Operating Room Air Distribution Solutions Dennis Sikkema Director of Technical Sales and Training COPYRIGHT MATERIALS
This presentation is protected by US and International copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. Price Industries, Inc., 2017. Operating Room Solutions Table of Contents
1. Air Distribution Introduction 2. Operating Room Air Distribution – Types, Standards and Research 3. Sizing Examples and Opportunities 4. Ceilings 5. Wrap up/ Questions Operating Room Solutions Air Distribution Introduction Operating Room Solutions Air Distribution Introduction
• Considerations for Air Distribution Products – Airborne Contamination Control – Cleanability – Comfort • Air Distribution strategies – Turbulent/Mixing Flow – Laminar Flow – Radial Flow – Displacement Ventilation Operating Room Solutions Air Distribution Introduction
• Group A – Mounted in or near the ceiling projecting air horizontally • Square plaques • Double deflection grilles (sidewall mount) • Group B – Mounted in the floor with a vertical, non-spreading jet • Linear bar grilles (floor mounted) • Group C – Mounted in the floor with a vertical, spreading jet • Underfloor twist diffuser
Operating Room Solutions Air Distribution Introduction
• Group D – Mounted in or near the floor that project the air horizontally • Displacement diffusers
Operating Room Solutions Air Distribution Introduction
• Group E – Ceiling mounted vertical projection diffuser • Vertical slot diffuser • Air curtain slot diffusers Operating Room Solutions Air Distribution Introduction
• Group E – Non-aspirating – Laminar Flow Diffuser • Unidirectional • Uniform • Low velocity • Low turbulence • Minimal entrainment • Displaces contaminants Operating Room Solutions Operating Room Air Distribution Types, Standards and Research Operating Room Solutions Applicable Standards
ASHRAE 170 • Ventilation of Health Care Facilities (2008) • First released in 2008 • Updated in 2013 • Widely adopted in North America
Facility Guidelines Institute (FGI) • Guidelines for Design and Construction of Health Care Facilities (2010) • Supersedes AIA/FGI 2006 Guidelines • Adopted ASHRAE 170 for all HVAC requirements Operating Room Solutions Air Distribution Introduction Operating Room Solutions Operating Rooms
• Two main systems – Laminar Flow – Air Curtain Operating Room Solutions Operating Rooms
• ASHRAE 170 Requirements
Operating Room Solutions Research
• “Comparison of Operating Room Ventilation Systems in the Protection of the Surgical Site” F. Memarzadeh, A. Manning, 2002 Operating Room Solutions Research
• New considerations – Non-isothermal conditions – Thermal plumes from room occupants Operating Room Solutions Research
• Study findings – Laminar systems most effective – Air curtain systems not considered – Low-level returns most practical – Air change rates less significant than ventilation system design on protection of the surgical site Operating Room Solutions Operating Rooms
• Laminar Flow Systems – Laminar diffuser array concentrated above surgical zone • 70% requirement coverage – Displace particulates to low-level returns
Operating Room Solutions Operating Rooms
• Laminar Flow Systems
Operating Room Solutions Operating Room Systems
• Laminar Flow Diffusers – Performance Guidelines • 25 to 35 cfm/ft2 discharge (ASHRAE 170 – 2008) • Size inlet for 500 fpm Operating Room Solutions Operating Room Systems
• Laminar Flow Diffusers – Internal Baffle Design • Internal Equalization Baffle required for uniform face velocity – Divides plenum into upper and lower “chambers” • Design has significant impact on – Sound and pressure drop » Target HVAC background sound for operating rooms – 35 NC (2011 ASHRAE Handbook – Applications) – Clean-ability » Baffle should be removable to allow for internal cleaning (ASHRAE 170 – 2008 requirement for class B and C operating rooms)
Operating Room Solutions Operating Rooms
• Benefits of Laminar Flow Design – Widely accepted design, ASHRAE 170 requirement – Supporting research – Optional integrated filters – Large footprint ideal for movable OR tables
Operating Room Solutions Operating Rooms
• Challenges of Laminar Flow Design – Diffusers consume valuable ceiling space – Tapering effect – Potential for entrainment of room air at higher ΔT Operating Room Solutions Research
• Air Curtain Study
Operating Room Solutions Research
• Air Curtain Study – J. Swift, E. Avis, B. Millard, T.M. Lawrence. “Air Distribution Strategy Impact on Operating Room Infection Control.” 2007
Operating Room Solutions Research
• Air Curtain Study – J. Swift, E. Avis, B. Millard, T.M. Lawrence. “Air Distribution Strategy Impact on Operating Room Infection Control.” 2007
Operating Room Solutions Research
Laminar System
Air Curtain System
Operating Room Solutions Research
• Study findings – Air curtain improves performance of laminar system – Effective air change rate inside “clean zone” > 50 ach – Tight linear diffuser spacing • Avoid stagnant areas • Prevent induction of “less clean air” Operating Room Solutions Research - Laminar Flow
Acceleration • Tapering column of supply air Operating Room Solutions Research - Air Curtain Operating Room Solutions Research - ASHRAE RP-1397 Operating Room Solutions Research - ASHRAE RP-1397 Operating Room Solutions Research - ASHRAE RP-1397
Operating Room Solutions Research - ASHRAE RP-1397
Acceleration • Result of ΔT between supply and room air • Archimedes principle Operating Room Solutions Operating Rooms
