ASHRAE Journal - February 2015 - 14

INDUSTRY NEWS

ebm-papst showed a new energy-saving fan purposebuilt for use in evaporators, saying it offers especially high
reliability and long service life. The fan has been designed
as a complete unit, helping it achieve a higher degree of
overall efficiency than standard solutions made up of individual components. The company's GreenTech EC technology and HyBlade impeller, with its aerodynamically optimized blade geometry, produce the high overall efficiency.
Another ebm-papst product launched at Chillventa
is the EC medium-pressure axial fan, a fully assembled
and therefore installation-ready combination of housing,
impeller, EC motor and control electronics. Different operating points can be set by way of speed adjustment. The fan
system is available in outside diameter sizes of 1120, 1250,
1400 and 1600 mm. The fans are used wherever high airflows must be conveyed against medium pressures. Typical
applications include heat exchangers and cooling towers,
but also evaporators like those found in industrial food
production.
For supermarkets, ebm-papst now offers a range of different configurations of energy-saving fans. The latest
solution is the handheld operating device. It enables two
pre-set speed levels for the energy-saving fans to be easily
adjusted or reprogrammed with the help of a user-friendly
navigation menu.
Carel exhibited its Heos controller for water loop systems. The product offers the simplicity of a water loop
system that is used as the transfer fluid for condensation
heat generated by small refrigeration units. It is installed
in self-contained plug-and-play cabinets equipped with
BLDC compressors. The use of horizontal BLDC compressors maximizes unit efficiency, while the wide range of
modulation of the Power+ dc inverter and the E2V stepper electronic expansion valve mean each individual unit
always operates in the best working conditions without
being affected by the others. Compressor and valve modulation, intelligently controlled by Heos, ensure perfect
control of food temperature, completely eliminating the
typical swings of remote systems, Carel says, while providing in-depth information on refrigeration system status,
applying advanced algorithms for preventive diagnostics
and maintenance.
Operation is completely monitored by the PlantVisorPRO
supervisory system, which displays only the main data
needed by specific types of users (energy managers, service
and maintenance, etc.) at a local and remote level, while
also allowing overall system efficiency to be optimized
according to the operating conditions of each individual
unit. The benefits are up to 85% less leakage, up to 70%
less refrigerant charge, and up to 20% energy savings.

ASHRAE JOURNAL

ashrae.org

FEBRUARY 2015

LETTERS

Revisiting Chiller Performance
I read with close interest December's article "AirCooled Chillers for Las Vegas Revisited" about a project that took place 11 years ago. I, too, had a project in
Nevada at the same time and urged the owner to accept
an air-cooled chiller, which they eventually did. This
article goes a long way in justifying that decision even
though we never kept such good records as the authors
did.
I remember the skepticism that was voiced in letters
to the editor after the initial Journal article came out
(which I have saved) over the application of air-cooled
chillers in such a climate. I very much appreciate the
detailed summary that vindicates the application of aircooled equipment (in a certain tonnage range) by eliminating intensive maintenance cooling towers, chemical
treatment and costs, additional pumps, piping and,
perhaps most important, savings of precious water.
Jacob Laete, P.E., Life Member ASHRAE, Spokane, Wash.

The Author Responds
We appreciate your letter and the fact that you are
pleased to see data that confirms our recommendation,
as well as yours, for a similar installation of an air-cooled
system in Nevada at about the same time.
To keep the record straight, we did not keep the energy
use and maintenance cost data over the past 14 years.
It was the Clark County School District (CCSD) that collected it. We had to work to obtain, verify and compile the
data in a meaningful way for the article.
A major reason for the success of the project's design is
that all air-handling units included a 100% airside economizer. In ASHRAE Climate Zone 3B, which is nearly all of
Clark County and the CCSD ABC Schools reported in the
three articles, there are 3,3xx days when the temperature
is 65°F or less and 1,7xx hours when the temperature is
less than 65°F during the hours from 8 a.m. to 6 p.m.
This represents nearly 20% of classroom occupancy hours
when mechanical cooling is not required. This opportunity for airside economizer operation only requires a
control system that is reliable and accurate if maximum
efficiency is to be maintained.
The data in the December 2014 article clearly indicates
where controls were fully functional. Scheduling equipment off during unoccupied hours was also important to
the success and efficiency of the ABC schools.
The savings in water by not using waterside economizers was a big plus for CCSD.
Ronald H. Howell, Ph.D., P.E., Donald W. Land, P.E. and John M. Land

ASHRAE Journal - February 2015

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