Cleanroom and Hospital Air Conditioning Systems
Pressure cascaded, HEPA filtered systems for operating theatres, intensive care units, laboratories and production cleanrooms.
In these spaces air conditioning is not a matter of comfort but directly a matter of patient and product safety. Temperature, humidity, pressure difference, particle count and air change rate have to be maintained together.
Setting up the pressure cascade correctly is the backbone of cleanroom design. A pressure profile that decreases from the sterile area towards the corridor prevents contaminated air from passing into the clean area. So that this profile is not disturbed when doors open, air flow rates and door tightness are calculated together.
Filtration is built up in stages: coarse filter, fine filter and HEPA at the final stage. The final stage filters are located inside the room at the supply point and are subjected to on-site leak testing.
The measurement and validation reports produced after commissioning are used in the operating licence and accreditation processes of the facility. We prepare these reports as a mandatory part of the handover file.
Kapsam
- Room classification and pressure cascade design
- Hygienic air handling unit selection and installation
- HEPA filter units and laminar flow ceilings
- Stainless steel or hygienic ductwork
- Dehumidification and humidification solutions
- Pressure monitoring, alarm and recording systems
- Air change rate and particle measurement
- Validation measurements and reporting
How we work
Classification
The cleanliness class, pressure direction and air change requirement of each room are defined.
Design
The air handling unit, ductwork, filtration and control architecture are designed.
Installation
The system is built in accordance with hygienic installation rules.
Balancing
Flow rates and pressure differences are measured and set to the design values.
Validation
Particle, leak and airflow tests are carried out and reported.
Periodic verification
The measurements are repeated at defined intervals and recorded.
Common questions
How often should operating theatre ventilation be validated?
Initial validation after installation is mandatory; periodic verification follows. The measurements have to be repeated after a filter change, after alterations inside the room or after any intervention in the system.
When is a HEPA filter replaced?
Not on a time basis, but according to the pressure difference and the result of the leak test. It is replaced when the pressure difference reaches the manufacturer limit or when a leak is detected in testing.
Is a laminar flow ceiling required in every operating theatre?
That depends on the risk class of the theatre. Laminar flow is preferred in rooms used for high risk procedures such as orthopaedic and cardiac surgery. The decision should be made together with the hospital infection control committee.
Can an existing operating theatre be upgraded?
Yes. In most cases the room can be brought up to standard by overhauling the air handling unit, renewing the filter stages and adding pressure control. The existing condition has to be measured first.
