Pressurized Glycol Solar Hot Water Panels System
This means that the potable water that enters your home does not come in direct contact with the Sun’s rays. Rather a heat exchanger is used to transfer the heat from the heating-fluid (often a mixture of propylene glycol and water which helps prevent freezing of the fluid in colder climates) to your potable water.
It’s the heating-fluid that flows through the collector absorbing heat from the Sun’s rays and then enters the storage tanks heat exchanger where it heats your potable water.
Since these systems are a little more complex they require a few extra components like an expansion tank as well as components necessary for filling, venting and maintaining the system.
However, these added components are what allows this system to be installed in very cold climate, thanks to the system’s anti-freeze heating-fluid.
Take a look at the diagram below to get a better understanding of how this type of solar hot water system works.