Views: 0 Author: Site Editor Publish Time: 2026-10-22 Origin: Site
At CSTHEATEXCHANGER, we design and manufacture custom-engineered hygienic air conditioning units (Hygienic Air Handling Units / Cleanroom AHUs) engineered specifically for hospital operating rooms, surgical suites, intensive care units (ICU), and medical cleanrooms. Surgical environments demand absolute sterility, positive pressure containment, unidirectional laminar airflow, and tight psychrometric climate control (18°C–24°C and 45%–55% relative humidity). CSTHEATEXCHANGER medical air conditioning units feature thermal bridge-free double-skin casings (EN 1886 Class TB1/T2), three-stage HEPA filtration (H13/H14), stainless steel sloped drain pans with zero water stagnation, and zero-cross-contamination run-around heat recovery loops, fully complying with international healthcare standards including DIN 1946-4, ISO 14644-1 (Class 5/7), HTM 03-01, and ASHRAE 170.
A hospital medical operating room is among the most demanding indoor environments in building services engineering. During surgical procedures, open incisions expose patients directly to ambient air, where airborne microorganisms, shed skin particles, and dust carry severe Surgical Site Infection (SSI) risks.
Supplying conditioned air to surgical suites requires addressing multiple critical parameters simultaneously:
Ultra-Clean Air Sterility (ISO Class 5 & Class 7): Operating rooms require continuous laminar displacement airflow (air change rates of 20 to 30+ ACH) to sweep airborne bacteria and anesthesia gases away from the surgical table toward low-level exhaust grilles.
Precision Temperature Control (18°C to 24°C): Surgeons performing complex orthopedic or cardiac procedures wearing multi-layer sterile gowns require cool room temperatures (down to 18°C) to prevent perspiration, while pediatric or burn surgeries require warmer conditions (22°C–24°C) to prevent patient hypothermia.
Strict Relative Humidity Band (45% to 55% RH): Relative humidity must remain strictly between 45% and 55% RH. Air falling below 40% RH induces electrostatic discharge risks that can damage sensitive surgical electronics and dry exposed patient tissue. Air rising above 60% RH fosters rapid microbial spore germination and compromises sterile surgical drape integrity.
Positive Pressure Containment (+10 Pa to +25 Pa): The operating room must maintain continuous positive air pressure relative to surrounding corridors, dirty utility rooms, and scrub areas to prevent the infiltration of unsterile air when doors open.
Zero Microbial Growth Inside the AHU: The air handling unit itself must not become a microbial reservoir. Eliminating porous insulation materials, dead air zones, standing drain water, and belt-driven dust generation is vital.
At CSTHEATEXCHANGER, we engineer every medical operating room air handling unit according to strict hygienic guidelines (DIN 1946-4 and VDI 6022):
CSTHEATEXCHANGER® HYGIENIC OPERATING ROOM AHU ARCHITECTURE
┌────────────────────────────────────────────────────────────────────────┐
│ 100% Fresh Air / Return Air Intake with Multi-Blade Air-Tight Dampers │
├────────────────────────────────────────────────────────────────────────┤
│ ◄◄◄ Stage 1 Pre-Filter (G4 / MERV 8) + Stage 2 Secondary (F9 / MERV 14) │
├────────────────────────────────────────────────────────────────────────┤
│ Run-Around Coil Heat Recovery (100% Fluid-Isolated Exhaust Air Loop) │
├────────────────────────────────────────────────────────────────────────┤
│ Deep Chilled Water / DX Dehumidification Cooling Coil │
│ (Hydrophilic Coated Aluminum Fins / Fully Drainable Stainless Header) │
├────────────────────────────────────────────────────────────────────────┤
│ Sloped SS304/SS316 Drain Pan (Zero Water Pooling · Antimicrobial P-Trap)│
├────────────────────────────────────────────────────────────────────────┤
│ Precision Stainless Steel Reheat Coil (Hot Water / Electric Element) │
├────────────────────────────────────────────────────────────────────────┤
│ Direct-Drive EC Plug Fan (Zero Belt Dust · Inverter Speed Modulation) │
├────────────────────────────────────────────────────────────────────────┤
│ Terminal Supply Air to Ceiling HEPA Filter Canopy (H14: 99.995% @ 0.3μm)│
└──────────────────────────────────┬─────────────────────────────────────┘
│
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Unidirectional Laminar Clean Airflow over Surgical Table
(ISO Class 5 Sterility · Precise 18°C - 24°C · 45% - 55% RH)CSTHEATEXCHANGER medical AHU enclosures are fabricated with 50 mm thick double-skin sandwich panels filled with high-density polyurethane or non-combustible rockwool insulation. Frameless structural composite breaks eliminate thermal bridging, preventing exterior condensation sweating. The interior casing features completely smooth, non-porous stainless steel (SS304) or antibacterial powder-coated surfaces with coved corners that facilitate seamless disinfectant wipe-downs.
