Optimising HVAC Systems for Pharma Cleanrooms: Why Simplicity Wins

Designing HVAC systems for pharma cleanrooms has traditionally been an exercise in adding more: more air changes, more equipment, more control points, and more complexity. But as the pharmaceutical sector matures and energy efficiency, sustainability, and operational reliability become front of mind, a new design philosophy is emerging: simplicity with purpose.

Today, the best engineering solutions are not the most complex; they’re the most thoughtfully optimised. In pharmaceutical cleanrooms, this means HVAC systems that achieve compliance with GMP requirements while avoiding unnecessary layers of machinery, ductwork, automation, and air change rates that provide little added value.

Below, we explore why cleanroom HVAC design benefits from simplification and how right-sized engineering leads to better long-term performance.

Air Change Rates Should Be a Consequence of Design: Not the Starting Point

For years, many cleanroom HVAC designs began with fixed Air Change Rates (ACR) tables. Designers would pick a number, often 40, 50, 60 ACH or more, based on habit rather than science. This “more is better” mindset leads to oversized systems with higher initial capital cost and long-term energy penalties.

Modern regulatory guidance, including EU GMP Annexe 1 and ISO cleanroom standards, emphasises performance, not rigid ACR values. In other words, air change rates should be derived from contamination control needs, not assumed upfront.

A smart design approach uses:

• Process-driven contamination analysis,

• Occupancy levels,

• Equipment heat loads,

• Particle generation rates,

• Actual cleanliness class requirement.

When these inputs are considered honestly, most pharma cleanrooms require far fewer air changes than legacy designs prescribe. This leads to significant reductions in fan energy, filter workload, and HVAC plant size - without compromising compliance.

2. Simplicity Reduces Risk: Every Added Component is a Failure Point

Over-engineering might “look” impressive on drawings, but in practice, it introduces:

• More mechanical points of failure,

• More controls that can drift out of calibration,

• More motors, sensors, dampers, and valves to maintain,

• More downtime during breakdowns,

• More energy is wasted in everyday operation.

In pharmaceutical cleanrooms, where uptime and consistency are critical, simplicity supports reliability. A streamlined cleanroom HVAC design:

• Uses fewer moving parts,

• Reduces maintenance burden,

• Improves system predictability,

• Facilitates troubleshooting,

• Minimises lifecycle cost.

A cleanroom HVAC system should be elegant, not complicated, delivering exactly what is required for GMP compliance, no more and no less.

3. Efficient Cleanroom HVAC Improves Compliance, Not Compromises It

Some stakeholders worry that simplified systems may appear “less GMP.” But regulators evaluate outcomes, not the number of components installed.

A clean, controlled environment with stable pressure cascades, suitable air cleanliness, and validated performance is always acceptable - even if the HVAC plant is refreshingly straightforward.

In fact, designing efficiently often improves GMP alignment:

• Fewer components = fewer deviations,

• Easier maintenance = reduced contamination risk,

• Lower operational stress = longer equipment life,

• Optimised airflow = more stable environmental control.

Regulators care about how well the system works, not how complicated it is.

4. Reasonable Design = Better Energy Efficiency and Sustainability

Cleanrooms are some of the most energy-intensive spaces in any manufacturing facility, and HVAC is usually the biggest contributor.

When ACRs and system components are right-sized, companies can achieve:

• Significant reduction in energy consumption,

• Smaller chiller and boiler loads,

• Longer filter life,

• Lower utility bills,

• Lower carbon footprint.

With the pharmaceutical industry growing more environmentally conscious, efficient cleanroom HVAC design is not just a cost decision - it’s a corporate responsibility.

5. Practical Guidelines for Optimised Cleanroom HVAC Design

Here are core principles for avoiding over-engineering while staying compliant and efficient:

• Start with a process-driven contamination risk assessment Let the process dictate what the room needs - not tradition.

• Make ACRs an output, not an input Use particle profiles, occupancy, and heat load to determine the minimum effective rate.

• Keep airflow patterns simple and predictable Avoid unnecessary turbulence and overly complex ducting geometries.

• Standardise components where possible Reduces spare parts inventory and maintenance difficulty.

• Use robust control strategies, not complicated ones PID loops and pressure cascades should be reliable, minimal, and easy to validate.

• Validate that the simplified system meets all GMP criteria Regulatory acceptance is based on performance verification, not design philosophy.

Conclusion: The Future of Pharmaceutical Cleanrooms Is Intelligent Simplicity

As the industry evolves, so does the approach to cleanroom HVAC design. Leading manufacturers now recognise that over-engineering is not a badge of honour, it’s a liability. Excessive air change rates, oversized systems, and needlessly complex controls create high costs, higher failure risks, and operational inefficiencies.

The modern direction is clear: Optimised, simple, compliant, and sustainable HVAC systems are the future of pharma cleanrooms.

By focusing on real contamination-control needs, following GMP principles, and designing with moderation rather than excess, pharmaceutical companies achieve cleaner, more reliable, and more cost-efficient environments.

Get in Touch

To discuss your pharma cleanroom project that benefits from MRC’s world-class, optimised HVAC design, call us on +971 4883 5908 or complete the contact form.