Most solar thermal systems use antifreeze as the liquid to transport heat from the solar panel to the cylinder. However, there are a few drain back systems that only use water. The antifreeze is normally non-toxic propylene glycol (as opposed to toxic ethylene glycol). An antifreeze change may be required for your solar system.
Antifreeze is one word that Solar Thermal installers and owners should understand. For the Solar Thermal contractor, this antifreeze is more accurately described as the heat transfer fluid (HTF) necessary for the proper functioning of solar thermal systems in different regions of the country.
degradation of the antifreeze, leading to acidity. This can potentially lead to corrosion of the pipe work, solar cylinder or solar panel. breakdown of the in-built inhibitors. blockage of liquid channels in the system.
In solar systems operating in moderate climate conditions, it is possible to use environmentally safe water without the addition of substances reducing the freezing point. It is then necessary to apply a solution that protects the system against the freezing of water. In the literature, several solutions can be found:
Freeze and overheat protection are critically important design considerations for solar water heating (SWH) systems. ICC-SRCC certifies and rates SWH systems under its OG-300 certification program, regardless of suitability for use in any specific climate (also known as climate appropriateness).
The anti-freeze protection system consumed annually from 7 to 13% of the heat generated by the collectors in the installation. Supporting the operation of the central heating system in the building during the winter season highly improved the efficiency of the solar collectors.