A continuation of MoreFurnaces by Cubex2, maintained by the Nomifactory Dev team.
Intended for use with Nomifactory, but of course everyone is welcome to use it.
This mod adds multiple tiers of furnaces: Iron, Copper, Silver, Gold, Diamond, Obsidian, and Netherrack. These furnaces are faster and more efficient than vanilla furnaces, and gain additional benefits like multiple input and output slots, or even parallel processing.
While not used in Nomifactory, there are also upgrades that can be used to improve the tier of a furnace in-place rather than breaking it and using it in the crafting table.