The warm water heat pump Vitocal 161-A is a sustainable and environmentally friendly unit that derives heat for warm water from the ambient room temperature. The resulting cooler air is used to ventilate and cool living quarters. The cylinder’s powerful design is contrasted by the calm, geometric form of the vertical panel that hides the technical elements. This results in operating controls that are easy to understand and have been reduced to the essentials. The compact, space-saving housing contains not only the heat pump but also a 300-litre boiler. This integrative design concept contributes to a reduction of complexity and provides maximum benefits and convenience for the user.