Residential Space Solar Heating by Thermally Activating the Space Roof Structure Using Evacuated Tube Solar Collector in Iraq

The space of a residential building is heated by circulating heated water from two parallel evacuated tube solar collectors through a galvanized steel water coil embedded in the concrete layer of the roof construction of building located in Missan city/ Iraq. The test room measures (5.5 m x 4.0 m) with three walls exposed to the outdoor conditions in addition to the roof. The roof of the test room was mainly constructed of 100 mm turf, 50 mm Styrofoam insulation, 200 mm heavy weight concrete. The heated water was provided using two parallel evacuated tube solar collectors, 120-liter capacity each. Water coil consists of 22 galvanized water pipe of 13 mm diameter, 4.5 m long each and 17.5 cm spacing. The result was focused on comparing space indoor conditions, system performance and the power savings obtained with and without roof activation. Also, the effect of turf roofing and roof insulation on indoor conditions was studied. The results show that the indoor conditions is out comfort level from 14 December till 7 February based on 20 ˚C setting temperature with inactive roof while it is within comfort level with roof activation. Also, it was found that the indoor temperature with roof activation in any day can be estimated as the maximum temperature during that day. The power saving was found 73.8 % with 𝑇set= 20 ˚C. The indoor conditions with turf and roof insulation increased by 4.5˚C compared with that of without activation.