Allmand’s indirect-fired heater, the Maxi-Heat, features twin heater units that produce a maximum of 1.01 million BTUs and clean, breathable air. A standard 1,800-rpm liquid-cooled Isuzu diesel engine with regulated generator provides power for the heaters and electrical accessories. The 191-gallon fuel tank provides more than 24 hours of operation without refueling. An in-line fuel heater and pre-filter on the fuel system makes the system more tolerant to dirt and variances in the viscosity of the fuel. The static pressure of the Maxi-Heat has increased from .5 inch of water gauge to 1.5 inch of water gauge. This has allowed Allmand to increase the length of the Maxi-Heat’s 16-inch ducting to 110 feet.