An entry-level HVAC technician assists their supervisors with the installation and repair of heating, air conditioning, and ventilation systems in residential and commercial buildings. You may provide support, such as preparing the tools and materials, documenting the services provided, and logging information in the company database. Once you are more comfortable with the process, your supervisor may ask you to be actively involved in the services, including installing a large air conditioning unit, repairing broken parts of current equipment, performing annual maintenance on a machine, or opening up and replacing ventilation lines. All HVAC technicians must follow the specifications outlined in blueprints or plans provided by designers or estimators.