HEPA Filters for Operating Rooms and Surgical Environments

Clean-Link supplies HEPA filters for operating rooms, surgical suites, operating theatres, hospital HVAC systems, terminal filter housings and controlled healthcare ventilation projects.

Operating-room filtration should be selected as part of the complete ventilation system—not by filter efficiency alone. Filter dimensions, rated airflow, pressure drop, terminal housing design, sealing method, airflow distribution, prefiltration and project-specific healthcare requirements all affect final system performance.

Clean-Link can support H13 and H14 project requirements, mini-pleat HEPA filters, terminal HEPA configurations, gasket and gel seals, custom dimensions, airflow and pressure-drop review, replacement filter matching and OEM supply.

Planning a new project or replacing an existing OR HEPA filter?
Start with Filter Size + Efficiency + Airflow + Housing/Terminal Type + Existing Filter Photo.

Request Technical Support →

Does Every Operating Room Require a HEPA Filter?

Not necessarily.

This is an important distinction when specifying HEPA filters for operating rooms.

Healthcare ventilation requirements depend on:

• Type of surgical space
• Procedure category
• Patient risk
• Airflow design
• Local codes
• Hospital engineering requirements
• Applicable edition of healthcare ventilation standards

ASHRAE currently lists ANSI/ASHRAE/ASHE Standard 170-2025 — Ventilation of Health Care Facilities as the current edition. The standard addresses ventilation requirements including pressure relationships, ventilation rates and filtration requirements for healthcare spaces.

Publicly available ASHRAE material based on the 2021 edition showed MERV 16 as the filtration level for a general operating room, while HEPA filtration is used in certain higher-risk healthcare environments and surgical applications.

For this reason:

HEPA filtration should be specified according to the actual operating-room design and project requirements—not assumed to be mandatory for every OR.

Where Are HEPA Filters Used in Operating-Room Ventilation?

When HEPA filtration is specified, it may be installed at different points in the system.

Common configurations include:

Terminal HEPA Filters

HEPA filters installed close to or directly at the supply-air outlet can provide final filtration immediately before conditioned air enters the operating room.

Typical configurations include:

• Ceiling HEPA modules
• Terminal HEPA housings
• Laminar / unidirectional airflow ceilings
• Filter fan units in selected designs
• Custom ceiling filter assemblies

Terminal filtration minimizes the amount of downstream ductwork between the final filter and the room.

HEPA Filters in Air Handling Units

Some systems use HEPA filtration in centralized air-handling or recirculation systems.

Important considerations include:

• Available fan static pressure
• Filter bank dimensions
• Prefiltration
• Seal integrity
• Airflow
• Pressure drop
• Filter access
• Maintenance strategy

HEPA Filtration for Recirculated Air

Healthcare ventilation requirements can differ where air is recirculated rather than exhausted.

CDC guidance notes that, in certain healthcare applications, recirculated air can be passed through HEPA filtration before being returned to other spaces.

Actual operating-room configuration should always follow the applicable healthcare engineering requirements.

Terminal HEPA Filters for Operating Rooms

Terminal HEPA filters are one of the most relevant product types for critical operating-room projects.

They are installed near the final supply point, often within a ceiling terminal housing or airflow ceiling system.

Clean-Link can support terminal filters with:

• H13 / H14 project requirements
• Mini-pleat construction
• Aluminum frames
• Custom dimensions
• Gel seal
• Gasket seal
• Protective grille options
• Rated airflow review
• Pressure drop review
• Drawing-based manufacturing

The correct filter depends on the terminal housing and airflow design.

A terminal HEPA filter should not be selected from nominal dimensions alone.

Related collection: Mini-Pleat HEPA Filters →

HEPA Filters for Laminar and Unidirectional Airflow Ceilings

Some operating rooms use unidirectional or laminar airflow systems designed to deliver controlled filtered air over the surgical zone.

The final HEPA filters can form part of a larger ceiling system that distributes air over:

• Surgical table
• Sterile field
• Surgical team
• Instrument area

The HEPA filter is only one component of this airflow system.

Overall performance also depends on:

• Ceiling coverage
• Supply-air volume
• Air velocity
• Room geometry
• Return-air location
• Heat loads
• Surgical lights and equipment
• Staff movement
• Room pressure

ISO 14644-3 distinguishes between testing approaches for unidirectional and non-unidirectional clean-air environments, reinforcing the point that airflow pattern matters alongside particle filtration.

H13 and H14 HEPA Filters for Operating Rooms

Clean-Link can support H13 and H14 project requirements where these efficiency classes are specified.

