A phase change for the better

PCMs Explained

PCMs (phase change materials) are materials that undergo a phase change transition from solid to liquid and liquid to solid to absorb or release large amounts of latent heat at a relatively constant temperature.

Heat Storage

Heat Release

Reduce Energy Demand

Essentially, PCMs work in the same way as a material with thermal mass - capturing and releasing energy to smooth out peaks and troughs of the heating and cooling cycle. By removing these peaks and troughs, often as a result of air conditioning systems, phase change materials manage the internal temperatures more effectively and efficiently to provide a comfortable working temperature throughout the day.

ThermaCool® Innovation

Through this natural process of phase change, we have used the technology in our ThermaCool® wall and ceiling products, giving both thermal mass to lightweight structures and also significantly reducing the energy demand of climate control systems.

For use in both new build construction and retrofit of commercial and residential buildings, our ThermaCool® products reduce the energy consumption of climate control systems. Our products offer competitively priced, easy to install solutions that yield significant energy and carbon savings for your building.

Tried and tested technology

Layer 1

Ofcom Head Office

Installing ThermaCool’s ceiling tiles reduced the peak heat temperatures by up
to 4.3˚C compared to areas with standard metal ceiling tiles.

Thermal Mass Explained

A thermal mass is a material that absorbs heat from a heat source, and then releases it slowly. In buildings, thermal mass is provided by the structure of the building.

Buildings constructed of lightweight materials such as steel or timber are not considered to have good thermal mass properties compared to concrete, brick and stone.

The ability to absorb and release heat enables buildings with thermal mass to respond naturally to changing weather conditions, helping to stabilise the internal temperature.

Benefit throughout the year

The role of a buildings thermal mass can be of benefit throughout the year. During the warm weather in summer, heat will be absorbed by the thermal mass in order to prevent overheating in the building, providing a more comfortable living or working environment.

During the winter, when heating demands are at their greatest, thermal mass can help reduce fuel consumption by absorbing heat produced from occupants, lighting and IT during the day and then slowly releasing them overnight as temperatures fall, reducing the need for additional heating the following day.


The effectiveness of
thermal mass for reducing summertime overheating has been well established

Stephen Underwood, ThermaCool