Adsorption chillers are hot topic

GERMANY: Adsorption chiller manufacturer InvenSor claims to be benefitting from growing interest in this efficient and environmentally friendly technology.

According to a new study by BP Energy Outlook, global energy demand is set to increase by up to 41% by 2035, primarily driven by rising demand in emerging nations like China and India. Chillers and air conditioners make up a very large proportion of the total energy consumption. InvenSor maintains that in Germany, for example, they account for around 15% of total end-use electricity consumption.

For this reason, eyes are turning to alternative technologies like InvenSor’s adsorption chillers which are powered by waste heat rather than electricity and use water as a refrigerant. The company reports that it has received more orders in the past six months alone than in the entire business year 2013.

A growing number of adsorption chillers are also powered by solar energy and being installed in warmer European countries Italy and Spain.

Sören Paulußen, InvenSor’s CEO, said “We’re seeing clear signs that there’s growing demand on the market for thermally powered chillers. There’s increased awareness among planners and installation companies. We are able to offer more and more attractive application options. We’ve been able to implement a series of exciting new projects at home and abroad in the past few months, especially in the area of industrial applications and solar cooling.”

There is a wide variety of applications for adsorption chillers in the 5-100 kW range. In Germany, most InvenSor chillers are used in trigeneration installations. These systems provide electricity, heating and cooling through a clever combination of combined heat and power units and adsorption chillers. The CHP units produce electricity and waste heat that can either be used directly for heating applications or for the chiller. Thanks to significantly lower CO2 emissions than conventional air conditioners, these systems protect the climate and environment.

“We are currently receiving a significant number of new orders from industrial companies, especially in the plastics processing industry where we are able to achieve very good annual operating hours of the chillers due to continuous operation of the processes, resulting in favourable payback time for the systems. It’s a very promising area of application for the future,” according to Niels Braunschweig, CEO and director of R&D at InvenSor.

InvenSor adsorption chillers come prepared for use as a heat pump and can include free cooling on cold days.

Safe harbour

Powered by vacuum tube collectors from Italian manufacturer Thermics Energie, an InvenSor adsorption chiller has been air conditioning the Portobaseleghe administrative buildings of the Bibione Mare private harbour and camping complex near Venice since 2013.

The 22kW capacity solar collectors provide enough thermal energy for air conditioning in the summer and heating in the winter. With a nominal power rating of 10kW, the InvenSor LTC 10 plus chiller was installed in 2013, replacing an inoperable absorber and, like the previously installed chiller, is powered by heat instead of electricity.

In Bibione, a large, 2,000 litre hot-water buffer tank stores the heat generated by the solar collectors until it is fed into the building heating system or used to power the adsorption chiller. A smaller, 750 litre buffer tank is also installed for cooling, providing reserve capacity when cooling demand is high. The system’s re-cooler was installed in a shaded passageway through the harbour building, which is why the system can withstand Venice’s warm climate with dry heat rejection.