However, the highest efficiency is not automatically the best selection.

The filter should also match:

• Required airflow
• Pressure drop limit
• Fan capability
• Terminal size
• Filter media area
• Room airflow strategy
• Housing configuration
• Integrity testing requirement

For HEPA filter classification and performance testing, ISO 29463 provides the international high-efficiency filter framework.

Related guide: Understanding HEPA Filter Efficiency →

Mini-Pleat HEPA Filters for Surgical Ceiling Systems

Mini-pleat construction is commonly suitable for terminal healthcare filtration because a large media area can be packaged within a relatively compact depth.

This can help balance:

• HEPA efficiency
• Airflow
• Media area
• Pressure drop
• Ceiling installation depth
• Filter weight

But mini-pleat does not automatically mean low pressure drop.

Actual resistance depends on:

• Media type
• Pleat geometry
• Total media area
• Filter dimensions
• Efficiency class
• Airflow
• Face velocity

For project selection, rated airflow and initial pressure drop should be reviewed together.

Gel-Seal HEPA Filters for Operating-Room Ceiling Housings

Some terminal HEPA systems use a gel-filled channel in the filter frame together with a compatible knife-edge housing.

This arrangement creates the filter-to-housing sealing interface.

Gel-seal HEPA filters can be useful in terminal installations where:

• The existing ceiling housing uses a knife edge
• Filter replacement must match an existing gel channel
• Housing-to-filter bypass must be carefully controlled
• Clean terminal installation is required

Important matching parameters include:

• Filter dimensions
• Gel-channel width
• Gel-channel depth
• Gel-channel position
• Knife-edge location
• Filter orientation
• Rated airflow

A gel seal should be selected because it matches the housing design—not simply because it appears to be a “higher-grade” sealing method.

Related collection: Gel-Seal HEPA Filters →

Gasket-Seal HEPA Filters

Other hospital HVAC and terminal systems may use conventional gasketed HEPA filters.

Possible configurations include:

• Upstream gasket
• Downstream gasket
• Full-face gasket
• Custom gasket location

Gasket performance depends on:

• Compression
• Housing flatness
• Frame alignment
• Seal material
• Installation quality

ASHRAE healthcare guidance specifically notes the importance of filter seals and gaskets, because bypass around the filter can significantly reduce installed filtration performance.

Related guide: Air Filter Bypass Leakage →

Airflow and Pressure Drop Matter as Much as Filter Size

One of the most common replacement mistakes is matching only:

Length × Width × Depth

Two HEPA filters with identical external dimensions can still have different:

• Media area
• Rated airflow
• Initial pressure drop
• Efficiency
• Pleat configuration
• Frame structure

A filter with substantially higher resistance can affect system airflow.

A filter with different airflow characteristics can also change how the terminal system performs.

For operating-room projects, review:

Related guide: Air Filter Pressure Drop →

Positive Pressure and Operating-Room Airflow

The filtration system works together with the room pressure and ventilation strategy.

Operating rooms are commonly designed to maintain positive pressure relative to surrounding areas so that airflow tends to move outward rather than allowing uncontrolled air to enter from adjacent spaces.

CDC healthcare ventilation guidance specifically recommends positive-pressure ventilation for operating rooms.

HEPA filtration alone cannot create or maintain this pressure relationship.

Room pressure also depends on:

• Supply-air volume
• Return / exhaust airflow
• Door operation
• Leakage
• HVAC balancing
• Room envelope
• Adjacent spaces

This is why:

Operating-room air cleanliness is a system property—not a filter-only property.

HEPA Filter Integrity and Leakage Testing

Efficiency rating and installed integrity are not the same thing.

A filter may use high-efficiency media, but performance can still be affected by:

• Media damage
• Pack-to-frame leakage
• Damaged gasket
• Gel-seal problems
• Incorrect installation
• Housing leakage
• Poor frame compression

Depending on the healthcare project, requirements may include:

• Factory filter testing
• Individual test documentation
• Resistance data
• Leakage / scan testing
• Installed filter integrity verification
• Airflow verification
• Room commissioning

Camfil strongly emphasizes individual HEPA testing and certificates of conformance in its healthcare filtration guidance, which reflects the importance of traceable test information in critical healthcare applications.

Clean-Link can discuss filter-level testing and documentation according to the confirmed project specification.

HEPA Filters Are Only One Part of Operating-Room Air Quality

An HEPA filter should not be presented as a standalone infection-control solution.

