Eco in France

[rt29781]

Hi we have at last got our Navitron Solar system working in France.  Now the sun refuses to shine just to annoy me....  We also have Solar PV but the authorities are being slow to connect us to the Grid despite all our efforts.  Next we will install a heat pump for the cloudy days.....The full story is on our blog (http://smartfrance.blogspot.com)

[dhaslam]

I wonder if you should be storing solar heat instead of using a heat pump.  You probably have excess heat on sunny days anyway.   During periods of cloudy low pressure conditions the air is probably warmer so less heat would be required. 

[rt29781]

Hi, We have a solar store but as we only started the system in November we have no solar stored.  There is not enough sun at this time of year to keep heat in a store so the water gets heated by the evac tubes and transferred to the floor by a heat exchanger.  When we get a bit more sun the system will easily heat the house, the store  and then the pool.  After that  we will have an excess....Maybe we will heat the ground (via a loop) and get the heat back later...As we have only just installed the system it is difficult to know how many days a year we will really need the heat pump, so far only about 5 out of 30.  We have 2 Mitsubishi reversible units and they work fine but not when the temp. drops below 5C.  Air/Air heat pumps are no good when it is really cold they lose efficiency fast.  Hence the need to have a ground source heat pumps for the days when the sun don't shine and it is below 5C.  That varies each year and this year we have a lot of cloud at the moment.....Also the underfloor heating is so much better than the air blown heat pumps.  They give a warm head and cold feet which is not good.  So ideally we would always want the underfloor system, either powered by solar or ground source heat pump.  We have a computer hooked up to the solar controller so we are collecting data on what heat we can produce and as we go we can improve the system dynamics.