The reason behind the fan speed of an air conditioner (AC) changing automatically when you press the channel up/down button on a television's (TV) remote control is likely due to a phenomenon called "interference."
Interference occurs when the signals from one remote control unintentionally affect another device. This phenomenon can happen because both TV remotes and AC remotes typically use infrared (IR) signals to communicate with their respective devices. When you press a button on the TV remote, it emits an IR signal to change the channel, adjust the volume, or perform other functions on the TV.
Now, if the AC's remote control operates on a similar or overlapping frequency range to that of the TV remote, there's a possibility that the IR signal from the TV remote might be detected by the AC unit's receiver as well. This can lead to unintended actions, such as changing the fan speed on the air conditioner.
It's essential to note that the occurrence of interference can depend on various factors, including the design and sensitivity of the AC unit's IR receiver, the specific frequency used by the remotes, and the distance and line of sight between the remotes and the devices they control. If the AC unit's IR receiver is particularly sensitive or the TV remote signal is strong enough, interference can happen more easily.
To prevent or minimize interference between different devices, manufacturers typically aim to use unique and specific IR frequencies for their products. However, in some cases, interference might still occur, especially with older or less advanced models of remote-controlled devices.
If you encounter interference between your TV remote and AC unit, there are a few things you can try to mitigate the issue:
Reposition the Devices: Adjust the positioning of your TV and AC unit so that their IR receivers face different directions, minimizing the chance of the signals overlapping.
Cover the IR Receiver: If possible, you can cover the IR receiver on the AC unit when you use the TV remote, and vice versa.
Use Universal Remotes: Universal remotes are designed to control multiple devices. Investing in a good-quality universal remote can help you avoid interference since it will have better control over the signals it emits.
Upgrade Devices: Consider upgrading your TV or AC unit to newer models that use more advanced remote control technology, which may be less susceptible to interference.
Always check the user manuals of your devices for information on remote control frequencies and any guidance provided by the manufacturer on avoiding interference.