40K BTU FURNACE Suburban’s NT-30SP, NT-34SP and NT-40 are prime examples of the way powerful a compact ducted furnace can also be. Offered in quite a lot of capacities, as much as 40,000 BTU/h input, all of these 12-volt DC furnaces feature energy saving solid state electronic ignition. Cabinet size is similar on all models. (12 1/2″ x12″ x 23″) Their extremely low amp draw demands less out of your battery a definite plus for long trips! Gasket-sealed vent assemblies, steel gas manifolds, sealed forced-draft combustion, chrome-plated vent cap and wall thermostats are usual equipment. The P-30S and P40, essentially the most powerful furnaces within the RV industry as of late, are 115-volt park model furnaces, featuring long term heavy duty AC motors and AC controls.