Andújar Márquez, José ManuelMartínez Bohórquez, Miguel ÁngelGómez Melgar, Sergio Jesús2018-01-162018-01-162017Andújar Márquez, J.M.; Martínez Bohórquez, M.Á.; Gómez Melgar, S. A New Metre for Cheap, Quick, Reliable and Simple Thermal Transmittance (U-Value) Measurements in Buildings. Sensors 2017, 17, 2017.1424-8220http://hdl.handle.net/10272/14237This paper deals with the thermal transmittance measurement focused on buildings and specifically in building energy retrofitting. Today, if many thermal transmittance measurements in a short time are needed, the current devices, based on the measurement of the heat flow through the wall, cannot carry out them, except if a great amount of devices are used at once along with intensive and tedious post-processing and analysis work. In this paper, from well-known physical laws, authors develop a methodology based on three temperatures measurements, which is implemented by a novel thermal transmittance metre. The paper shows its development step by step. As a result the developed device is modular, scalable, and fully wireless; it is capable of taking as many measurements at once as user needs. The developed system is compared working together on a same test to the currently used one based on heat flow. The results show that the developed metre allows carrying out thermal transmittance measurements in buildings in a cheap, quick, reliable and simple way.engAtribución-NoComercial-SinDerivadas 3.0 EspañaAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/U-valuethermal transmittanceenergy retrofitting of existing buildingswirelessheat flowtemperature sensorsRaspberry PiXbeeArduinojournal article10.3390/s17092017open access