FEATURE
INCORPORATING COLD CHAIN
Reciprocating vs screw compressors
– how do you choose?
By Russell Hattingh, engineering manager at Johnson Controls Systems and Service, South Africa.
What would you choose for your HVAC&R applications: reciprocating or screw compressors?
The age-old debate continues.
vs
Reciprocating versus screw compressors — how do you choose?
T
here is no single answer to this question
of choosing between recips and screws
— it depends on the application,
operating conditions, and attitudes. New
recip advances may win these compressors
a few more converts, however …
In South Africa, as elsewhere globally,
there has been a move away from
recip compressors in the HVAC industry
for more than a decade, with scroll-
type chillers taking some market share.
Demand for recips is still high for certain
applications, such as cold stores and
process cooling, however.
The short answer is that each
compressor type has its particular
advantages, depending on the required
operating conditions.
To make an optimum selection, the
actual application conditions must be
analysed. Relevant criteria, such as required
capacity, operating conditions, part
load, energy consumption, temperature
levels, refrigerant, ease of maintenance,
investment, and available space should be
taken into consideration.
Let’s take a look at the fundamental
differences.
Reciprocating compressors: Recips are
piston-driven compressors delivering
stepped control with specific output
per piston. They work well in high-
temperature applications, delivering
energy savings. They typically use
ammonia refrigerant, which is in demand
COLD LINK AFRICA • July/August 2019
as it is considered a more naturally eco-
safe option. R&D by large manufacturers
for recip compressors continue to deliver
enhancements and new features that
keep the compressor evergreen.
Screw compressors: Screw compressors
offer a higher capacity output, larger
compression ratios, and smoother
control to deliver energy savings in large
applications. A later evolution of the
compressor, they are considered more
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