... absorptive with an average daily performance efficiency over 50% ;B)Quick start-up, heat pipe transfer the heat energy into the storage ... : heat pipe vacuum tubeA) Size: 58 x 1800mm /47mm×1500mm B) Qty: 15, 20, 25 and 30 pcs * Insulation layer: A ... ) Material: Imported polyurethane from Bayer Germany B) Thickness: 50mm (maximum 72 hours conservation)C) Density: 42 kg ...