Flexible Flow Sensors for Air Conditioning Systems Based on Printed Thermopiles.

Air conditioning systems need permanent monitoring of the mass and energy flows in air ducts to assess their proper operation and detect and correct changes that may occur with time. This is a prerequisite for optimization in terms of energy efficiency. Such distributed monitoring systems require low-cost and robust flow sensors that must not be extremely precise, but give a good indication of the flow distribution within the air conditioning system. In this paper we present a novel flow sensor based on thick-film thermopiles deposited by silk-screen-printing on a plastic carrier. The flexible printed thermopile transducer was characterised in a flow channel to demonstrate the feasibility of the technology for air conditioning systems. The transducer exhibits a strictly increasing behaviour with increasing flow velocity, which is in good agreement to FEM simulations. [ABSTRACT FROM AUTHOR]