Referencing your Condensing Boiler's Efficiency: Which of the following elements needs to be included when calculating the Boiler's Seasonal Efficiency? Select one or more: a. Total of all Energy Consumption Heating Load Calculations, i.e. Conductive Losses, Infiltration Loss, & Ventilation Losses. b. Annual Fuel Usage Information (AFUE) information for the boiler or furnace from Department of Energy c. Heating Degree Day (HDD) Data from the past Heating Season from DegreeDays.net. This total varies from Heating Season to Heating Season depending on the severity or mildness of the Heating Season. d. Total of all Design Heating Load Calculations, i.e. Conductive Losses, Infiltration Loss, & Ventilation Losses. (qtotal = qcond + qAL + qvent) e. Quantity of Fossil Fuel consumed over the past Heating Season. (Q Total Consumed = Q/Unit of Fuel.* *# of Units of Fuel)