Cell of Interest

Cell of Interest (COI) is a location on a building which corresponds to some form of interaction between the building and the world. There are three types which are: material delivery, material drop-off, and Dupe interaction. In most cases, the three types of COI are located in the same location. It's known as Tile Of Interest (TOI) by the community but should be named Cell of Interest because the location is a cell, not a tile.

Cell of interest type

• Delivery cell - The cell which accepts item deliveries to the building.
• Material drop-off cell - The cell where the building item output is dropped, e.g food from an electric grill.
• Dupe interaction cell - The cell that the Dupes must occupy in order to operate the building. Dupes exist in the bottom cell for most purposes.

List of buildings' Cell of interest

• Algae Distiller: Delivery and material drop-off at the middle bottom cell
• Apothecary: Delivery, Dupe interaction and drop-off all at the bottom left cell.
• Arcade Cabinet: Dupe interaction on either bottom left or right cell, both can be used at the same time.
• Blastshot Maker: Dupe interaction at bottom middle cell. Material drop-off at bottom fourth tile from the left.
• Bleach Stone Hopper: Delivery at middle bottom cell. Outputs are ejected from the Squeaky Puft-shaped portion of the machine, located roughly at the upper right corner of the middle cell. The outputs will eject at a diagonal angle with a small amount of variance simultaneously towards both the left and right, usually landing in an area consisting of the bottom left cell, one cell to the left of the machine, and the two cells to the right.
• Botanical Analyzer: Delivery and Dupe interaction at middle bottom cell. Material drop-off at far left bottom cell.
• Bottle Emptier: Liquid output at adjacent bottom cell, facing the faucet.
• Clothing Refashionator: Delivery, Dupe interaction and drop-off at middle left bottom cell.
• Coal Generator: Delivery at bottom middle cell.
• Comfy Bed: Dupe interaction at the middle left bottom cell.
• Compost: Delivery and Dupe interaction at the bottom left cell. Material drop-off at the bottom RIGHT cell, despite the animation visibly showing the middle.
• Conveyor Loader: Delivery at the conveyor output cell (the one with the crate).
• Conveyor Receptacle: Pick up at the conveyor input cell (the one at the fat end).
• Cot: Dupe interaction at the bottom left cell.
• Critter Feeder: Bottom cell.
• Crops: Harvest at Plant's bottom cell. Delivery at Planter Box or Farm Tile. The same is true for natural growing plants.
• Desalinator: Dupe interaction and material drop-off at the middle left bottom cell (you need to empty this one manually, maximum ~950kg).
• Dehydrator: Dupe interaction, material delivery, and dried food and water drop-off at the middle bottom cell.
• Egg Cracker: Delivery and Dupe interaction at the bottom left cell. Material drop-off at bottom right cell.
• Electric Grill: Delivery, Dupe interaction material output at middle bottom cell.
• Espresso Machine: Delivery and Dupe interaction at middle bottom cell.
• Ethanol Distiller: Delivery and Gas output at the middle left bottom cell. Material drop-off at the rightmost bottom cell.
• Exosuit Forge: Delivery, Dupe interaction and drop-off at middle left bottom cell.
• Farm Station: Delivery, Dupe interaction and drop-off at bottom left cell.
• Fertilizer Synthesizer: Deliver and material drop-off at the middle left bottom cell.
• Fish Feeder: Bottom cell (fish symbol cell).
• Gas Range: Delivery, Dupe interaction material output at middle bottom cell.
• Geotuner: Middle left bottom cell.
• Geyser, Volcano, or Vent: While each of these material-outputting formations have different sizes, the cells of interest are consistent with the four tiles of Neutronium that are spawned underneath them. Dupe interaction is one cell above the center-left tile of Neutronium, and material output is two cells above the center-left tile of Neutronium.
• Glass Forge: Delivery and Dupe interaction at the bottom middle cell.
• Grooming Station: Dupe interaction at bottom left, critter interaction at bottom cell.
