How many spare fire sprinkler heads should be kept in a building with 313 installed sprinkler heads?

To determine the appropriate number of spare fire sprinkler heads to keep in a building, the guidelines from the National Fire Protection Association (NFPA) indicate that a specific percentage of the total number of installed sprinkler heads should be maintained as spares.

Typically, the recommendation is to have at least 6 spare heads for the first 100 installed heads, and then an additional head for every additional 100 heads. In this case, with 313 installed sprinkler heads, the calculation would be as follows:

• The first 100 heads require 6 spares.

• From 101 to 200 heads (an additional 100 heads), you would add 1 more spare.

• From 201 to 300 heads (another 100 heads), you would add another spare.

• For the remaining 13 heads (301 to 313), no additional spares are needed beyond what has been counted.

Putting it all together:

• 6 spares for the first 100 heads.

• 1 spare for the next 100 heads (101-200).

• 1 spare for the next 100 heads (201-300).

Adding these amounts together gives a total of 6 + 1 + 1 = 8 spares. Since