Pre-Filtration (ISO ePM10 50% / G4): Captures coarse outdoor particulates and insects.
Secondary Fine Filtration (ISO ePM1 80% / F9): Removes fine atmospheric dust and pollen before reaching cooling coils.
Terminal HEPA Filter (EN 1822 H13/H14): Installed at the AHU discharge or operating room laminar flow ceiling canopy, achieving 99.995% particle capture efficiency at 0.3 microns to eliminate all bacteria, fungal spores, and viral droplets.
To maintain exact 45%–55% RH during humid summer conditions, CSTHEATEXCHANGER deep-row cooling coils chill incoming air down to its dew point (10°C–12°C) to condense out moisture. Air then passes immediately across our precision stainless steel reheat coil (supplied by hot water or electric modulation) to bring supply air up to the exact target surgical delivery temperature (18°C–21°C).
Drain pans are fabricated from heavy-gauge AISI 304 or 316L stainless steel, sloped in all directions toward a central deep-seal drain port. This design guarantees immediate, complete condensate runoff with zero standing water pools where Pseudomonas or Legionella biofilm colonies could develop.
Traditional belt-driven fans release rubber particulate dust as belts wear, contaminating cleanroom air streams. CSTHEATEXCHANGER utilizes direct-drive, backward-curved EC plug fans. With no belts, pulleys, or oil lubricants, these fans generate zero particulate emissions and allow precision variable-speed pressure control via BMS.
To comply with medical codes requiring 100% fresh air without cross-contaminating supply air with infectious exhaust air, CSTHEATEXCHANGER integrates closed-circuit run-around coil heat recovery systems. Glycol circulating between separate exhaust and supply coils transfers sensible energy with 100% physical air stream isolation.
Ultra-Clean Laminar Flow Operating Rooms (Class I / ISO 5): Orthopedic implant surgery, open-heart surgery, neurosurgery, and organ transplant suites.
Standard Turbulent Flow Operating Rooms (Class II / ISO 7): General surgery, laparoscopy, endoscopy, and emergency trauma rooms.
Hybrid Operating Theatres & Cath Labs: Surgical rooms integrating large medical imaging equipment (CT, MRI, C-Arms) requiring high-capacity sensible heat extraction.
Isolation Suites & Intensive Care Units (ICU): Negative-pressure airborne infection isolation rooms (AIIR) and positive-pressure protective environment (PE) suites.
Pharmaceutical Cleanrooms & Hospital Compounding Pharmacies: Sterile drug preparation and aseptic cleanroom environments.
Airflow Capacity Range: 2,000 m³/h to 40,000 m³/h per hygienic unit.
External Static Pressure: 500 Pa to 1,800 Pa (Overcoming high-resistance HEPA filter banks and duct runs).
Casing Mechanical Performance (EN 1886): Thermal Transmittance: T2; Thermal Bridging: TB1; Casing Air Leakage: Class L1; Deflection: Class D1.
Internal Casing Materials: AISI 304 / AISI 316L Stainless Steel or Antimicrobial Powder-Coated Steel.
Cooling & Heating Mediums: Chilled Water, Direct Expansion (DX) R410A/R32/R454B, Hot Water, Steam, or Electric Heaters.
Standards Compliance: Fully compliant with DIN 1946-4, VDI 6022, VDI 3803, ISO 14644-1, HTM 03-01, and ASHRAE Standard 170.
Rotary thermal wheels carry a 2% to 5% air leakage rate between exhaust and supply air streams, which can transfer infectious pathogens or anesthesia gases back into sterile rooms. CSTHEATEXCHANGER run-around coil systems utilize completely separated fluid loops with zero physical air crossover, guaranteeing 100% cross-contamination safety.
Our integrated PLC controller continuously measures operating room differential pressure sensors and modulates the variable-speed supply and exhaust EC plug fans, maintaining a steady +15 Pa positive pressure barrier even when room doors are opened and closed.
Yes. CSTHEATEXCHANGER provides fully integrated operating theatre packages, including the hygienic AHU, duct-mounted sound attenuators, terminal HEPA filter laminar flow ceiling canopies, and localized surgical control panels.
Contact CSTHEATEXCHANGER today with your hospital project parameters:
Operating Room Classification: ISO Class 5 (Laminar Flow) or ISO Class 7 (Turbulent Flow)
Room Dimensions (Length × Width × Height) & Target Air Change Rate (ACH)
Design Temperature (18°C–24°C) & Relative Humidity (45%–55% RH) Targets
Fresh Air Ratio: 100% Outdoor Air (Once-Through) or Recirculation Mode
Cooling / Heating Utility Available: Chilled Water, DX Refrigerant, Hot Water, or Electric
Our healthcare thermal engineering team will provide detailed psychrometric analysis, air filtration selection datasheets, 3D CAD dimensional drawings, and factory-direct proposals.
Website: https://www.cstheatexchanger.com/
Technical Inquiries: info@cstheatexchanger.com
