Bitzer Screw Compressor
Following up on your previous question about reciprocating compressors — screw compressors are the mainstream choice for medium-to-large pharmaceutical cold rooms (>300㎡). Here's a clear breakdown based on your scenario.
Full Product Line Overview (Cold Room Relevant)
Series Type Power Range Positioning Cold Room Suitability
CSH Semi-hermetic compact screw 40~240 HP Mainstay of commercial cold chain ✅ First choice for medium-to-large pharmaceutical cold rooms
HSK Semi-hermetic air conditioning screw 40~90 HP Medium/high temperature AC / cold room ✅ Fully sufficient for pharmaceutical storage (2℃~8℃)
HSN Semi-hermetic low-temperature screw 40~90 HP Low-temperature freezing Vaccine storage / ultra-low temperature backup
OSK/OSN Open-drive screw 84~250m³/h displacement Industrial refrigeration Large logistics cold rooms
VSK Hermetic screw 15~25 HP Small commercial Small pharmaceutical cool rooms
LT/MT/HP Screw CO₂ (R744) 200~1200kW Industrial / heat pump Trend for new green cold rooms
Naming convention: CSW37.2 = Single-stage (S) + Screw (W) + displacement 37.2m³/h; HSW = Two-stage; CW = Water-cooled
Key Parameters (What Matters for Pharmaceutical Cold Rooms)
Parameter Data
Refrigerants R134a, R404A, R507A, R449A, R744 (CO₂), R290
Evaporating temperature Single-stage down to -40℃ (pharmaceutical storage only needs 0℃, ample margin)
Compression ratio tolerance 12:1
Capacity control Step control 100%→75%→50%; CSW series supports continuous control from 100% to 25%
Economizer ✅ Built-in connection, increases cooling capacity by ~30% at low-temperature conditions
Full-load COP 3.3~3.8 (about 20% higher than comparable units)
Noise ≤58dB (six-cylinder symmetrical design, vibration ≤0.05mm)
Intelligent module IQ module, automatically adjusts internal volume ratio Vi, further improves annual efficiency by 10%
Screw vs. Reciprocating (How to Choose for Pharmaceutical Cold Rooms)
Comparison Item Reciprocating (ECOLINE/4J) Screw (CSH/HSK)
Applicable area <300㎡ >300㎡
Part-load efficiency Significant drop after unloading to 50% Continuous control, remains efficient at part load
Continuous operation Limited (start/stop frequency constraints) 24h continuous operation without issue
Vibration / noise Higher Much lower, GSP validation friendly
Initial investment Low 30%~50% higher
Annual operating electricity cost Higher Save 15%~25%
GSP validation Compliant Compliant, simpler sensor placement
Conclusion:
<150㎡ → Reciprocating compressor (the ECOLINE you asked about earlier is a great fit)
150~500㎡ → Reciprocating still works, but screw is more energy-efficient
>500㎡ → Screw compressor is clearly the better choice
Recommended Solutions for Pharmaceutical Cold Rooms
Cold Room Size Recommended Model Reason
50~150㎡ pharmaceutical storage HSK65 / HSK75 (40~60HP) More energy-efficient than reciprocating, similar footprint
150~300㎡ pharmaceutical storage CSH75 (60~80HP) + economizer Stable continuous operation, simple GSP validation
Vaccine storage (requires 2 independent rooms) 2×HSK85 or 2×CSH85 Meets the "2 or more independent cold rooms" requirement
New green cold room R744 screw compressor (MT series) Zero GWP, 15% higher efficiency, 2030 policy trend
Maintenance Red Lines (Same as Reciprocating Compressors)
Item Requirement
Refrigeration oil Screw compressors are more sensitive to oil quality; must use Bitzer-specified oil, oil change interval ≤4000h
Oil return Oil separator efficiency >99%, oil level difference <15mm
Discharge temperature Not exceeding 105℃ (protected by IQ module)
First start-up Crankcase heater must be preheated for ≥12h
What is the size of your cold room and which refrigerant do you use? We can specify the exact model.
