter Scroll for Heat Pumps

LUCERNE, SWITZERLAND, July 12, 2011— The new ZHW compressor from Emerson Climate Technologies is the first variable speed Copeland Scroll™ compressor with an inverter. For air-source heat pumps in particular, manufacturers can offer new options for increasing efficiency. This device uses a new motor technology.

The results are very promising: after Emerson Climate Technologies became an industry partner of the Lucerne University of Applied Sciences and Arts (HSLU) in Switzerland in August 2008, numerous laboratory tests confirmed the potential of the variable speed Copeland Scroll™ compressor. The project called “Efficient air/water heat pumps with continuous capacity modulation,” is funded by the Swiss Federal Ministry for Energy and promotes benchmark technologies. HSLU researchers were able to verify that the seasonal efficiency of contemporary air/water heat pumps, implemented in an optimized system and run with intelligent control strategies, could be increased by between 20% and 50%, depending on the application. The overwhelming share of these efficiency gains was possible due to optimized compressor technology. This means that most renovations in the gigantic renovation market could include air-source heat pumps. The long-term goal to move away from oil and gas to renewable energies in the heating market can therefore be achieved much more quickly.

Year-round Operation

The ZHW scroll compressor used in the HSLU project incorporates the latest advances in different technologies. A new brushless permanent magnet motor with a highly efficient drive enables the continuously variable adjustment of the compressor speed between 1800 and 7000 rpm. The required heating capacity can be tracked with pinpoint precision during the heating period. Even monovalent operation is possible when using air as a heat source thanks to refrigerant vapor injection technology, also developed by Emerson. On the coldest days of the year, this enables a condensation temperature of nearly 65°C with an evaporating temperature of -30°C. In other words: even at an ambient temperature of
-20°C, the heat pump can still provide the required temperatures for hot water and radiators. The optimum condensing temperature is 68°C – currently the highest possible value on the market for R410A refrigerant. The inverter, aligned with the scroll, meets all of the requirements for electromagnetic compatibility and other major guidelines for use in the building sector. Two models will initially be offered: the ZHW16 followed by the ZHW08; it will be possible to cover a heating capacity range of between 2 and 16 kW in the near future.

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About Emerson
Emerson (NYSE: EMR), based in St. Louis, is a global leader in bringing technology and engineering together to provide innovative solutions to customers through its network power, process management, industrial automation, climate technologies, and appliance and tools businesses. Sales in fiscal year 2010 were US$21 billion. For more information, visit

About Emerson Climate Technologies
Emerson Climate Technologies, a business of Emerson, is the world’s leading provider of heating, ventilation, air conditioning and refrigeration solutions for residential, industrial and commercial applications. The group combines best-in-class technology with proven engineering, design, distribution, educational and monitoring services to provide customized, integrated climate control solutions for customers worldwide. Emerson Climate Technologies’ innovative solutions, which include industry-leading brands such as Copeland Scroll™ and Alco Controls, improve human comfort, safeguard food and protect the environment. For more information, visit

Achim Frommann
Media, Communication & Relations
Emerson Climate Technologies GmbH,
Pascalstr. 65, 52076 Aachen, Germany
T: +49 (0) 2408 929 0
F: +49 (0) 2408 929 570