Hot and cold: Mapping the impact of insulation on commercial HVAC systems.
In schools, office buildings, hotels and industrial facilities, the Heating Ventilation and Air Conditioning (HVAC) system quietly (or in some cases, not so quietly) goes about its day keeping indoor spaces at a comfortable temperature. Yet behind the scenes, it can be one of the largest energy consumers in a commercial building. HVAC systems control the environmental conditions inside a building through ductwork and pipework and every part of that journey is a chance for energy to be lost. That’s why insulation isn’t just for walls and roofs - it’s important to HVAC performance, especially in large and complex spaces. By keeping heated or cooled air at the intended temperature as it moves through the system, insulation helps to prevent heat loss ensuring the correct temperature is delivered to the required location.
What is HVAC insulation used for?
The most immediate benefit of insulating HVAC systems is thermal efficiency. Without it, hot air cools down faster in winter , and chilled water systems warm up in summer, especially as they pass through areas like roof voids or service risers.
Without HVAC insulation, a HVAC system has to work harder to compensate for any energy loss increasing energy consumption and reducing system efficiency. Therefore by using insulation, it reduces the heat losses in the HVAC system, maintaining the system design temperatures.
Another role of HVAC insulation is condensation control – condensation occurs when warm, moist air encounters a cold surface. Cold ducts, or chilled water pipes, can cause moisture to form on their surfaces if they’re not properly insulated. Over time, this condensation can lead to corrosion, mould growth, or damage to surrounding building materials. In educational buildings or healthcare environments, this is can have a negative impact, as moisture-related deterioration can impact indoor air quality and subsequently, the health of those inside.
Properly designed and installed HVAC insulation makes a difference
Insulation is only fully effective when it’s installed and maintained properly. Banding wire should be used where needed, ductwork should be clearly labelled, and foil tapes should be used correctly – and finally ensuring the right insulation product has been specified for the appropriate application.
Common issues include thermal bridges, compressed materials, or the wrong thicknesses - all of which can reduce performance. In retrofits, fitting insulation around existing systems or into tight ceiling voids really needs experience and careful detailing.
Problems with not insulating pipework correctly
When it comes to insulating chilled and cold water system pipework, there are a number of issues that can be caused by using the wrong insulation product or by installing the insulation product incorrectly.
Condensation, dripping pipework, building fabric damage, mould growth and damaged ceilings can all stem from poorly-installed insulation causing issues with moisture. Other issues such as corroded pipework, increased energy consumption, noise breakout and freezing pipes can also occur as a result of poor installation of insulation.
It’s also important to protect personnel from hot pipework, so all hot water pipework should be insulated sufficiently to reduce the surface temperature below 55°C, but you should also bear in mind that anything that still has a surface temperature above the ambient will be losing heat constantly.
To solve these challenges, many building owners and engineers are turning to a more strategic approach – fully mapping their HVAC systems to identify where insulation is missing, degraded, or underperforming. This involves a combination of thermal imaging, pressure testing, and system modelling to understand exactly where energy is being lost and where changes would have the most impact. Isover supports this process by offering product guidance to help project teams specify the right insulation for their needs.
Final thoughts
Whether you're managing a school, planning an office retrofit, or designing a factory from the ground up, HVAC systems are more than a passive layer - it's an active part of your building’s performance and efficiency. By taking a systematic, informed approach to mapping a HVAC system and insulating it correctly, it’s possible to cut energy use, reduce emissions, improve comfort, and extend the life of your systems
HVAC insulation support from industry experts
At Isover, we offer a range of solutions designed specifically for HVAC applications. For example, Isover Climcover, Isover Climpipe, and Isover U‑Protect lines can be tailored for ductwork, pipework and fire-protected HVAC systems, providing not just thermal efficiency, but also passive fire protection.