The weight is also a factor in the installation of luminaires. An electrician holding a luminaire overhead will encounter a more difficult installation process if the luminaire weighs more. A harder installation means that installation time will be longer for luminaires with heavy ballasts than for lighter weight luminaires. This translates directly into added cost of the installation. Since a magnetic ballast is an inductive device, power factor correction may be necessary.
Most fluorescent ballasts contain a capacitor integral to the ballast housing.
Other gaseous discharge ballasts employ a separate capacitor not integrated into the ballast. In either case, the added capacitance advances the phase angle of the current with respect to the voltage wave form, thus improving power factor. For a purely resistive load such as an incandescent lamp, the power factor is unity. Energy codes typically state that if the power factor is less than 0.80, then it must be corrected to at least 0.90. The energy that magnetic ballasts dissipate as heat represents an inefficiency in the system.