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An air-cooling machine that fits into a wall. Cool air comes out one side, while hot exhaust comes out the other. Can be used to cool down rooms during summer, or to create a walk-in freezer.

Base Stats

Market Value
275 Silver.png [Note]
1 ˣ 3


Skill Required
Construction 5
Work To Make
1,600 ticks (26.67 secs)
Resources to make
Steel.png 90 + Component.png 3
Deconstruct yield
Steel 68 + Component 2

The cooler is a device that can be used to lower the temperature in a room by moving the heat to its other side. This effect can maintain happy colonists during high outdoor temperatures, prevent heat stroke and prevent perishable items like food from spoiling. It requires power to operate.


Perishable items will spoil if not covered or kept cool. The cooler the temperature at which they are kept, the longer they will last. Once the temperature reaches the freezing point of water (0ºC / 32ºF), they will freeze and no longer spoil. If you can maintain this low temperature, then your perishable items can be stored indefinitely.

Coolers can help beyond maintaining a pleasant room temperature for colonists. By setting the thermostat of a cooler to maintain a room temperature below freezing, you can create a "walk-in freezer". Perishable items stored in this room become frozen and no longer susceptible to spoilage. In many warmer biomes, spoilage is a major obstacle in maintaining a food supply, and thus freezer construction is generally considered a high priority.

Note that items inside will begin spoiling once warmer than 0ºC / 32ºF. It's generally a good idea to set a cooler a few degrees below 0ºC / 32ºF to keep a slight buffer against temperature gains from opening doors, cooler breakdowns, power outages, etc. Constructing an air lock is a good idea in warmer climates.


Coolers use power and take the place of a wall tile. Make sure that they are oriented properly when placing so that their blue square points into the room to cool. If powered and the room is enclosed with a complete roof and the entrance or exit of the cooler are not blocked via walls built later, it will begin to cool.

Coolers work by removing heat out of a room and placing it on their red tile side. This heat can be harnessed for use if desired, such as heating up living spaces in a base in a 'cold but not quite freezing' biome.

Coolers require no specific placement within a given wall. A cooler in one wall of a room will cool the space as efficiently as a cooler on the other side of the same room.


If the areas surrounding a room are hotter than the current temperature inside that room, heat will penetrate back into the room. As a result, the overall area of the room as well as the number of coolers affects how easy or difficult it is to cool a room. A single cooler has a maximum efficiency and may not be able to reach the target temperature of its thermostat if the room is too hot or too large. In these situations, building multiple coolers is helpful, but it consumes more power.

Coolers have two states of power consumption: low and high. A cooler that is actively cooling a room will consume 200W (high power) regardless of the thermostat setting. Once the goal temperature is reached, the cooler will transition to its low power state where it only uses 20W. However, if the exterior of the room is warmer, the instant the goal temperature is reached, heat will penetrate the room, the cooler senses this and returns to the high power state (there is a time buffer to this effect to avoid a flickering between high and low power states). This low power state can be exploited to save power when using multiple coolers to cool a large room. Consider stepping down each cooler one degree below each other for this room. That way, only one or two coolers will be active in their high power state maintaining the temperature of the room, while the others remain in their low power states, only to be used during times of higher temperatures, such as daytime or heat waves.

Simple playtesting reveals that with an exterior temperature of 27-38°C(80-100°F), a single cooler can cool a room with a 10x10 exterior to a minimum temperature of 10-16°C (50-60ºF). Under these conditions, 2-3 coolers were required to maintain a constant (frozen) 0-Negative 1°C (30-31°F) within the same space. Further testing (or evaluation of the source code) could be used to determine an exact formula for cooler performance and temperature gradient speeds.

Further test results:

Outdoor temp: 46°C

Room size (inside): 5x5

(outside): 6x6

Cooler: 1

Temperature: -2°C - -3°C

Outdoor temp: 46°C

Room size (inside): 5x5

(outside double walls) :7x7

Cooler: 1

Temperature: -12°C - -14°C

Note: The 4 outer corner nor the 4 inner corner walls seem to matter. The material doesn´t seem to matter either.

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