Heating load credits refer to the reduction in heating load due to internal heat gains from sources such as solar radiation, people, lighting, and equipment. These credits are subtracted from the total heating load to determine the net heating load. However, it’s essential to note that these credits should only be taken if the building is specifically designed to utilize these heat gains, such as through passive solar design or high-efficiency lighting systems. Otherwise, these credits should not be applied to avoid oversizing the heating system.