Fröling P4 Pellet Boiler in Connecticut Zero Energy Challenge Home By Travis PaigeSeptember 5, 2014January 10, 2022Fröling P4, Installations, P4 Pellet Boiler Installations, Stories The third place winner of the 2010 Connecticut Zero Energy Challenge has the Fröling P4 32/38 installed as its main heat source.Project datasheet link here.