Abstract: This heat recovery device is of the type comprising a vat for holding wastewater and a heat exchanger comprising at least one heat exchange plate comprising two opposite faces and an inner pipe for circulation of a heat transfer fluid between the two surfaces. According to one aspect of the invention, the or each plate is arranged in a heat exchange compartment of the vat so that the wastewater circulates substantially vertically from bottom upwards along the two opposite faces of the or each plate between an inlet of the heat exchange compartment located in the lower portion and an outlet of the heat exchange compartment located in the upper portion. Application to thermal systems with heat pump.

Abstract: A heating system with recovery of waste water heat, of the type comprising a heat pump, a waste water holding vat comprising a casing defining an internal space for holding the waste water; and a heat exchanger to recover calories in the holding vat and use them in the heat pump. The holding vat comprises at least one baffle extending in the holding space and dividing the holding vat into a plurality of compartments and defining, with the casing, a waste water flow path that bypasses the baffles and passes into the compartments, the heat exchanger being positioned so as to recover calories in at least two compartments.