Layout requirements for hotel indoor hydrant systems: spacing, protection radius, fire nozzle solid water column
I am Daniel Wang, a water supply and drainage specialist. The layout of the hotel's indoor fire hydrant system is a core part of fire water system design, directly related to the effectiveness of initial fire suppression and the safety of personnel evacuation. Based on my more than 20 years of engineering experience, hotels, as high-occupancy premises, must have their fire hydrant layout strictly comply with codes while also balancing aesthetics and practicality.
Detailed Layout Requirements
1. Fire hydrant spacing
According to Article 7.4.6 of the "Technical Code for Fire Water Supply and Hydrant Systems"(GB 50974-2014), the layout spacing of indoor fire hydrants shall be determined by calculation, but for high-rise hotels (building height greater than 27 m) it shall not exceed 30 m, and for multi-storey hotels (building height ≤ 27 m) it shall not exceed 50 m. In an actual project, I participated in the design of a five-star hotel (building height 45 m), using 25 m spacing to ensure that any fire point is covered by two water nozzles simultaneously. Note that fire hydrants in hotel guest room corridors should avoid decorative partitions to facilitate quick access.
2. Protection radius
The fire hydrant protection radius is calculated according to the formula R = Ld + Ls, where Ld is the hose length (usually 25 m), and Ls is the horizontal projection of the water nozzle's compact water jet. According to Article 7.4.12 of GB 50974-2014, the compact water jet length shall not be less than 13 m (hotels are high-rise buildings or high-occupancy premises). Taking a water nozzle elevation angle of 45° as an example, the horizontal projection is about 9.2 m (13 m × cos45°), so the protection radius R ≈ 25 + 9.2 = 34.2 m. However, the code requires spacing not to exceed 30 m; in practice I often control it at 30 m to ensure redundancy.
3. Water nozzle compact water jet
Article 7.4.12 of GB 50974-2014 clearly specifies: the compact water jet of water nozzles in high-rise hotels shall not be less than 13 m; for multi-storey hotels, if the volume is > 5000 m³, it shall also not be less than 13 m. This is because the fire source in hotel guest room areas may be near the ceiling (such as electrical fires), and a 13 m water jet can effectively strike the base of the flame. I once handled a case: a hotel lobby had a storey height of 8 m, and the original design water jet was only 10 m. During acceptance, it was found that it could not cover the ceiling area, so it was adjusted to 13 m and pressure-reducing orifice plates were added to ensure pressure and flow.
Actual Engineering Case
In 2019, I was responsible for the fire system optimization of a resort hotel (10 storeys, building height 36 m). The original design fire hydrant spacing was 35 m, but calculation showed that the protection radius at the corridor end was insufficient. In accordance with Article 7.4.6 of GB 50974-2014, we reduced the spacing to 28 m and added fire hydrants in each stairwell to ensure dual water nozzle protection. At the same time, the water nozzle compact water jet was configured at 13 m, using DN65 fire hydrants and 19 mm nozzle water nozzles. On-site testing showed that the compact water jet reached 14.5 m, meeting the requirements.
Summary
The layout of the hotel indoor fire hydrant system should be based on codes and combined with the building plan and functional zoning. Spacing should preferably be controlled at 25–30 m, the protection radius should be ensured by calculation to provide coverage, and the water nozzle compact water jet should not be less than 13 m. In actual construction, pipeline pressure balance and aesthetics (such as recessed installation) also need to be considered. The above are reference opinions. The actual project situation still needs to be further comprehensively evaluated and implemented in combination with specific working conditions, site conditions and other factors.