A first generation version of the Turbmiser chiller recently installed at The Dorchester in London is saving the
hotel £10,000 a month in energy costs. The Turbomiser II takes this performance to a higher level still.
The super-frugal Turbomiser II machine is the fruit of a two-year development programme by UK companies Klima-Therm
It has been heralded as “probably the most efficient HFC-based air-cooled chiller in the world,” able to achieve
EERs of 10 and above without the need for additional free-cooling circuits with expensive glycol. This saves both on
initial cost and ongoing pump energy.
The technology can reduce end users’ power bills by between 30 and 50 per cent - while at the same time dramatically
cutting carbon emissions. On some applications, the saving can cut pay-back time to less than a year.
The performance claims have been independently verified by leading consultant Mike Creamer of Business Edge Ltd,
using the ClimaCheck plant performance analyser at the Geoclima’s test facility in Italy.
As a result of its innovative design, the machine requires between 30-50 per cent less refrigerant than comparable
conventional chillers, reducing servicing costs and potential environmental damage from large-scale leakage.
Ken Strong, managing director of Bristol-based Cool-Therm, said: “The energy performance is staggering. These kind
of savings are unheard of with conventional technology, and it gives end users a decisive advantage in terms of
running costs. And the savings go on accumulating throughout the life of the plant.”
The chiller uses a combination of high efficiency components and technologies, combined with a highly sophisticated
adaptive control system that integrates and optimises performance.
Key design features include:
• Micro-channel aluminium condensers, that reduce refrigerant charge while increasing the effectiveness of
• Flooded evaporators that ensure optimum energy transfer between refrigerant and water;
• Inverter-controlled Turbocor compressors whose output can be precisely matched to load; and
• Use of a liquid refrigerant pump system that significantly increases thermodynamic efficiency across the
chiller’s operating range.
An important aspect of the control philosophy is that the system is designed to operate with a floating head
pressure, providing opportunities for savings not available to conventional designs. Unlike standard chillers whose
head pressure is fixed, the Turbomiser II chiller constantly self-regulates and optimises its performance in
response to ambient conditions and load.
This is achieved with the use of the 1kW liquid pump system, under the control of some highly sophisticated
electronics. This effectively increases capacity at all condensing temperatures, but has greatest effect at lower
temperatures. As a result, it can deliver refrigerant many times more efficiently than a compressor.
Another key to the chiller’s ultra-low energy consumption is the fact that the compressor does not have to run
constantly to maintain a fixed head pressure. By using the liquid system at lower ambient temperatures the
compressor(s) can be switched off, while the liquid pump circulates refrigerant around the system. This glycol-free
alternative to conventional free-cooling is highly efficient, and dramatically reduces energy consumption while
maintaining refrigeration performance.
A secondary benefit of the reduced compressor run-time is extended plant life. With the low-power liquid pump taking
the load, the compressor does not have to work so hard or for so long, reducing wear and the likelihood of
As a result of its innovative design, the Turbomiser II can halve the energy costs compared with a conventional
screw-based machine, according to the companies behind it. On many applications, this can cut payback time to less
than one year.
It is being targeted at building owner-occupiers for whom rising power bills and the need to cut carbon emissions
are key factors in buying decisions. It is expected that the Turbomiser II will prove a compelling choice for those
having to replace aging, inefficient machines running on R22.
The chiller is available in capacities from 250kW to 1.5MW, and can be applied in most commercial and industrial
applications. It is ideal for data centres, large retail developments and deep plan buildings that have a constant
base load. Hospitals and hotels with their need for all-year-round cooling, are also excellent applications.