What is the voltage standard for residential HVAC systems in the United States?

The voltage standard for residential HVAC systems in the United States is 120/240 volts. This standard is designed to meet the requirements of typical household appliances, lighting, and heating and cooling systems.

In residential settings, 120 volts is commonly used for light fixtures and standard household outlets, while 240 volts is typically used for larger appliances like air conditioners, electric furnaces, and water heaters, which require more power to operate efficiently. The use of a split-phase electrical system allows for the distribution of both voltage levels from a single service entry, making it versatile for various household needs.

The other voltages mentioned, such as 100/200 volts, are not standard in residential applications in the U.S. 240/480 volts is more typical in commercial or industrial settings where higher power demands are common. Similarly, 380/415 volts is used in European countries and is not applicable to U.S. residential systems. Thus, 120/240 volts is the correct answer, reflecting the established voltages that residential HVAC systems rely on.