Present a design for an IoT$-$enabled smart HVAC system for a large building. HVAC is Heating, Ventilation and Air Conditioning, and a smart version of this will collect data about room temperature, humidity and activity, control ventilation and air conditioning in the building.

In your design, you should use all three device categories:

$1.$ an end$-$user device

$2.$ a network device

$3.$ a cloud device

Create a high$-$level block diagram showing the different parts of the system and how they interconnect. Include the hardware list including the components and the communication technology you would use. Include the data design, what data is collected, and how it is stored e$.$g$.$ SQL tables or Documents from MongoDB. Describe your design and include diagrams to illustrate your design.