Operating-room environmental performance also depends on:

• Ventilation rate
• Air distribution
• Room pressure
• Temperature
• Humidity
• Room integrity
• Equipment
• Personnel movement
• Door opening
• Cleaning and operating procedures

CDC explicitly treats operating-room filtration as part of a broader environmental ventilation strategy rather than as a standalone measure.

This is an important reason to avoid claims such as:

• “Prevents surgical infections”
• “Creates a sterile operating room”
• “Eliminates pathogens”
• “Guarantees contamination control”

More accurate language is:

HEPA filtration can support airborne particle control when correctly integrated into the operating-room ventilation system.

Prefiltration Before Operating-Room HEPA Filters

HEPA filters are normally expensive final-stage filters.

Using suitable upstream filtration can help reduce loading from larger particles before the air reaches the HEPA stage.

A healthcare filtration system may therefore use staged filtration such as:

Prefilter → Fine Filter → HEPA Final Filter

Benefits can include:

• Reduced HEPA dust loading
• Slower pressure-drop increase
• Longer practical HEPA service intervals
• Better protection of terminal filters
• More predictable maintenance

Camfil also recommends an intermediate high-efficiency stage ahead of HEPA filtration in critical healthcare applications to help increase HEPA filter life.

Related: Pocket Filters →

             Compact & V-Bank Filters →

Replacement HEPA Filters for Existing Operating Rooms

Operating-room replacement projects are one of the strongest commercial opportunities for this page.

A replacement HEPA filter should be matched by more than brand or nominal size.

Confirm:

Minimum Information to Start

Filter Photo + Actual Dimensions + Filter Location + Hospital Application

For gel-seal terminal filters, also send:

Housing Photo + Gel Channel / Knife-Edge Information

Custom HEPA Filters for Operating-Room Projects

Not every surgical ceiling or hospital HVAC project uses standard filter dimensions.

Clean-Link can support custom HEPA filter requirements including:

• Length
• Width
• Depth
• H13 / H14
• Mini-pleat construction
• Aluminum frame
• Galvanized frame
• Gasket configuration
• Gel seal
• Protective grille
• Rated airflow
• Pressure drop target
• Drawing matching
• Existing sample matching
• OEM packaging

Related page: Custom HEPA Filters →

New Surgical Suite and HVAC Projects

For new operating-room projects, filter selection should ideally begin before the terminal housing or HVAC filter bank is finalized.

Useful project information includes:

• Number and type of operating rooms
• Required filtration level
• Terminal or AHU installation
• Ceiling system design
• Filter dimensions
• Airflow per terminal
• Total airflow
• Pressure drop allowance
• Frame and seal requirements
• Local healthcare ventilation standard
• Testing requirements
• Replacement access
• Project quantity

Clean-Link can review these filter parameters with HVAC contractors, hospital engineering teams, distributors and equipment manufacturers.

Common Operating-Room HEPA Filter Applications

HEPA filtration may be specified for selected applications such as:

• Orthopedic operating rooms
• Transplant surgical suites
• Neurosurgical environments
• Burn-unit surgical areas
• High-risk operating rooms
• Unidirectional airflow operating theatres
• Surgical clean-air ceiling systems
• Hospital terminal filtration
• Selected hybrid operating rooms
• Hospital HVAC final filtration
• OEM surgical ventilation equipment

The actual requirement must be confirmed from the project specification.

Standard and Regulatory Context

ANSI/ASHRAE/ASHE Standard 170

ANSI/ASHRAE/ASHE Standard 170 is a primary healthcare ventilation standard in North America. ASHRAE lists the 2025 edition as current and describes it as providing ventilation requirements for healthcare facilities.

Operating-room filtration requirements should be checked against the edition adopted by the project's jurisdiction.

ISO 29463

ISO 29463 provides classification and test methods for high-efficiency filters.

It is relevant when specifying H13/H14 or other high-efficiency filter performance and test requirements.

ISO 14644

ISO 14644 is primarily a cleanroom and controlled-environment standards family.

ISO 14644-1 covers classification of airborne particle cleanliness, while ISO 14644-3 provides cleanroom and clean-zone test methods.

Not every operating room should automatically be described as an “ISO cleanroom,” so project-specific requirements should be checked before applying ISO cleanroom terminology.

