True or False: Retrofitting to energy efficient lighting increases the heating load?

• A. True
• B. False
• C. Depends on fixture type
• D. Not enough information

Answer: (A)

Internal heat gains from lighting affect how much heating a building needs. Traditional incandescent fixtures release a lot of energy as heat, which adds to the space’s warmth. When you retrofit to energy-efficient lighting, the amount of heat produced by the lights drops. In a heating-dominated scenario, that reduction in internal heat means the heating system has to supply more heat to reach the same comfort level, effectively increasing the heating load. This is especially noticeable in winter or in well-insulated spaces where little external heat is gained. In hot seasons, the reduced heat from efficient lighting would help lower cooling load, but the statement about heating load specifically is true.