The Sustainability Benefits of Refurbishing Existing Ventilation Equipment
28/08/2026

As your ventilation system reaches the later stages of its working life, replacement can seem like the obvious choice.

Improved efficiency, modern controls, and updated components all make new air handling units (AHUs) look attractive. But replacing old equipment also has a significant environmental cost. And it’s this cost that can be the key issue when you’re trying to decide the most sustainable route forward.

In the right circumstances, and with the supporting calculations to prove it, choosing to refurbish existing ventilation equipment can result in reduced waste and lower levels of embodied carbon compared to installing a new unit.

Making sure you have a basic understanding of embodied carbon is the first step in your decision.

What is embodied carbon?

Ask most people about the carbon impact of their HVAC unit, and they’ll tend to think about how much energy is used when the machine is turned on.

Less obvious, though, are the greenhouse gas emissions associated with the equipment throughout its life. CIBSE’s TM65 methodology considers emissions linked to manufacture, installation, maintenance, repair, replacement, and end of life.

For ventilation equipment, these ‘unseen’ greenhouse gases can be significant. Large units often contain substantial quantities of steel, aluminium, and iron, all of which have an associated carbon footprint.

So while a new unit might use less energy when it’s running, its environmental impact began long before it was ever switched on.

The full environmental cost of replacing HVAC units

Replacing an existing AHU also involves more than manufacturing a new unit.

Consider also the greenhouses gases used in its transportation to site, the dismantling and removal of the old unit, and the installation, connection, and commissioning of the new unit.

Any associated construction work, like modifications to ductwork or electrical systems, also come with their own environmental cost.

None of this means replacing old equipment is always the wrong sustainability choice. It’s just that both sides of the equation should be considered.

Extending the life and performance of HVAC equipment

Refurbishment is the single biggest thing you can do to improve both the lifespan and the ongoing performance of your existing AHU.

From minor tasks, like replacing worn or inefficient components, through to upgrading fans and motors or repairing damaged sections, the amount of refurbishment needed depends on the AHU’s current condition.

Even relatively small but targeted improvements can improve both the reliability and performance of an existing AHU. This also means fewer waste materials, with the majority of an existing unit staying in place and only specific elements being replaced.

CIBSE’s guidance on existing building services highlights the importance of considering restoration and retrofit alongside replacement. It also offers a starting point for embodied carbon calculations. This helps you to better identify, given the importance of whole-life performance, whether refurbishment or replacement is the greener option for your specific circumstances.

Refurbishment as part of a wider sustainability strategy

Existing buildings will play a major role in reducing carbon emissions, which means retrofits and refurbishments are set to become more prominent than ever. But they’re not always the right approach. Sometimes, installing from new is the only sensible way forward.

A comprehensive sustainability strategy recognises these two options can co-exist, even within the same building. What’s key is the best whole-life outcome, rather than the option that best aligns with a belief rather than an evidence-backed case.

Good sustainability strategies also look at a series of other initiatives: reducing unnecessary energy use, improving controls, and maintaining equipment properly can all contribute to better building performance.

Refurb or replace? Our experts are ready to help

Before committing to a full replacement, it’s worth assessing whether your existing ventilation equipment has useful life remaining.

Air Vent Technology can assess existing systems and advise on potential refurbishment or replacement options, helping you understand whether upgrading or replacing your equipment is the most appropriate route.