Final answer:
The indoor combustion air supply required according to the "Standard Method" is not directly answered by the reference provided, as it may vary and is typically found in HVAC codes or design references.
Step-by-step explanation:
The question pertains to the indoor combustion air supply required for heating equipment using the "Standard Method." This is often related to heating, ventilation, and air conditioning (HVAC) engineering principles. According to many building codes and the International Fuel Gas Code, an indoor appliance requires a certain amount of combustion air based on the appliance's input rating in British Thermal Units (BTUs). Although the specific code requirements may vary, a common standard is to provide 50 cubic feet of indoor space per 1,000 BTU/h of the appliance rating for combustion and dilution air.
Therefore, the answer to the question is not provided directly in the reference information given, as these figures typically come from code books or specific HVAC design references. However, based on the question options, it's essential to know that the calculation is generally more complex and dependent on other factors such as the type and efficiency of the heating equipment, whether the air is provided mechanically or naturally, and tightness of the building envelope.