U-Pipe Evacuated Tube Solar Collectors are smaller and more compact than SunMaxx Heat Pipe Evacuated Tube Solar Collectors. While the two collectors have nearly identical efficiency ratings, there are several key advantages to U-Pipe Evacuated Tube Solar Collectors. These Include:

  • Extremely Low Price                                                                  u-pipe-working-pic
  • Additional Installation Versatility
  • Compact Size for Tight Installation Locations

SunMaxx U-Pipe Solar Collectors cost less than SunMaxx Heat Pipe Evacuated Tube Solar Collectors, which are already one of the industry’s most affordable lines of solar collectors. The main point here is that U-Pipe Collectors can be installed perfectly vertical or horizontal, allowing for a wider variety of installation options, which allow these solar collectors to be used where other collectors can not be used, such as on the top of a flat roof building where tilt mounting is not an option due to space limitations,  as an overhang from buildings where there is no roof space to mount the solar collectors, or flush vertically on a wall.

Each U-Pipe Evacuated Tube Solar Collectors include:   u-pipe-pic

  • 30 Revolutionary SunMaxx Evacuated Tubes
  • 30 U-Pipe Style Copper Heat Pipes
  • SunMaxx 30 Face Frame w/Assembly Hardware Kit
  • SunMaxx 30 Flush Mount Hardware for Pitched Roofs
  • 10 Year SunMaxx Limited Warranty
  • Customer Support

Assembly Time: A single SunMaxx 30U Solar Collector can be assembled and installed in about 1.5 hours.

Comparison of SunMaxx Heat Pipe Vs U-Pipe Evacuated Tube Solar Collectors:

Test Models:  SunMaxx-30 Heat Pipe, and SunMaxx-30U-Pipe
Testing Report:  Solar Keymark Certification Testing

Model SunMaxx-30U SunMaxx-30
Collector Type
Heat Pipe
Aperture Area 2.67 m2 (28.74 ft2) 2.79 m2 (30.03 ft2)
Conversion Factor (efficiency (no)) 0.650 0.734
Heat Transfer Coefficient (a1) 1.585 W/(m2K) 1.529 W/(m2K)
Temperature Dependent Heat Transfer Coefficient (a2) 0.002 W/(m2K) 0.012 W/(m2K)
Typical Power Output/Collector
Tm – Ta (K)
@ 400 W/m2 @ 700 W/m2 @ 1000 W/m2
@ 400 W/m2 @ 700 W/m2 @ 1000 W/m2
649 1172 1693
772 1387 2001
562 1083 1510
650 1264 1879
469 990 1510
490 1105 1719
Power Output (W/m2 – Aperture Area) based on 1000W/m2 Irradiance 634 W/m2 of Aperture Area 717 W/m2 of Aperture Area
Power Output (BTU/h/m2 – Aperture Area) based on 1000W/m2 Irradiance 2163 BTU/h/m2 of Aperture Area
201 BTU/h/ft2 of Aperture Area
2446 BTU/h/m2 of Aperture Area
227 BTU/h/ft2 of Aperture Area
Total BTU/h 5923 BTU/h 6824 BTU/h
BTU/h/$ Invested (Value of Collector) BTU/h/$ 4.76 BTU/h/$ 3.90

It is clear from the results that the conversion efficiency of SunMaxx Heat Pipe Evacuated Tube Solar Collectors is better than that of SunMaxx U-Pipe Evacuated Tube Solar Collectors.

However, in pure dollar value – BTU/h/$ invested – SunMaxx U-Pipe Solar Evacuated Tube Solar Collectors deliver a higher energy value because of their extremely low price and high performance ratings.

In particular, U-Pipe Solar Collectors are the perfect for installations where the Solar Collectors will be mounted flush (flat) on a zero-pitch (flat) roof, or in a vertical orientation on the side wall of a building.

Some Areas or Graphics Reprinted with Permission: Silicon Solar Inc,  Copyright 2008-2009 All Rights Reserved  DogStar Solar Inc, Copyright 2009