The Truth on Solar Collectors & Hydronic Heating

Hydronic Underfloor Heating for Existing Homes
October 6, 2014
Show all

The Truth on Solar Collectors & Hydronic Heating


Some solar companies in Australia are making promises of solar collector plates providing 100% of the heating requirements for potable water as well as swimming pools and hydronic heating. This is not currently possible and we write this post to empower the Australian consumer.

Far too often, we’re called to fix malfunctioning hydronic systems in New South Wales. The common mistakes we see are tradesmen installing the hydronic system in combination with a solar thermal system with either no-backup heat source or the incorrect hydraulic setup.

The solar contribution for a hydronic heating system on the best possible yield per annum is typically 10-15%, a backup heat source is always necessary in all hydronic heating applications. Throughout our experience in Ireland, Germany, the Greater UK region, India and China – we have seen countless solar collectors with thermal storage tanks. The primary draw from the solar thermal tank is allocated to the potable water, i.e. that’s the showers, kitchen sink, wash basins and laundry.

There has not been a successful hydronic heating project for a standard home (i.e. non-Passive House) that has run purely off solar thermal heating without a backup heat source either through a gas boiler, electric boiler or a heat pump. There have been projects for the Passive House constructions, however these are few and far between and Passive House constructions typically have minute heat loads allowing very minor call for the heating.

For any further detail or enquiries please feel free to contact the author Harry Rao at or on 0426 381 371

Solar powered underfloor heating systems sydney, melbourne, perth

hydronic bathroom heating systems in australia

© 2015 Liquid Transition.
All Rights Reserved.