Datum Phase Change Limited and Airtherm Engineering Limited are specialising in incorporating phase change materials into building products under the brand name ThermaCool™, for use in both new build construction and retrofit of commercial and residential buildings. ThermaCool™ products are passive systems incorporating a microencapsulated phase change material that increase the thermal mass of lightweight and super insulated buildings and will reduce the energy consumption of climate control systems in buildings. From an economic perspective ThermaCool ™ products are best used for supplying additional cooling capacity during hot weather and savings can be made on the mechanical cooling system and more use can be made of free (night time) cooling via an Airtherm's 'Wind-iVent' natural ventilation systems.