• Air Curtain Systems – Smaller laminar array – Perimeter slot diffusers at 25 to 45 cfm/ft – Displace particulates to low-level returns
Operating Room Solutions Operating Rooms
• Air Curtain System Operating Room Solutions Air Curtain Systems
• Air Curtain Advantages • Free up ceiling space • Better control of air velocity over the surgical table • Barrier between surgical zone and “old” air in room perimeter • Less particle shedding • Match thermal plume • Protects wound site
Operating Room Solutions Operating Room Air Distribution Sizing Examples and Opportunities Operating Room Solutions Operating Rooms
• System Sizing Example: – 480 ft2 Operating Room – 10ft ceiling – 20 ACH = 1600cfm
Operating Room Solutions Operating Rooms
• Perimeter Air Curtain: – 12” offset from surgical table – Laminar flow diffusers only in “Primary supply diffuser array area”
Operating Room Solutions Operating Rooms
– Maximum of 30% non- diffuser equipment – 25 to 35 cfm/ft2 – (x3) 24”x48” laminar diffusers at 25 cfm/ft2 = 600cfm
Operating Room Solutions Operating Rooms
– Inside perimeter of air curtain diffusers: • 2ft offset from primary diffuser array area • 3ft offset from surgical table Operating Room Solutions Operating Rooms
– Active linear slot = 40ft – Air curtain flow (min.) • 1600cfm – 600cfm = 1000cfm • 1000cfm/40ft = 25 cfm/ft • Recommend 25-45 cfm/ft Operating Room Solutions Operating Rooms
• Laminar System Sizing Example – 480 ft2 room – 10ft ceiling – 20 ACH = 1600cfm – Maximum of 30% non- diffuser equipment – 25 to 35 cfm/ft2 – (x6) 24”x48” laminar diffusers at 33 cfm/ft2 = 1600cfm
Operating Room Solutions Operating Rooms
• 480 ft2 at 20 ACH = 1600 cfm
Operating Room Solutions Operating Rooms
• 600 ft2 at 20 ACH = 2000 cfm
Operating Room Solutions Operating Rooms
• 600 ft2 at 25 ACH = 2500 cfm
Operating Room Solutions Spot the Opportunities
• Identify system improvement opportunities
Operating Room Solutions Spot the Opportunities
• Large gaps at corners of perimeter air curtain diffuser • 12 ft2 of laminar flow diffuser coverage above surgical table unlikely to meet ASHRAE 170 requirements
Operating Room Solutions Spot the Opportunities
• Identify system improvement opportunities
Operating Room Solutions Spot the Opportunities
• Gaps in perimeter air curtain diffuser • Increase airflow through laminar flow diffusers – ASHRAE 170 recommends 25 cfm/ft2 minimum for laminar flow diffusers
Operating Room Solutions Spot the Opportunities
• Identify system improvement opportunities
Operating Room Solutions Spot the Opportunities
• No laminar flow diffusers • Perimeter air curtain too close to walls • Multiple gaps in perimeter air curtain
Operating Room Solutions Spot the Opportunities
• Identify system improvement opportunities
Operating Room Solutions Spot the Opportunities
• Unusual laminar flow diffuser coverage • Unlikely to satisfy ASHRAE 170 requirements for laminar flow diffuser coverage Operating Room Solutions Ceiling Systems Operating Room Solutions Ceiling Systems
Challenges:
Congested Ceilings: • More and more equipment installed in ceiling
Tight construction deadlines: • Desire to reduce construction time, downtime of OR
Access above ceiling: • Required to access to equipment in ceiling plenum
Operating Room Solutions Ceiling Systems
Welded Systems • Fully customizable ceiling grid • Support lighting, HVAC and other equipment
Operating Room Solutions Ceiling Systems
• TIG welded modules, up to 4’x10’ sections
Operating Room Solutions Ceiling Systems
• Extruded Aluminum – 1/8” thick • Heavy Duty rating – ASTM C635
Operating Room Solutions Ceiling Systems
• No structural steel required • Threaded rod or hanger wire every 48”
Operating Room Solutions Ceiling Systems
• Quick installation time (few modules) • 12’x16’ ceiling = 9 modules
Operating Room Solutions Ceiling Systems
Ceiling Panels: • Various styles, custom sizes
Operating Room Solutions Ceiling Systems
• Various finishes available
Brushed Aluminum
White Powder Coat
Clear Anodized Operating Room Solutions Ceiling Systems
Integrated Unistrut® • Facilitates mounting of C-Arm support tracks • Cath. Labs and Hybrid operating rooms
Operating Room Solutions Ceiling Systems
• Customized grid sizes to match any layout • Closure strip for sealing, cleaning and aesthetics
Operating Room Solutions Ceiling Systems
• Growing Demand for Integrated Plenum Systems – Bigger O.R. spaces / more diffusers – Additional equipment / congested ceiling plenums – Greater emphasis on installation time/cost
Operating Room Solutions Ceiling Systems
Integrated Plenum Systems • Inlet connections on common plenum • Reduce inlets • Low profile – 12” tall
Operating Room Solutions Ceiling Systems
• Ceiling, diffuser and plenum fully integrated, maximize perforated area • Flush face assembly
Operating Room Solutions Ceiling Systems
• Fully customizable, job specific submittals • Integrate w/ booms, pendants and med gas • No structural steel required • Threaded rod or hanger wire at each corner of module
Operating Room Solutions Integrated Plenum Systems Operating Room Solutions Integrated Plenum Systems Operating Room Solutions Integrated Plenum Systems Operating Room Solutions Table of Contents
1. Air Distribution Introduction 2. Operating Room Air Distribution – Types, Standards and Research 3. Sizing Examples and Opportunities 4. Ceilings 5. Wrap up/ Questions Operating Room Solutions Questions