Sealed combustion, gown flow 80% Gas Furnace. The DG Series Gas Furnace is actually two systems in one. As a powerful air handler, it can handle up to 4 tons of cooling. Additional blower accessories will provide 5 tons of cooling. As a Gas Furnace, its range of heating capacities makes it a perfect match for the heating requirements of almost any manufactured home. All of our DGAA furnaces have the same blower assembly regardless BTU. The airflow chart can be found in the tech guide and shows the cfm at a given supply static pressure which should not exceed 0.3 in WC. Therefore they do up to 4 ton ac and about 3.5 ton hp airflow. It is figured on 350/360 cfm per ton. There is a 5 ton ac/4 ton hp blower assembly accessory that can be installed. We do not support the 5 ton heat pump in manufactured housing because the pumps need more airflow and you usually cannot get enough with the MH ductwork like it is.