heat pipe solar collector

Vacuum tube: 
   Length: 1800 mm (70.8") 
   Outside dia.: 58 mm (2.28") 
   Inside dia.: 47 mm (1.85") 
   Wall thickness: 1.6 mm (0.063") 
   Weight: 2 kg (4.4lbs) 
   Material: borosilicate glass 3.3 
  
   Selective surface: Cu / SS / AL N triple deposition 
   Absorbtance (a): +95% @ AM 1.5 
   Emissivity (e): 5% @ 80deg C 
   Vacuum: P=5x10^-3 PA 
   Thermal expansion: 3.3x10^-6 deg C 
   Heat loss: 0.8 W/m2 deg C 
  
   Hail resistance: 25 mm 
   Warranty: 5 years 
  
Heat pipe: 
   Dimensions: 8 x 1750 mm 
   Efficiency: +95% 
   Heat transfer fluid: non-toxic inorganic refrigerant  
   
15 vacuum tube collector: 
   Length: 1780 mm (77.9") 
   Width: 1.65 M (65.25") 
   Height: 170 mm (6.6") 
   Gross area: 3.07 M^2 (33.1 sq ft) 
   Net aperture: 2.01 M^2 (21.64 sq ft) 
   Fluid capacity: 1,300 ml 
   Flow rate: 1 - 1.5 gal/min 
   Pressure rating: 65 psi max working 
   Aperture efficiency: +70% 
   Power - watts (Btu/hr): 1,024 W (3,493 Btu/h) * at STC = 1,000 W/m^2 insolation, Ti - Ta = 10 deg C. 

Our solar collectors Specification: 

solar collector 1.produces more than 20,000 Btu's which will raise 50 gallons of water by 60 deg F.2.widely used for projects