Electric furnace array that is only 11** tiles wide, meaning it can fit in the same space (in width) as the typical beginning/midgame stone/steel furnace arrays, and it's as short as possible. Gallery here: https://imgur.com/a/1D51F
** To get it to tile beside itself, I had to create A/B versions that are mirrored to fit power, which otherwise stick out one tile. This is tileable and expandable lengthwise as well (in groups of 4 furnaces).
In the blueprint book you'll find mirrored A and B versions of the electric furnace array to tile them next to each other, as well as an example steel furnace array that uses red/yellow belt weaving to fully compress a red belt (since the underground trick is gone in 0.16). All the arrays can consume and completely compress a red belt with any 1:1 smelting recipe.
There is plenty of spare belt capacity, making it very easy to increase capacity by just making it longer. To consume/output a blue belt, just add 6 tiling groups (24 furnaces) and switch to blue splitters at the ends. Once 0.16 can compress via sideload, it should even be able to support close to 2 red belts by doubling the length.
The pattern completely fills the space (0 gaps on the interior), and it similar in layout (despite the craziness) to the steel furnace array, is mostly symmetrical and tileable, and it does a good job at compression. These features make it pretty neat, and it looks awesome in normal and map modes in my opinion. But to be perfectly honest this is a fairly expensive design, with many undergrounds and a lot of substations. :)