question 20 of 119\nwhat is the minimum cross - sectional area of the flue for a 14 - foot - tall fireplace…

question 20 of 119\nwhat is the minimum cross - sectional area of the flue for a 14 - foot - tall fireplace with an opening 20 inches x 24 inches?\na. 40 sq in\nb. 50 sq in\nc. 60 sq in\nd. 80 sq in

question 20 of 119\nwhat is the minimum cross - sectional area of the flue for a 14 - foot - tall fireplace with an opening 20 inches x 24 inches?\na. 40 sq in\nb. 50 sq in\nc. 60 sq in\nd. 80 sq in

Answer

Explanation:

Step1: Recall the rule for flue - cross sectional area

For a fireplace, the minimum cross - sectional area of the flue is typically 1/10 of the fireplace opening area.

Step2: Calculate the fireplace opening area

The fireplace opening has dimensions 20 inches×24 inches. The area of the fireplace opening $A_{opening}=20\times24 = 480$ square inches.

Step3: Calculate the minimum flue cross - sectional area

The minimum cross - sectional area of the flue $A_{flue}=\frac{1}{10}\times A_{opening}$. Substitute $A_{opening}=480$ square inches into the formula, we get $A_{flue}=\frac{1}{10}\times480 = 48$ square inches. Since we need to choose the closest value greater than or equal to 48 square inches from the options, the closest value is 50 square inches.

Answer:

B. 50 sq in