Solar and underfloor heating

Heating regulator was built for floor heating and later extended for solar heating. Lacking of standard regulators capable of driving up to four independent circuits I have decided to build one of my own.

Heating system description

The project power of the boiler is 17kW. As we decided for floor heating, I wanted to controll each flat temperature with mixing valve. 4-way mixing valves are necessary for floor heating because return temperature is too low to be directcy drawn into boiler return. Hot water is transported from dividing bridge through the ground from garage with duct to house. Duct is made of 100mm styrofoam in rectanqular cross-section of 300x400mm. Duct has 3 forward, 3 return PEX pipes of 25x2.3mm diameter. Warm and cold pipes are separated with 10mm EPS. Duct also holds two 16x2m sanitar hot water pipes for circulation. The length of the duct is 11m. Every flat has its own registry divider.

Solar and underfloor heating regulation controller

Front view of the controller Side view of the controller Heating system Dividing bridge

Application software


Software is divivided into this main parts: Binary code is approx 16KB in size and >3000 lines of source code.


Some LOG files and plots from operation of the controllereare available .
Last modified: Wed Apr 20 11:23:34 CEST 2005