A 50/50 propylene glycol and water mixture from the collectors through a coil of pipe in the solar tank, and then is pumped back through the collectors. The potable water is warmed by heat transfer through contact with the pipe. These systems are pretty much the only choice in very cold climates. When there is not enough energy for sun, an electrical or gas back up element will be automatically switched on by controller.
Feature:
Simple Installation, No Maintenance, Effective operation
Easy Retrofitting To Existing systems
Suitable for single and multiple solar heating Application systems,
Preferred option for extremely cold areas and questionable water quality.
Incoming potable water is routed to the solar storage tank
Porcelain Enemal or SUS316 Stainless Stee Storage Tank With Electrical or gas Back Up
Double-walled Copper Coil heat exchangers in storage tank prevent contamination of household water.
Structure and priciple:
The heat pipe is hollow with the space inside evacuated, much the same as the solar tube.
Freeze Protection: Because the heat pipe is located within the evacuated glass tube, biref overnight temperatures as low as -20oC will not cause the heat pipe to freeze.
 High heat conduction coefficient: Is 2000-  High heat conduction coefficient: Is 2000-5000times of metal materials
 Low temperature difference: Less than 4oC difference in 2 meter long pipMODEL  Lighting(m2)  Heat pipe  Supply hot water(L/oC)  20/40containner  GW
KG
   diameter  lengh  No.      
HK47/12  1.26  ¦µ47mm  1500mm  12  70/60    28
HK47/18  1.80      18  110/60    42
HK47/20  2.10      20  125/60    46
HK 47/30  3.15      30  180/60    69
HK 58/12  1.73  ¦µ47mm  1800mm  12  110/60    40
HK 58/18  2.57      18  150/60    60
HK 58/20  2.88      20  175/60    64
HK 58/30  4.32      30  260/60    98