an insulated chamber comprising an air intake, an emissions intake, and an exhaust, the emissions intake for receiving exhaust gas and waste products emitted as a result of fuel combustion and the exhaust for discharging remaining emissions from the insulated chamber, the insulated chamber having a bottom surface over which residual water accumulates from a mist therein;

a primary heat recovery exchanger containing a fluid therein, the primary heat recovery exchanger contained within the insulated chamber for contacting a mixture comprising air introduced via the air intake and exhaust gas and waste products introduced via the emissions intake such that heat exchange is effectuated with the fluid;

a fluid circuit comprising a primary conduit in fluid communication with the primary heat recovery exchanger;

a heat extraction exchanger in fluid communication with the primary heat recovery exchanger via the fluid circuit and for effectuating heat exchange with an airstream running therethrough; and

a secondary heat recovery exchanger within the insulated chamber in fluid communication with the primary heat recovery exchanger, the secondary heat recovery exchanger extending over the bottom surface of the insulated chamber and configured to remain at least partially covered by the accumulated residual water.