What is the difference between a single-stage and a two-stage HVAC system?

A single-stage HVAC system indeed operates at one constant speed. This means that when the system is activated, it either runs at full capacity or is completely off. This can be less efficient in terms of energy usage because the system does not have the ability to adjust its output to match varying heating or cooling demands. In contrast, a two-stage system is designed to operate at two different speeds: low for maintaining comfort during mild weather, and high for extremely hot or cold conditions. This dual capacity allows the system to run more efficiently and maintain a more consistent temperature within the space being conditioned.

Understanding this distinction is crucial for making informed decisions regarding HVAC system selection and energy efficiency optimization.