• Hydrogen Generator: Dupe interaction at bottom right cell.
• Ice-E Fan: Delivery and Dupe interaction at bottom left cell, animation looks off.
• Incubator: Delivery, Dupe interaction, eggshell drop all at the bottom left cell.
• Juicer: Delivery and Dupe interaction at the bottom middle cell.
• Jukebot: Dupe interaction on either bottom cell (don't know about the middle).
• Kiln: Delivery and drop-off at the bottom left cell.
• Lavatory: Dupe interaction at the bottom left cell.
• Manual Generator: Dupe interaction at bottom left cell.
• Materials Study Terminal: Dupe interaction at bottom middle cell.
• Massage Table: Dupe interaction at the bottom left cell.
• Mess Table: Dupe interaction at bottom cell.
• Metal Refinery: Delivery and Dupe interaction at the bottom middle cell. Material drop-off at the bottom right cell.
• Microbe Musher: Delivery, Dupe interaction, material output at bottom left cell.
• Molecular Forge: Delivery, Dupe interaction and drop-off all at the middle left bottom cell.
• Natural Gas Generator: Liquid output at middle right bottom cell.
• Observatory: Dupe interaction at middle left bottom cell.
• Oil Refinery: Dupe interaction at the middle left bottom cell (animation is off again).
• Oil Well: Liquid output at rightmost bottom cell, gas output at middle left bottom cell.
• Ore Scrubber: Dupe interaction at bottom middle cell.
• Outhouse: Delivery, Dupe interaction, material drop, Morb spawn- all at the bottom left cell.
• Oxylite Refinery: Delivery and drop-off at the bottom middle cell.
• Petroleum Generator: Liquid output at rightmost bottom cell. Gas output at the middle top cell.
• Polymer Press: Material drop-off at the bottom left cell. If it's flipped, material drop of is one cell outside of its building area.
• Power Control Station: Delivery, Dupe interaction and drop-off at bottom left cell.
• Printing Pod: Drop-off on either middle cells. Don't know if this means that a sweeper need to be able to reach both. Weight plate gives no signal.
• Ration Box: Bottom left cell.
• Refrigerator: Bottom cell.
• Research Station: Delivery and Dupe interaction at bottom left cell.
• Rock Crusher: Delivery, Dupe interaction, drop-off - all at the middle left bottom cell. Dupe animation looks like it's in the right most cell, don't be fooled.
• Rust Deoxidizer: Bottom left cell.
• Shearing Station: Dupe and critter interaction at middle bottom cell. Material drop-off is at the bottom left cell, but with enough variance that it is possible for the debris to occasionally land on the cell to the left or right of the bottom left.
• Shower: Dupe interaction at the bottom left cell.
• Sink: Dupe interaction at the bottom left cell.
• Skill Scrubber: Middle bottom cell.
• Sludge Press: Dupe interaction and drop-off at middle left bottom cell.
• Soda Fountain: Dupe interaction at bottom left cell.
• Spice Grinder: Delivery, Dupe interaction, and Drop-off at left bottom cell.
• Storage Bin: Delivery at bottom cell.
• Storage Tile: Delivery at the single cell it occupies. Be aware that as a solid tile, the possible angles that duplicants and auto-sweepers can access it from may vary, relative to a storage bin.
• Sublimation Station: Delivery at left cell.
• Super Computer: Dupe interaction at bottom middle cell.
• Telescope: Dupe interaction is at the 2nd tile from the bottom left.
• Textile Loom: Delivery, Dupe interaction and drop-off at middle left bottom cell.
• Triage Cot: Patient and Nurse both on the bottom middle cell.
• Virtual Planetarium: Dupe interact at the middle left bottom cell.
• Wash Basin: Dupe interaction at the bottom left cell.
• Water Cooler: Dupe interaction on either bottom left or right cell, depending on which direction they came from.
• Water Sieve: Delivery and material drop-off at the middle left bottom cell. If you flip the Water Sieve it's the bottom right cell, it's always the middle cell closest to the automation port (or opposite to the lamp).
• Wood Burner: Delivery at bottom left cell.

Reference

• https://www.reddit.com/r/Oxygennotincluded/comments/d7syf4/buildings_tiles_of_interest_almost_complete_list/