Solar heating by radiant floor: Experimental results and emission reduction obtained with a micro photovoltaic-heat pump system Articles uri icon



publication date

  • June 2015

start page

  • 297

end page

  • 307


  • 147

International Standard Serial Number (ISSN)

  • 0306-2619

Electronic International Standard Serial Number (EISSN)

  • 1872-9118


  • An experimental research with a solar photovoltaic thermal (PVT) micro grid feeding a reversible air-water, 6 kW heating capacity heat pump, has been carried out from December 2012 to April 2013. Its purpose is to heat a laboratory that is used as a house prototype for the study of heating/cooling systems. It was built in accordance with the 2013 Spanish CTE, and has an area of 35 m(2) divided into two internal rooms: one of them housing the storage system, the solar controller, the inverter and the control system; the other one is occupied by three people. Its main thermal characteristics are: LIA = 125 W/degrees C and a maximum thermal load about 6.0 kW at the initial time. The PVT field consists of 12 modules, vvith a total area of 15.7 m(2) and useful area of 14 m(2). Each module is composed of 48 polycrystalline silicon cells of 243.4 cm(2), which with a nominal efficiency 14% can generate a power of 180 W, being the total nominal power installed 2.16 kW. The PV system stores electricity in 250 Ah batteries from where is converted from DC to AC through a 3.0 kW inverter that feeds the heat pump. This works supplying 8401/h of hot water at 35-45 degrees C to the radiant floor. The data storing system is recording variables such as solar radiation; temperatures; input power to batteries; heat produced; heat transferred by the radiant floor; heat pump's COP; isolated ratio; and solar fraction. The objective of this work is to present and discuss the experimental results and the emission reduction of CO2 obtained during the period from 01/12/2012 to 30/04/2013, including the detailed results of two representative days of Madrid's climate: 28/12/2012 using only PV electricity and 21/01/2013 mixing PV and conventional electricity. The heat pump worked