The electric furnace, per vanilla, pollutes a little bit ( 0.9 pollution/second). Machines in Factorio pollute based on their energy usage (each machine has its own multiplier applied to energy use to arrive at pollution; this is why when you change a machine's energy use with modules its pollution changes too). Dirty Power increases the energy use of electric furnaces by 50% but reduces its multiplier by 1/8 so the furnace doesn't pollute quite 50% more than vanilla, but rather about 31% more (1.18125 instead of 0.9 ). I will probably change this in an update to be 33%, to keep the numbers cleaner (1.2 pollution/s) . While messing around with another mod I found a bug in the Dirty Power code that can cause crashes when certain thing change with recipes happen so I'll be updating soon anyway.
