Avoiding Overengineering in MVHR and Air Conditioning Installations

Overengineering is one of the most common—and costly—mistakes in mechanical design.

For main contractors, architects, and developers working across Hampshire, Berkshire, and Surrey, the risk is clear: systems that exceed requirements, overcomplicate installation, and introduce unnecessary costs without adding value.

At ClimateWorks, we help project teams specify and install air conditioning and MVHR systems that meet the brief—no more, no less. This blog outlines how we avoid wasteful design and why simpler often means better.

What does overengineering look like?

We’ve seen examples across all types of projects:

• Oversized ductwork that reduces ceiling height
• Excessive zoning that complicates controls
• Redundant backup systems that add cost without risk mitigation
• Unnecessary cooling in rooms with natural ventilation
• Complex routing to avoid non-existent obstacles

These systems often fail to perform better and usually end up harder to install, maintain, and control.

Why it happens—and how we prevent it

Overengineering usually stems from:

• Using default templates instead of site-specific data
• Planning before architectural coordination is complete
• Covering uncertainty with capacity instead of design clarity
• Trying to meet every client request without feasibility checks

We prevent this by:

• Running accurate load calculations from client layouts
• Challenging unnecessary requirements early
• Coordinating with architects and engineers at RIBA Stage 3
• Proposing streamlined duct and unit layouts

Project examples from Hampshire, Berkshire, and Surrey

Winchester – New build overdesigned by M&E consultant

The original spec included two MVHR systems and oversized ductwork. After review, we consolidated it into one balanced system using semi-rigid radial ducting. The result: less disruption to structure, simpler controls, and £7,500 saved.

Guildford – Renovation with oversized cooling

A ducted AC system was proposed for a property with high natural ventilation. We switched to high-wall units in living areas and reduced the system size. Installation time halved, and acoustic performance improved.

Reading – Developer-led housing scheme

An initial layout included dual systems per unit. We analysed usage and consolidated zones. Units were moved to central service spaces and ducting simplified. The change saved over 20% in equipment and labour costs.

How we balance performance with simplicity

Our process:

• Align with project priorities (comfort, noise, compliance)
• Design to meet—not exceed—Part F and Part L
• Select compact units and matched duct systems
• Limit the number of grilles and controls where practical
• Maintain future service access without redundant allowances

We reduce cost and install time while meeting spec and user expectations.

What architects and contractors gain

Choosing ClimateWorks for early-stage input means:

• No costly redesigns after install clashes
• Faster installation with fewer variations
• Better acoustic and visual integration
• Easier maintenance post-handover
• Lower project costs with verified performance

In towns like Basingstoke, Camberley, and Wokingham, developers value our focused design work that strips away excess and delivers what’s needed.

Don’t let complexity ruin performance

Overcomplicated systems often:

• Increase failure points
• Lead to user confusion and misuse
• Reduce efficiency from poor zoning or controls
• Cost more to service and commission

We keep it lean, aligned, and site-specific—protecting your budget and the build.

About the author

Dr. Julian Carter
Thermal Systems Expert and Technical Advisor at ClimateWorks

Dr. Julian Carter is a highly experienced thermal systems expert with over 15 years in the field, holding a PhD in thermal systems. His career spans academic research, consulting, and teaching, focusing on air conditioning and refrigeration systems. Dr. Carter bridges the gap between theoretical advancements and practical applications, providing expert insights to organisations like ClimateWorks, where his guidance informs decision-making and industry best practices. Notably, he has worked on international projects with organisations such as Daikin Industries, the International Institute of Refrigeration (IIR), and the United Nations Environment Programme (UNEP). Currently a lecturer at Edinburgh University, Dr. Carter combines his expertise with a passion for educating the next generation of engineers and advancing climate control technologies.

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