HVAC integration - The past
When the first air conditioning systems came in, they were simple mechanical “machines”, with very few electrical components, just for making it work. There were no options for external control/integration. The only way of controlling them was by “cutting” off the HVAC unit power. Therefore, the only way to integrate HVAC systems was by adding a controllable (on/off) relay on the power supply line to the HVAC unit.
Later on, small split systems that entered the markets brought in a new control capability – the IR. Similar to TVs, Home Automation controllers “learned” the codes and started controlling those small split systems by their own IR transmitters, as an alternative to the original HVAC remote. Of course, it wasn’t ideal, since it was “one-way” integration, but it was much better than nothing those days.
The communicating thermostats that became very popular provided additional integration options, but they were mainly used as a stand alone solution.
HVAC integration - The present
Today, with the penetration of the inverter type HVAC systems to the world markets, the situation has dramatically changed: On one hand, the existing solutions (power line cut off and communicating thermostats) became irrelevant as an integration option (*the reasons will be explained in details in separate articles)
On the other hand, inverter operation requires much more complex control components, which also enable getting all control and monitoring relevant data via communication channels. This opens both a great opportunity and huge challenge for integration.
Opportunity – since all the data is “digitized”, as the different components in the HVAC system “communicate” via proprietary protocols, we should be able to access multiple system parameters and options such as: temperature sensor readings, operation status, operation mode, EV (electronic expansion valve) position, compressor status, etc.
Challenge – all this data is “internal”, inside the system, as those communication protocols are proprietary for each HVAC manufacturer, making them closed for 3rd party integration . In some cases, HVAC manufacturers provide “gateways”, but they fulfill the whole variety of requirements, coming from the “automation” side. There is no industry-wide standard for communication.
To summarize, along the history of HVAC systems, there have been multiple integration solutions:
- Dry contact – for on/off external input (usually without feedback).
- Original gateways provided by HVAC manufacturers (Usually Lon or BACNET)
- 3rd Party universal gateways
All the available solutions are brand and model dependent. Unfortunately, even today, there is no “universal” solution that will cover all brands and models.
And this is exactly where CoolAutomation’s products fit in.
Our approach was to create gateway solutions such as CoolMasterNet and CoolPlug, that can connect directly to the HVAC systems providing a very easy to implement, unified simple interface protocol on one side, that is flexible enough to accommodate the whole variety of integration demands on the other side.
HVAC integration - The Future
What does the future of HVAC integration hold? We can already see the trends today. Due to the IoT (Internet of Things) “hype”, HVAC manufacturers begin to equip their systems with Wi Fi capabilities, providing their own proprietary apps. We can assume that there would be more wireless solutions in this field. In addition to Wifi, other technologies, such as Zigbee, Z-wave, Bluetooth, etc. might be adopted. However, the HVAC manufacturers’ development efforts are oriented for “stand alone” control solutions, while integration with other systems is still not the highest priority for HVAC manufacturers.
However, once most of the HVAC units are equipped with wireless technologies, there surely would be solutions for wireless integration as well!