In this project, Venfeld will combine Virtu tubes (for sun from the roof) with a heat pump on the same buffer with the tubes on a spiral at the bottom and the heat pump on a spiral at the top. This results in a healthier energy mix and lower energy consumption with a higher density per m2 of used roof. With this, 700W per m2 can be removed from a roof n, with an irradiation 840w per m2 or higher (this also happens regularly in winter). The advantage of a vacuum tube is that there is no loss due to ambient temperature. More info: venfeld.com.