# Operating temperature

## OAK4

OAK4 cameras (based on [RVC4](https://docs.luxonis.com/hardware/platform/rvc/rvc4.md)) are designed for industrial environments
with changing thermal conditions.
As described in the OAK4 climate/vibration testing blog, both
[OAK4-D](https://docs.luxonis.com/hardware/products/OAK%25204%2520D.md) and
[OAK4-S](https://docs.luxonis.com/hardware/products/OAK%25204%2520S.md) were validated in pre-production climate testing.

### Temperature Results

Across OAK4 climate validation, the following outcomes were reported:

 * Climate testing followed industrial environmental test methods (IEC 60068 family).
 * Performance remained stable during and after temperature variation testing.
 * Calibration remained stable, including after repeated disassembly/reassembly cycles.
 * No hardware degradation was observed during the validation campaign.
 * OAK4 operating range for full-system deployment is -20°C to +50°C.

Reports:

 * [OAK4-D temperature cycling testing
   report](https://drive.google.com/file/d/195wt0u2R5rle-Ufu_dPZ1ryIagKY_OR0/view?usp=drive_link)
 * [OAK4-D thermal shock testing report](https://drive.google.com/file/d/1pYRUpjdmGwiHzXATIdfQj1v6tD7TYub8/view?usp=drive_link)
 * [OAK4-S thermal testing](https://drive.google.com/file/d/1iLdSy4AEnKZzUiIMnWe-hN86k6PjFakC/view?usp=drive_link)
 * [OAK4-S thermal shock testing test](https://drive.google.com/file/d/1mjBSI-FFf_Zvx1f5rtpfxjwpzlLDrwNq/view?usp=drive_link)

## OAK

OAK devices, based on [RVC2](https://docs.luxonis.com/hardware/platform/rvc/rvc2.md), are rated for industrial use and have
operating temperature of -40°C to 105°C, while other components have a higher temperature range.

### Max temperature

In the general use case at a 25°C ambient, the chip running at full power (i.e. worst-case heat generation) resides at around 70°C
maximum, which sets the thermal margin to a minimum of 35°C.

Since devices generate about 45°C in worst-case, this means the maximum ambient temperature should theoretically be 60°C
(105°C-45°C=60°C).

#### OAK-D-Lite max temperature

As we wanted to make [OAK-D-Lite](https://docs.luxonis.com/hardware/products/OAK-D%2520Lite.md) as small as possible, we had to
use a smaller heatsink. This means the maximum ambient temperature is about 40°C.

| Test | Ambient [°C] | VPU [°C] | HS-CPU [°C] | HS [°C] |
| --- | --- | --- | --- | --- |
| Test 1 | 30 | 87 | 71.5 | 67 |
| Test 2 | 35 | 94 | 77 | 73 |
| Test 3 | 40 | 100 | 88 | 78 |
| Test 4 | 50 | / | / | / |
| Test 5 | 50 | 112 | 95 | 90 |

Legend:

 * Ambient temperature means the temperature of the air around the device
 * VPU is the temperature of the [RVC2](https://docs.luxonis.com/hardware/platform/rvc/rvc2.md) (as reported by depthai)
 * HS-CPU is the temperature of the enclosure where VPU is located
 * HS is the temperature of the enclosure on the opposite side of the VPU

Tests 1-4 were running all 3 cameras at 30FPS, stereo depth, NN (mobilenet), and video encoding, so the maximum workload possible.
As test 4 resulted in a crash of the device (at 125°C VPU temperature), test 5 was done without video encoding (only NN, stereo
depth, and 3 cameras at 30FPS).

### Min temperature

While the [RVC2](https://docs.luxonis.com/hardware/platform/rvc/rvc2.md) SoC has the lowest operating temperature of -40°C, we
have only tested our devices at the lowest ambient temperature of -25.1°C and they worked as expected. Minimum temperature would
depend on the computational workload, as the VPU would generate more heat when running at full power, which would heat up the
device.

Note that Pro versions ([OAK-D Pro](https://docs.luxonis.com/hardware/products/OAK-D%2520Pro.md), [OAK-D Pro
PoE](https://docs.luxonis.com/hardware/products/OAK-D%2520Pro%2520PoE.md)) have on-board IR laser dot projector that has an
operating temperature range of 10°C - 60°C (absolute limit 0°C - 80°C). If you would like to use Pro devices below 0°C, we would
suggest running the device (without projector) for a few minutes so the device heats up, which would also heat up the laser
projector, hopefully above 10°C.

### CCM heating

CCM (Compact Camera Module) are the modules that are integrated into the OAK cameras. OAK-D has 3 CCMs, 2x for stereo pair, and in
the middle is the RGB camera. CCMs themselves have different operating ranges and also some have lower thermal noise than others
(eg. on OAK Lite cameras, those CCMs have worse thermal noise).

We have done some quick testing on CCM heating with different sensors;
[IMX582](https://docs.luxonis.com/hardware/sensors/IMX582.md), [IMX214](https://docs.luxonis.com/hardware/sensors/IMX214.md),
[OV9282](https://docs.luxonis.com/hardware/sensors/OV9282.md), [IMX378](https://docs.luxonis.com/hardware/sensors/IMX378.md).

| Sensor | Max temp [°C] | Temp diff [°C] |
| --- | --- | --- |
| [IMX582](https://docs.luxonis.com/hardware/sensors/IMX582.md) | 64°C | 30°C |
| [IMX214](https://docs.luxonis.com/hardware/sensors/IMX214.md) | 62°C | 29°C |
| [OV9282](https://docs.luxonis.com/hardware/sensors/OV9282.md) | 50°C | 13°C |
| [IMX378](https://docs.luxonis.com/hardware/sensors/IMX378.md) | 46°C | 12°C |

Temp diff is the difference between the ambient temperature and the temperature of the CCM.

#### Command used for testing

We have tested thermals of our devices with max load, and you can achieve that by using the depthai_demo:

```bash
python3 depthai_demo.py -sub -lrc -rgbr 2160 --report cpu -enc color -encout /dev/null
```

This command has the maximum power consumption, therefore the devices have the highest heat output.

Note the framerate of the RGB camera is set to 30 (-rgbf 30). If it would be set any higher, it would be bottlenecked by the
neural network.

#### Results of our tests

All devices were tested in an ambient temperature of 18°C to 20°C.

Test on the [OAK-D-PCBA](https://shop.luxonis.com/products/bw10980bc) - rear thermal plate with black anodizing and Laird HD320
TIM:

 * Heatsink max temperature: 43°C
 * Die max temperature: 60°C

Test on the [OAK-1-PCBA](https://shop.luxonis.com/products/bw1093) with the Tianmai 6.5W/K TIM for both the front heatsink and the
MX. TMA-6518 (0.5mm) for the MX and the TMA-6500 (2mm) for the front were used. This test was with the BW machined heatsink.

 * Heatsink max temperature: 61°C
 * Die max temperature: 73°C

### Tests for OAK-1:

 1. 6535 back TIM only:
    
    * Die max temperature: 78°C
    * Rear heatsink max temperature: 62°C
    * Front heatsink max temperature: 60°C

 2. 6510 front + 6535 back TIM:
    
    * Die max temperature: 70°C
    * Rear heatsink max temperature: 59°C
    * Front heatsink max temperature: 60°C

 3. Test with T1 OAK-1 sample:
    
    * Rear heatsink max temperature: 61°C
    * Front heatsink max temperature: 63°C
    * Die max temperature: 73°C