GoggleboxUK wrote:Well temperature inside the greenhouse did eventually start to fall and the max/min inside the greenhouse read a high of 27.2 and a low of 8.9 so I assume that the heat sink eventually ran out of 'fuel'.
As Kristen says, ground source heating is a good method and the heatsink will benefit from the surrounding ground temps so I am hoping that won't ever fall below the 5c mark in winter and have a cooling effect in summer (although that's not important as I remove the panels).
I'm not really looking forward to colder weather or shorter days but I should be able to draw more conclusions once the conditions deteriorate, Over all things look promising at the moment.
I'm pretty certain that a heater will be required to keep above freezing during the coldest days and nights in mid winter. Saying that, you system will be cheap to run as its keeps the heat for so long following sunny days.