Technical Data
Coating of absorber: one side (Standard) NARVA Vacuum tube
direct flow		 NARVA Vacuum tube
heatpipe
Nominal length 800 1.500 1.775 2.000 800 1.500 1.775 2.000
Length of glass tube (mm) 810 1.510 1.785 2.010 810 1.510 1.785 2.010
Diameter of glass tube (mm) 56 56
Length of connecting pipe (mm) 57 30,5
Aperturface of glass tube (m²) 0,0386 0,0750 0,090 0,1010 0,0386 0,0750 0,090 0,1010
Nominal tube output (W)
at an irradiance of 1000 W/m²		 30 59 71 80 28 56 67 76
Absorbed heat at 1000 kWh/a*m² global
radiation temperature difference 40 K (kWh/a)		 27 53 64 72 25 50 60 68
Absorbed heat at 1000 kWh/a*m² global
radiation temperature difference 100 K (kWh/a)		 23 45 54 61 21 42 50 57
Heat transmission coefficient linear (W/m²*K) 1,12 1,12
Heat transmission coefficient quadratic (W/m²*K²) 0,004 0,004
Efficiency factor 0,781 0,750
Instructions for use - As a result of the flat
  characteristic of the tube it
  may be used for continous
  operation at a temperature
  of the heat carrier up to 150 °C
- The tubes fulfil the
  requirements according to
  DIN EN 12975-2
- The tubes are designated for
  a lifetime of 20 years
- If there is a risk of frost there
  should be used a
  corresponding heat carrier
- The temperature of lost
  motion can reach 315 °C		 - The vacuum tubes are working
  up to an angle of 20 degrees
  without any performance loss.
- The tubes fulfil the
  requirements according to
  DIN EN 12975-2
- The tubes are designated for
  a lifetime of 20 years
- The switch off temperature
  is 160 °C
Order numbers
Nominal length NARVA Vacuum tube direct flow NARVA Vacuum tube heatpipe
Standard Power Standard Power
    800 1301 / 003 1301 / 012 1302 / 007 1302 / 004
1.500 1301 / 002 1301 / 014 1302 / 008 1302 / 006
1.775 1301 / 016 1301 / 017 1302 / 013 1302 / 014
2.000 1301 / 006 1301 / 005 1302 / 001 1302 / 005