Closed flat solar collector Thermal insulation

Thermal insulation: normally made of glass wool, rock wool or expanded polyurethane, thermal insulation is used on the bottom of the solar collector and on some products also on the sides. Its function is to inhibit thermal losses from the bottom and from the side. Among the materials used, polyurethane stands out due to its mechanical resistance, low thermal conductivity and because it does not have hygroscopic characteristics such as glass wool, which can drastically impair the efficiency of the solar collector, if there is any water infiltration.