A 50,000 BTU furnace and a 20,000 BTU water heater are located within an enclosure. Combustion air is provided through two horizontal ducts connecting to the outside. What is the minimum net free area required for each opening communicating directly to the outside?

A local exhaust system provided in the kitchen of a dwelling unit must have the capacity to exhaust a minimum air flow rate of ____ cfm intermittent or ____ cfm continuous.

Self-contained refrigeration systems are exempt from requiring a permit when containing ___ pounds of refrigerant or less or is actuated by a motor of ___ horsepower or less.

Grease ducts serving Type I hoods shall be constructed of steel having a minimum thickness of ____ inch.

1/2 inch steel gas piping shall be supported at intervals not exceeding ___ feet.

Fire dampers shall have a minimum fire protection rating of ____ hour when penetrating a 3-hour or greater fire-resistance-rated assembly.

The International Fuel Gas Code regulates piping systems for natural gas that have an operating pressure of ____ pounds per square inch gauge or less.

Given the appliance nameplate shown, the top of the instantaneous water heater shall have a minimum clearance of ____ inches to combustibles when installed outdoors.

The volumetric flow rate of gas provided to any appliance shall be adjusted for altitude when the installation is above ____ feet in elevation.

Sauna heaters must be equipped with a thermostat that limits the room temperature to no greater than ____.