two scientists looking at a microscope

Without the proper clean room ventilation system, your controlled environment becomes contaminated. How can you improve your clean room’s HVAC?

HVAC Systems for Your Clean Room Design

To run efficiently, your clean room must have low levels of:

  • Pollution
  • Dust and debris
  • Microbes
  • Aerosol particles
  • Chemical vapors

It must also meet the following clean room classifications:

  • Federal Standard 209e
  • ISO 14644-1
  • ICH Q7A

Clean room designs require knowledge of regulations, cleanliness levels, airflow, temperature control, room pressurization, humidity levels, and activities in the clean room. 

How can you ensure your clean room ventilation system meets the proper standards and keeps out harmful germs and chemicals? 

These systems require special attention to the following:

Air Supply and Air Flow Patterns

When creating your clean room HVAC design, consider your space’s air supply and air flow patterns.

Your air change per hour, or air change rate, is based on the amount and kinds of activity taking place in your clean room.

A quality clean room ventilation system ensures your air supply is clean, your air flow is consistent, and your HVAC is designed specifically for the size and traffic of your clean room.

Highly Efficient Clean Room Filters

To reach the correct air change rate, you must change your HEPA filters a certain amount of times per hour. Your air changes per hour (ACH) rate depends on the classification of your clean room:

  • ISO 5: 240 to 360 ACH
  • ISO 6: 90 to 180 ACH
  • ISO 7: 30 to 60 ACH
  • ISO 8: 10 to 25 ACH

These rates are subject to change, and based on the size of your room, number of people, and equipment, your HVAC clean room expert will decide which ACH is best.

Clean Room Pressure Balancing

Pressurization in your clean room determines the room’s air leakage. 

Positive pressure means the air pressure inside the room is greater than the pressure outside and pumps clean air into the room. You use positive pressure when the priority of the clean room is keeping out any possible contaminants. 

In the event of an air leak in a positive pressure space, pressure forces clean air out of the clean room rather than leaving unfiltered air in the room.

In a negative pressure clean room, the air pressure in the room is lower than the pressure outside and filters air out of the room. The goal of negative pressure rooms is to keep contamination from escaping the clean room.

Any air leaks in a negative pressure environment flow out of a filter, so no contaminants enter the outside air. The air pressure your clean room needs is dependent on your industry:


Negative Air Pressure Positive Air Pressure
Pharmaceutical product manufacturing Microelectronics
Biochemical testing Aerospace
Medical industry (research, quarantine) Military and defense applications


Pressure balancing is essential to your clean room design and HVAC system.

What Equipment Do I Need for My Clean Room Ventilation System?

You need several pieces of equipment to ventilate your clean room properly:

Air Filters

Air filters are made of:

  • Filter media
  • A frame
  • Sealant
  • A faceguard or gasket

These filters are one of the most important pieces of a clean room, as they keep out debris, contaminants, and toxins.

Pressure Airlock

Airlocks prevent cross contamination and protect the clean room from adjacent areas. There are three types of airlocks:

  1. Cascading pressure airlock: Pushes clean air from the clean room into adjacent areas
  2. Pressure bubble airlock: Pushes air out and into both protected areas and creates a barrier between the two spaces
  3. Pressure sink airlock: Pulls air in from both areas it’s protecting to create a barrier

Sanitary Cooler/Chiller and Heater

Your cooler/chiller and heater needs to meet ISO standards for your clean room. Cooling and heating equipment must lower the temperature of your clean room without contaminating it.

Where Can I Get Help With My Clean Room Ventilation System?

Whether you need an entirely new clean room HVAC system or want to enhance your existing system, React Industries is the place for you. Our clean room ventilation systems meet FDA requirements and are completely customizable based on the size of your space.

Contact us today to improve your controlled environment’s HVAC system.