How to Select an Operating-Room HEPA Filter

Before requesting a quotation, confirm:

1. Application
   Operating room, surgical ceiling, AHU, hospital HVAC, OEM equipment.
2. Filter location
   Terminal supply, central AHU, recirculation, other.
3. Actual dimensions
   Length × width × depth.
4. Efficiency
   H13, H14 or specified project requirement.
5. Rated airflow
   Per filter or terminal module.
6. Pressure drop
   Initial resistance or project limit.
7. Frame construction
   Aluminum, galvanized steel or other.
8. Sealing method
   Gasket, gel seal or housing-specific arrangement.
9. Housing configuration
   Terminal housing, knife edge, box housing, filter bank.
10. Testing requirement
    Efficiency test, scan/leakage test, individual report, project documentation.
11. Existing filter information
    Photo, label, drawing or sample.
12. Quantity
    Initial project quantity and replacement demand.
    

What to Send Clean-Link for Technical Review

For the fastest review, send:

Filter Size + Efficiency + Airflow + Pressure Drop + Seal Type + Filter Location + Existing Filter Photo

For a replacement terminal filter, also send:

• Housing photo
• Gel-channel or gasket information
• Existing filter label
• Installation orientation

For a new surgical-suite project:

• Filter schedule
• HVAC drawing
• Airflow per terminal
• Project standard
• Required quantity

Why Clean-Link for Operating-Room HEPA Filter Projects?

Clean-Link supports B2B high-efficiency filtration projects for:

• Hospital engineering teams
• HVAC contractors
• Cleanroom contractors
• Medical equipment manufacturers
• Air filter distributors
• Facility maintenance providers
• Project procurement teams

Our HEPA filter support can include:

• H13 / H14 project requirements
• Mini-pleat HEPA filters
• Terminal HEPA filters
• Gel-seal configurations
• Gasket-seal configurations
• Custom filter dimensions
• Airflow review
• Pressure-drop review
• Drawing-based manufacturing
• Sample matching
• Testing requirements where applicable
• OEM and repeat supply

The objective is to match the filter to the airflow system, terminal housing and project requirement, rather than simply supplying a filter with the correct outside dimensions.

Request an Operating-Room HEPA Filter Quote

Need an HEPA filter for an operating room, surgical ceiling, hospital HVAC system or replacement project?

Send Clean-Link:

Filter Dimensions + Efficiency + Airflow + Seal Type + Filter Location + Existing Filter Photo

For more complex projects, include:

• Pressure drop requirement
• Terminal drawing
• Housing photo
• Hospital application
• Testing requirement
• Quantity

Request Technical Support →

FAQ

Are HEPA filters required in every operating room?

No. Requirements vary by operating-room type, procedure, ventilation design, jurisdiction and applicable healthcare standard. The current ASHRAE Standard 170 edition should be checked together with local project requirements.

What type of HEPA filter is used in an operating room?

Where HEPA filtration is specified, operating rooms may use terminal mini-pleat HEPA filters, gel-seal filters, gasket-seal filters or HEPA filters installed within AHU/filter-bank systems. The exact construction depends on the HVAC design.

Are H13 and H14 HEPA filters available for surgical applications?

Clean-Link can support H13 and H14 project requirements depending on dimensions, airflow, pressure drop, sealing and testing specifications.

What is a terminal HEPA filter?

A terminal HEPA filter is installed close to the final supply-air outlet, such as within a ceiling terminal housing. This provides final-stage filtration shortly before the supply air enters the controlled space.

Are gel-seal HEPA filters used in operating rooms?

They can be used where compatible knife-edge terminal housings are installed. The gel-channel geometry must match the housing.

Why is pressure drop important?

The filter operates as part of the HVAC airflow system. Excessive resistance can affect available airflow and fan operation, so pressure drop should be checked together with filter efficiency.

Can I replace an operating-room HEPA filter using only the dimensions?

Dimensions alone are not sufficient. Efficiency, airflow, pressure drop, frame, sealing method, terminal housing and testing requirements should also be confirmed.

Can Clean-Link manufacture custom operating-room HEPA filters?

Yes. Custom dimensions, H13/H14 requirements, frame options, gasket or gel seals, airflow and pressure-drop requirements can be reviewed.

Can HEPA filters prevent surgical-site infections?

HEPA filters support airborne particle control, but surgical-site infection risk depends on many clinical, environmental and operational factors. The filter should not be presented as a standalone infection-prevention measure.

How often should an operating-room HEPA filter be replaced?

Replacement should be based on system condition and facility procedures rather than calendar time alone. Differential pressure, airflow performance, filter integrity, maintenance requirements and project procedures should be considered.

What information is needed for a quotation?

Start with the filter dimensions, efficiency, airflow, seal type, installation location, current filter photo and quantity. Pressure-drop data and housing drawings are also useful.