In the present work, solar water heater (SWH) equipped with a hindrance promoter is reported as a substantial and impressive design development which has been utilized to increase thermal enhancement of the SWH. An experimental study is performed to analyze the influence of distinct parameters of the hindrance promoters on heat transfer and friction factor in SWH. The distinct parameters of the upstream delta-winglets imposed on both sides of the copper strip inserted into the absorber tube, are pitch ratio (P-Rd) the blockage ratio (B-Rd), angle of attack (alpha(w)) and spacer length (S-w). The P-Rd varies as 0.5, 1.0, 1.5 and 2.0, the B-Rd varies as 0.1, 0.15, 0.2 and 0.25, alpha(w) varies as 15 degrees, 30 degrees, 45 degrees and 60 degrees, S-w varies as 0, 200, 400 and 600 mm and Reynolds number (Re) ranges from 200 to 1800. The experimental outcomes show that hindrance promoter with parameter P-Rd = 0:5, B-Rd = 0:2, a(w) = and S-w = 0 mm affect Nu(w) and integral w substantially. The improvement obtained in Nusselt number (Nuw) is 4.56 times higher than smooth tube. The thermo-hydraulic performance (eta(w)) of 2.62 is obtained using hindrance promoter having parameters P-Rd = 0:5, B-Rd = 0:2, a(w) = and S-w = 0 mm. (C) 2020 Elsevier Ltd. All rights reserved.