gtc solar are professionally producing heat pipe solar collector, and solar water heater with solar kemark,en12975 standardsolar water heating system, and solar project like swimming pool, floor heating,room heating, hotel and scool hot water using field....our products already get CE ROHS ISO certification, and also give garrantee for our GTC solar system. 5 years for whole unit, 10 years for vacuum tube and heat pipe, performance more than 15 -20years.we have made the united union project and lots of 5star hotel and pool project. more information see our web at ww gtc-solar.com .also please kindly send us your company full information!!! 1) Model no.: GTC-58-alu 2) Adopts U pipe technology 3) No of tubes: 18, 20, 24, 30 4) Disassemble: no 5) Total length (m): 1.65/1.90/2.00/2.45 6) Total width (m): 1.9 7) Gross absorb area (m²): 3.14/3.50/3.80/4.66 8) Aperture area (m²): 2.52/2.96/3.36/4.20 9) Surface absorber (m²): 2.18/2.30/2.42/3.03 10) Reflector: non 11) Operation pressure (Bar): 8 12) Entry connector size: ½" male/copper tube 13) Material of manifold: anodized aluminum, 2mm 14) Material of U pipe and manifold head: TU1 copper 15) Insulation of manifold: polyurethane 16) Slot of thermic sensor: yes 17) Cold resistance: -30 18) Liquid capacity: 2.8/3.2/3.80/4.70 19) Total weight (kg): 39/42/47/65 20) Min. flow (L/m): 120 21) Typical flow (L/m): 150 22) Max. flow (L/m): 600 23) Stagnation temperature (°C): 300 24) EN 12975 (solar keymark) in course 25) Date: October 15 26) Efficiency (n0 in %, k1 in W/m²K, k2in W/m²/K²); n0=0.77, k1=1.47, k2= 0.0051 Tubes: 1) Hail resistance: ≤25 2) Diameter of tube (mm): 58 3) Glass quality: borosilicate, 3.3 (T=0.91) 4) Thickness (mm): 1.7 5) Vacuum degree (Pa): 3 x 10-3 6) Absorb rate: ≥0.94 7) Reflecting emission: <0.06 8) Material of coating: SS-C/CU solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector, solar water heater collector,