For heat detectors on a 30° slope, spacing of detectors (excluding those at the very peak) is determined by which method?

For heat detectors on a 30° slope, spacing of detectors (excluding those at the very peak) is determined by which method?

• A. Use the floor-to-ceiling height
• B. Use the ceiling’s total height
• C. Use the average slope height
• D. Use the rise over run of the slope

Answer: (C)

When you’re placing heat detectors on a sloped surface, you need a measurement that reflects how tall the surface actually is along the incline. Using the average height of the slope gives a consistent basis for spacing from the lower edge to the upper edge, so detectors cover the entire slope evenly. If you used floor-to-ceiling height or the ceiling’s total height, you’d either underprotect the higher parts near the ridge or overprotect the lower parts near the eave because the height isn’t the same along the slope. The rise over run describes how steep the slope is, but it doesn’t directly translate into a practical spacing rule for protection along the slope. The average slope height effectively represents the vertical dimension over the length of the slope, making detector spacing appropriate for a 30° incline.

When you’re placing heat detectors on a sloped surface, you need a measurement that reflects how tall the surface actually is along the incline. Using the average height of the slope gives a consistent basis for spacing from the lower edge to the upper edge, so detectors cover the entire slope evenly. If you used floor-to-ceiling height or the ceiling’s total height, you’d either underprotect the higher parts near the ridge or overprotect the lower parts near the eave because the height isn’t the same along the slope. The rise over run describes how steep the slope is, but it doesn’t directly translate into a practical spacing rule for protection along the slope. The average slope height effectively represents the vertical dimension over the length of the slope, making detector spacing appropriate for a 30° incline.