I have been using two Helvetic Sunjoy panels fore two years now,one in a new room that was add to the house. This is the only heating in the room. Before I use the room I switch the panel on approx 15 minutes and then the room would be nice and warm. The other panel is fixed to the wall in my conservatory and because of the Helvetic panel I use in the winter time. I am very pleased with the panels and electricity consumption.