This is an excerpt from an article featured in ATMOsphere’s “Clean Cooling for Data Centers 2025” report, which can be downloaded here. ATMOsphere is the publisher of NaturalRefrigerants.com.
Jaeggi is a Swiss manufacturer of dry coolers and gas condensers, founded in 1929 in Berne. The company began producing finned heat exchangers for refrigeration systems in 1934 and later developed hybrid dry cooling technology, introducing its HTK hybrid dry cooler in 1988 and patenting the innovation in 1992.
The company was acquired by the Güntner Group in 1995 as part of a strategic move to expand the group’s advanced heat exchange and cooling technology portfolio, including hybrid dry cooling solutions. Since then, Jaeggi’s hybrid dry cooler technology has contributed to the broader Güntner Group offering for high-performance and mission-critical cooling applications, including early data center projects such as its first installation in 1996.
Jaeggi’s hybrid system works as an air-cooled dry cooler, with the heat exchangers wetted with water when the ambient temperature climbs or when high cooling loads are required. The HTK operates as a dry cooler until 18°C (64°F) and in wetting mode from 24°C (75°F) – these exact values depend on the location and load – with the temperature in between covered by either dry or wetting depending on the load. The HTK is available in 84 different models and has a capacity of 100–4,000kW (28–1,137TR).
“Chillers use six to ten times more power than our units, so even when they’re using them with chillers they should be using our unit to do all the hard work.”
Jeffrey Hargreaves,
Business Development Director for Data Centers at Jaeggi
1.8GW and counting
The HTK can be paired with chillers and either pre-cool or post-cool water or a water–glycol mixture coming from a data center. There are some instances where the HTK is solely used to cool a data center, such as in the Nordic countries and elsewhere in Northern Europe, according to Jeffrey Hargreaves, Business Development Director for Data Centers at Jaeggi.
While the HTK is often paired with chillers, a data center’s cooling system is typically designed to let the hybrid dry cooler handle as much of the cooling load as possible. “Chillers use six to ten times more power than our units, so even when they’re using them with chillers they should be using our unit to do all the hard work,” Hargreaves said.
Jaeggi is far from the only company that offers a hybrid dry cooler to data centers. Hargreaves acknowledged pressure from competitors but noted that the HTK is built to a “high spec.”
“It’s easy to put the bolts and physical structure together, but [competitors] don’t necessarily have the operational experience,” Hargreaves said.
Hargreaves said Jaeggi has worked on more than 200 data centers, which range in size from 300kW to 18MW, with a total installed IT power capacity for all projects of 1.8GW. The sector accounts for 40% of the company’s total business and 75% of its business by dollar value, with growth forecast at 30% year over year, Hargreaves said. The majority of its projects have been in Western Europe, the U.K. and the Nordic countries.
