The Helios Fans WHR 315 is a compact water heater battery designed for use with circular ducting systems. Its casing is made from galvanized steel for durability and corrosion resistance. Each end is equipped with spigots featuring double lip rubber seals to ensure a tight fit with standard nominal ducts. The heating elements consist of copper pipes with aluminium fins, enabling efficient heat transfer. The unit supports a maximum operating temperature of 100 °C and a pressure of up to 8 bar. For straightforward installation and maintenance, two inspection caps are positioned on the water connection side.