Tealights and terracotta pots

[Containergardener]

Anyone use these or tried them to add some warmth to the greenhouse?

[Mr Bones]

They do make a difference but can only kick out the heat from the candle that's inside them - they can't increase the heat output of the candle - if that makes sense.

[Containergardener]

I understand that . Wondered if it was worth trying. How much difference it would make ?

[quanglewangle]

Based on measurements of a taper-type, paraffin wax candle, a modern candle typically burns at a steady rate of about 0.1 g/min, releasing heat at roughly 80 W.

From wikipedia Candle entry.

More than I thought, actually.

But I would think a bigger effect might be from the air movement caused by convention. Its why they light bonfires in vineyards - not that they expect a puny fire to warm the whole vineyard, but the convection currents will get the air moving and stop frost forming