Hills Solarsolar components - archive

Hills 22 Evacuated Tubes Retrofit Kit

Hills 22 Evacuated Tubes Retrofit Kit


Evacuated tube technology delivers significantly better performance than traditional absorbers on the market today. Their advanced design incorporates tubes that consist of 2 layers of borosilicate glass with a vacuum layer between them. The vacuum acts like a thermos flask, retaining up to 97% of the thermal energy, resulting in an increased efficiency.  The Sun's thermal energy is then transferred to the manifold via the heat pipe located in each tube.
The small amount of evaporative liquid in each tube is super heated by the sun's energy and forms into a gas. The gas  rises to the top of each pipe. Heat transfer then occurs between the pipe and water passing through the manifold . The water is then transferred to the tank.
The cylindrical design of the tubes ensures effective collection of the sun's thermal energy throughout the day.


Hills Solar Evacuated Tubes are frost tolerant and have passed the AS/NZ 2712  2007 Standards for both, Hail & Freeze Resistance. The Hills Solar Hot Water Systems have passed the Freeze Test to –15° C without the need for a heat exchanger or Glycol.


A Hills Solar Evacuated Tube hot water system can efficiently capture this free energy and provide you with up to 80% savings on your hot water heating costs. Considering Australia is one of the sunniest countries on the planet it makes sense to utilise this resource by installing a Hills Solar Evacuated Tube hot water system. Not only will you save money but you will also reduce your family’s CO2 emissions by up to 3 tonnes per year.


Retrofit Kit Comprises Following Components


  • 22 Tube collector system inc manifold, tubes and standard frame

Evacuated Tube Features


  • Hills Solar evacuated glass tubes provide superior daily heat output due to the cylindrical absorber always being perpendicular to the sun.
  • Insulation properties of the vacuum in the Hills Solar evacuated tube allow 92% of the heat from the sun to be retained.
  • Heat is rapidly transferred from the copper heat pipe and header to the circulating water from the storage tank, passing through a well-insulated manifold, ensuring maximum solar heat gain.
  • The Rockwool insulated collector manifold, sealed evacuated tubes and freeze-protected heat pipes allow reliable operation even in the coldest areas1 and on cloudy or overcast days.
  • Due to their cylindrical shape Hills Solar evacuated glass tubes are naturally self-cleaning when it rains and thus don’t lose performance through the accumulation of dirt and pollutants.
  • The internal copper manifold pipe in the Hills Solar collector is 35mm in diameter, ensuring greater water flow and is excellent for thermo siphon systems
  • For both gas and electric boosted systems, the Hills Solar collector uses advanced heat pipe technology to provide not only high solar conversion efficiency but also protection against freezing and leaking of any water through the evacuated glass tubes
  • The stainless steel collector frame provides both strength and long-term corrosion resistance.
  • Easy installation and reliable operation is ensured through automated pump operation, low temperature protection and pre-wired power and sensor leads via the Hills Solar controller.
  • Evacuated Tube Collectors are up to 40% more efficient than standard Flat plate Collectors per square metre of aperture



  • 10 Years Warranty*

Evacuated Tube Technical Specifications


Measurement 22 tube collector
Weight 82 kg
Height of collector(inc manifold) 2000 mm
Width of collector 1845 mm
Surface area of collector 3.69 m˛
Absorber area of collector 1.76 m˛
Aperture area of collector 2.086 m˛
Water that manifold in collector holds 1260 ml
Weight of low pitched roof frame 10.5 kg
Weight of a frame (for flat roof) 11.5 kg

Downloads and Manuals



Solar hot water quote


This is an archive page for information purposes only.
  • Model: HRET 22
  • Shipping Weight: 82kg
  • Manufacturer:
    Hills Solar

This product was added to our catalog on Monday 01 October, 2007.