Ventilation System

Ventilation

50%

HomeKit doesn’t support ventilation system by default but instead offers fans.

Fans can be turned on and off very easily by tapping on them in the Home app. You can set a specific fan level in the detail screen of the accessory. The characteristic “Fan Level” supports the following data types.

• DPST-5-1 (0…100%) sends values between 0% and 100%.
• DPST-5-10 (0…100) sends values between 0 and 100.
• DPST-5-10 (0…255) sends values between 0 and 255.
• DPST-5-10 (0…4) sends the values 0, 1, 2, 3 and 4
• DPST-5-10 (0…3) sends the values 0, 1, 2, and 3
• DPST-5-10 (0…2) sends the values 0, 1, and 2

If your KNX-enabled ventilation system supports value range of 0-100, you have to select the correct data type. Because the encoding of DPST-5-1 (5.001) and DPST-5-10 (5.010) is different.

No matter what fan level you choose in hkknx, the Apple Home app always shows a value between 0-100%. The conversion between the HomeKit and KNX values is automatically done by hkkknx.

For example, the conversion for data type DPST-5-10 (0…2) is as follows.

• 0% → 0
• 50% → 1
• 100% → 2