What is “One-way" communication?
One way communication means, that we can transmit commands to the HVAC system, and those should be executed accordingly. However, after the command is sent, we do not get any notification if it went through to actual execution. Also, if the status of the air conditioning unit was changed from another control source e.g. central controller, local wired remote, home automation, this info is not “pushed” back to us, and we won’t be aware of those changes. Same will happen in case of a malfunction or power loss when such information will not reach the user through this control type.
Briefly in summary: one-way communication gives us control but does not supply us with monitoring capabilities.
The most popular “one-way” communication control system is based on and utilizes IR (Infra Red) technology. The most common residential air conditioners use Infra Red wireless remotes for controlling the units as their main (and sometimes the only) control source.
What is “Two-way communication?"
As opposed to one-way communication,two-way communication means that we get both control and monitoring of the HVAC system. When using two-way communication, not only we get an “acknowledgment” that the command we sent has been received and executed properly, but we can also receive instant air conditioning system’s status at any given moment, including the following parameters: operation state (on/off), set point temperature, operation mode (cool/heat/fan/auto), fan speed or air conditioning status notifications such as: malfunction code, filter reset sign, room temperature, etc’. Any change in one of the air conditioning system’s parameters can be immediately reported, therefore enabling us to be in full command of the air conditioning system.
Why feedback is so important?
In the modern world, especially in the coming of the IoT (internet of things) era, every home appliance will most probably be operated by more than one control source, and this will also be the case with HVAC systems.
For instance, an air conditioning system that will have its own control (local, central or both), will require to be integrated in home automation scenarios, controlled remotely through the internet, and will also be connected to security systems and so on. Such a requirement can only be fulfilled if all control sources have direct two-way communication with the HVAC unit and can monitor its exact condition at any time point.
As an example, let us think of a situation, where there is a malfunction in the HVAC system. In this case, the malfunction code should be automatically fetched by the home automation system and passed on to the maintenance company, that can proceed for repair, requiring no involvement and report by the customer.
To summarize, an effective interaction of the HVAC system with the surrounding control platforms will always require full bi-directional communication, allowing the receiving of real-time feedback at any time point for properly arranged home operation scenarios.