... from a unit area, less roof occupied;(2) Plate-grid structure, fluid heated in the copper pipe with faster heat transfer ... %, stable performance, life span 50 years;(2)Special design structure, 360°heat transfer, excellent thermal conductivity;(3)Optical low ... heat loss;(4)Integrated frame design, nice outlook, stable structure, easy to install;(5)Integrated polyurethane foaming, thicken back and ...