What is the main purpose of Solidworks?

Some of these puposes/benefits are:

1. Concurrent engineering (CE) – Engineering and manufacturing process are enabled simultaneously from shared Solidworks data.
2. Higher quality – Due to increased efficiency resulting from the ability to explore a greater number of design iterations during product development.
3. Lower unit costs – Due to reduced development and prototype expenses.
4. Rapid prototyping (RP) – Solidworks models can be used to produce prototypes from Stereolithography and other RP technologies.
5. Personnel development – Solidworks technology provides a challenging environment for employees.
6. Personnel advancement – A variety of positions regarding the management and supervision of Solidworks become available to advance employee careers.
7. Identify and eliminate inefficiencies – Solidworks develops opportunities for the elimination of inherent inefficiencies in existing work flows and/or practices.
8. Increased workload capacity – Efficient use of Solidworks allows the production of more work while maintaining current staff levels.
9. Greater feedback and control of production operations – Solidworks enables NC tool paths to be generated, updated, and verified automatically with little human intervention.
10. Improved overall communications – Solidworks enable a shift from the traditional paper based design and manufacturing system to a electronic paperless one.
11. Increased accuracy of MRP data – Solidworks data files can be easily linked and managed by MRP software.
12. Increased design flexibility – Solidworks offers a more robust set of tools and methods to modify designs.
13. Increased design data integrity – With a single Solidworks model supporting all downstream processes, changes are reflected quickly and accurately.

You could create a 3D CAD with 2D drawing functional not only for product design and HVAC system but you also can do the simulation for analysis purpose.

Solidworks main purpose to designa a Part and Assembly

The main purpose of Solidworks and for that matter, any 3-D Modeling Computer Aided Design and Analysis software is prototyping without risk. A system can be designed, analyzed and simulated in a safe, non-destructive and real-time environment

Solidworks is a solid modeling computer-aided design (CAD) and computer-aided engineering (CAE) computer program that runs on Microsoft Windows.

Again a very nice and detailed answer... (y)