Brochure

Savings on service
and maintenance costs
HVAC units often operate under harsh conditions that can affect the lifetime and
reliability of the unit itself: Frequent on/off cycling, high ambient start-up, defrost
mode, low superheat conditions, high ambient operations, oil equalization and oil
return at part-load operations can all have severe effects on the entire lifetime and
compressor applications.
Danfoss scroll DSH:
a new level of
compressor
robustness and
system reliability
Danfoss has over 15 years of experience
in R410A scroll compressors and billions
of compressor operating hours in chiller
applications worldwide. Building on this
knowledge, Danfoss reliability and R&D
teams use advanced statistical tools
and psycrometric laboratory tests to
study and measure the implications of
system operations in critical conditions
on compressor reliability. This has
enabled Danfoss to develop the
necessary countermeasures to improve
compressor durability in many different
applications. The new generation of
DSH Danfoss scrolls include several
new and innovative features to improve
compressor and system robustness.
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1. Intermediate Discharge Valves:
Reduce the load on mechanical parts
at start up, provide safer operation
at high condensing and evaporating
temperatures and contribute to
better liquid management
2. Surface coating on thrust
bearing and polymer bearings:
Improves compressor robustness in
low lubrication conditions (start-up)
3. Organ pipe:
Maintains safe oil level at part-load
in manifold configurations
For DSH Large 20 to 50TR (240 to 600):
4. Integrated discharge
temperature protection*:
Prevents operation outside the
operating envelope
5. Integrated Non-Return Valve*:
Reduces refrigerant migration from
high-pressure to low-pressure side
after compressor shutdown
6. Modified gas flow path (Snorkel)
and sealed lower bearing:
Improves flooded start capabilities
and overall compressor robustness
against liquid slugs
Additional Reverse Vent Valve on
DSH 090 to DSH 184 prevent from
reversed rotation in case of wrong
phase connection
12 Compressors for Commercial Air Conditioning