Solar Collector with heat pipe 1,high heating efficiency 2,easyly installation, energy-saves 3,competitive price Solar Collector with heat pipe Material: 1.Heat Pipe:Red Copper,anti-freezing about ≥35°c2 ... .Flow Range Recommendation:50-1501m²/h8.Inslution thickness:40mm9.Min. Collector Angle:15degree10.Max. Collector Angle:75degree