How are all these systems controlled?

If technology and the detail explained on these pages confuses you or "puts you off" considering renewable energy systems then remember that once it has been set up for you by the installers it can be left to look after itself automatically.  There is no need to worry about changing things but you could, at some stage, have a go at changing the temperature or timing of a thermostat if you so wished.  If not, just leave it to do what it was designed to do by itself!  However, if you are like me, you could monitor the systems, develop spreadsheets and produce charts and graphs for sharing with others on a website! 

The Velux windows and shutters are radio controlled using a TV type remote. They can be programmed to open/close automatically at certain times of day or used manually. The external shutters can keep the sun's heat out on hot days or allow free heat in during cooler seasons. The solar thermal system operates totally automatically. When the temperature of the panels is 8 deg C higher than the hot water in the cylinder the pump operates to pump the hot fluid through the cylinder's coil. The pump stops when the temperature difference is 4 deg C or when the hot water has reached its set maximum.

 

Here the Solar Thermal Panels have heated the water to 57 deg C

Fifteen digital low voltage thermostats are positioned throughout the house and can be individually monitored and programmed by hand, on a local computer or on a remote computer from anywhere in the world!  The buttons below the thermostat's display can be used manually to set the times and temperatures for the room which it controls.  The unit can also be "locked" to stop little fingers playing with it!

When a room thermostat calls for heat an actuator opens a valve to allow hot water to flow in a loop in that room.  The white cubic devices are the actuators and can be seen on the upstairs underfloor heating manifold in the photograph below.

The GSHP will supply more heat to a buffer tank, sometimes called a thermal store, when necessary to maintain the heating water supply. All of this is automatic but the temperature of the heating water and domestic hot water can be adjusted if desired. After initial set-up it can be left to control itself.

The picture above shows the REGO control panel for the Worcester-Bosch GSHP.  The green light at top right shows that the heat pump is drawing heat energy from the soil via the collector pipes under the front lawns.  The green light bottom left is just the On/Off indicator for the GSHP.  The other 3 indicators, going clockwise, are a Fault Warning, Hot Water being heated by the pump and Additional Heat being provided by an in-line electric immersion heater.  This electric heater is only ever used in very cold conditions and then only very briefly. 

The 3 buttons below the display and the rotary control knob are used to programme the computer in the unit and also to select various temperature sensors which are connected to it.  For example, the temperatures of the fluid coming in from the collector pipes under the ground and going out again from the GSHP can be viewed.  Typically these two temperatures only differ by around 3 degC but, amazingly, this small temperature difference is sufficient to enable the heat pump to meet all our heating and hot water requirements. 

The display in the picture shows the temperature of the hot water going out to the underfloor heating system, see below, and the target temperature at which the GSHP will stop heating this water.  This target temperature can be adjusted using the control panel but it will also vary automatically in response to weather conditions using sensors on the north-facing wall of the house and in the main hall.

The photograph below shows the underfloor central heating pipework being installed upstairs with the "spreader plates" to conduct heat more evenly across the floor area.  Note the insulation under the plates and pipes to reduce the heat transfer to the ceiling of the room below and ensure that the the heat travels mainly upwards to the bedroom.  The bedrooms have a special heat conducting underlay beneath the carpet to improve the heat flow, rather than the usual type of underlay which would act as an insulator.

The UFCH pipes, insulation and spreader plates upstairs during installation

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