Welcome to Category C, where technology stops being just a saving mechanism and turns into the ultimate orchestrator of your daily comfort (Comfort).
The biggest energy load—but also the most critical system for your well-being inside the building—is air conditioning (Cooling/Heating). Whether we are talking about an old 15-year-old split room air conditioner, or a state-of-the-art air-to-water Heat Pump, the goal of Smart Home is to control them remotely and integrate them into automation.
As engineers, we divide air conditioning control into three different levels, depending on your budget and the capabilities of your machinery. Let's see how we go from the cheap "illusion" of control to ultimate, two-way communication.
This is the most well-known and economical solution (cost around €15 - €30) to make any old wall air conditioner "smart", as long as it works with an infrared remote control.
You buy a small device (eg Broadlink RM4, Sensibo, SwitchBot Hub) and put it on a shelf, opposite the air conditioner. You connect it to your Wi-Fi. This device "duplicates" (clones) the signals of your original remote control. When you press "22°C Cooling" on your mobile, the device emits an infrared signal and the air conditioner thinks you pressed the physical remote control.
Infrared (IR) technology is "one way". If you turn on the A/C from the mobile, but then your roommate comes and turns it off with the physical remote, the app on your mobile will still show that the machine is working! Your Smart Hub is "blind" to the actual state of the device.
All modern air conditioners are now sold "Wi-Fi Ready" or have built-in Wi-Fi. They use applications from the manufacturers (eg Daikin Onecta, Midea SmartHome, Gree+).
The device connects directly to your Router. The communication takes place through the Cloud Servers of each company.
This is where the IR problem is solved. The air conditioner "talks" to the app. If you change the temperature with the physical remote control, the reading on your mobile will be updated immediately.
You can connect these Cloud accounts to Google Home or Alexa for voice control. If you have Home Assistant, you can pull the manufacturer's API and put the A/C into your scripts (eg "Turn on the Midea when I open the door").
When we move to centralized systems (Heat Pumps, Fan Coils, VRV/VRF systems), the infrared remote control is often absent. There, the control must be wired (Hardwired), through the central board of the machine.
The simplest industrial way is to use dry contacts (Dry Contacts).
The heat pump board has special terminals. If you short-circuit these terminals (with the help of a smart relay, eg Shelly Plus 1), the machine turns on. If you open the circuit, it goes out.
It is the ultimate, foolproof method for On/Off control. Mostly used in hotels (when you take the card out of the slot, a relay cuts the dry contact and the A/C turns off instantly).
But what if you don't just want to "On/Off" the Heat Pump, but want to change the water temperature, read the Error Code if it breaks, or drop the Inverter power to 50% because the Peak Shaving system requires it? This is where we need digital chat.
Modbus/BACnet: As we mentioned in BMS systems, it is the language of machines. By using special Gateways (such as Intesis products), your air conditioner is connected by cable to the Smart Home's brain. The system accesses the deepest parameters of the manufacturer's board. KNX integration: If you have built your house with KNX wiring (as we saw in Class A), you add a "KNX-to-AC Gateway" accessory (eg from Zennio). The Magic Result: The elegant glass KNX switch you have on the wall of your living room (which controls the lights and blinds), now also has a thermostat display that controls the Daikin/Mitsubishi heat pump, without having to have the manufacturer's ugly plastic control on the wall!
Where do thermostats like Google Nest or tado° stack up in this category? They act as the perfect "bridge" for home users. They replace the old wall thermostat (which often uses dry contacts or OpenTherm protocol with the gas boiler) and at the same time have excellent mobile applications. They offer the level of control of Modbus, but with the friendliness of Wi-Fi (and the PID algorithms we discussed in a previous chapter).
Choosing the right control level depends on your equipment:
Next Step: We've adjusted the air temperature, but what about the main source of heat (and heat) coming into our home? The Sun.
Moving on to the next critical guide for your comfort: Electric Roller Blinds & Awnings: 4 Wire Motor Wiring (Standard) with Smart Shade Switches and Limit Calibration.
Return to category.
Go to categoryReturn to the central guide.
Go to guide
