These items play a very important role as well compared to the main equipment. Typical items include; thermostats, humidifier, air cleaners and uv lights. Items are not just limited to these but these are the typical items found with your system. Not only do these items bring more comfort to your home, but also helps save you money by saving energy.
Think of it as the translator between you and your equipment, you tell these items what you want from it, and it tells your equipment in their own digital language to provide you want you ask for.