Your engine is supplying the FDC at a high-rise building with dual 3" lines, at 100% length. What is the friction loss for four standard CFEMS high-rise packs on the 8th floor?

To determine the friction loss for the four standard CFEMS high-rise packs on the 8th floor, we need to consider the friction loss per 100 feet of a 3-inch hose as well as the distance involved. Typically, when calculating friction loss for hose lines, references such as the NFPA or similar guidelines provide the standard friction loss values.

For a 3-inch line, the friction loss is typically around 5 psi per 100 feet. Given that you are operating on the 8th floor, you need to establish how many feet of hose would be deployed. In high-rise firefighting scenarios, it is common to see the height of each floor at approximately 10 feet. Therefore, for 8 floors, the total height is approximately 80 feet.

To calculate the friction loss, you would first convert the vertical distance into hundreds of feet since friction loss is calculated per 100 feet. In this case, 80 feet is 0.8 of 100 feet.

Next, compute the friction loss for just one line:

• Friction loss for the first line is: 5 psi (per 100 feet) * 0.8 = 4 psi.

Since you have four high-rise