The Basics of HVAC

Using gas vs electric can be a tricky decision. Check your local utility rates as costs may vary.

While natural gas remains the most widely-used home heating fuel in the U.S., this type of fuel may not be available in all areas. Homeowners without access to natural gas lines or those who prefer a different type of home heating fuel may turn to electricity to power home heating systems. Despite its high efficiency, electric heating often costs more to operate than a traditional gas furnace. When comparing a gas furnace to an electric heater, consider not only the upfront and operating costs of each option, but also how these systems impact the environment. - sfgate.com

Read our guide on Natural Gas vs Electrification.

Packaged systems are simply central air conditioning systems. These have an exterior, combined condenser and evaporator, which are commonly used in North American buildings and homes. Packed systems elsewhere are typically used in large indoor spaces like stadiums, cinemas and convention centers.

Alternately, split systems consist of interior and exterior coils, which are preferred and used heavily outside of North America. Split systems in North America are most often seen in residential applications, but are beginning to gain popularity in small commercial applications, as well.

With split systems the evaporator coil is linked to a remote condenser unit that uses refrigerant lines between an indoor and outdoor unit rather than directly ducting air from the exterior unit. Split systems are often more efficient, and they take up less space, however, package systems can be far quieter, as the fan motor is outside.

The main advantages of mini-splits are their small size and flexibility for zoning and cooling individual rooms. Many models can have as many as four indoor air handling units (for four zones or rooms) connected to one outdoor unit. - energy.gov