About Fire Sprinkler Heads
Automatic fire sprinkler heads are widely used in residential and commercial settings for fire prevention purposes, including apartment buildings, warehouses, offices and many others. To properly size/select an appropriate sprinkler head, it is necessary to become familiar with the subject terminology as explained below:
Standard vs Concealed Sprinkler Design
Standard fire sprinkler heads are mounted fully exposed to the indoor environment, with no additional covers (except for optional guard cage). This option is designed mostly for applications where functionality comes before looks, such as in production facilities, commercial storage spaces, warehouses, garages, etc.
Concealed fire sprinkler heads are designed primarily for use in homes & apartment buildings, where functionality and looks must be balanced. Concealed design allows the sprinkler head to be recessed in the ceiling and adjusted for flush fit. This, in turn, prevents accidental damage to the sprinkler and eliminates the need for a cage guard.
Difference between Pendent, Upright and Sidewall/Horizontal fire sprinklers
The only difference between these 3 types listed is in the mounting -
Pendent sprinkler heads are mounted vertically, pointing down from the ceiling, so that when activated, the deflector plate allows water dispersion down and to the sides;
Upright heads are mounted vertically, pointing up towards the ceiling, and when activated, will disperse water up, to the sides and then down;
Horizontal or Sidewall heads are wall-mounted and when activated, will deflect the stream of water forward, down and to the sides (but not up).
Standard Response vs Quick Response
As their name implies, the difference between the two is the time needed for a fire sprinkler to activate. The main difference is the size of the bulb, which is 3mm for quick-response heads and 5mm for standard response.
Quick response sprinkler heads are intended for rapid fire response and are best for building with large number of people - schools, healthcare facilities, office buildings, etc.
Standard response heads are designed for low-hazard, low-occupancy buildings - such as warehouses & storage facilities, workshops, garages, etc.
K Factor
A nozzle discharge coefficient derived from formula Q = K x P ^ 0.5, where Q is water flow in GPM and P is system pressure in psi. It is used to determine suitability of a specific sprinkler head for a given space. Lower K-factor means less flow (e.x. K=3.0). Higher K-factor means more flow (e.x. K=8.0). K=5.6 is a standard NFPA requirement which works for most projects. K-factors lower than 5.6 are usually very limited to specific applications. High K-factors may be necessary where there's inadequate water pressure, and instead of installing or replacing a pressure booster pump, heads with larger orifices/openings (and thus higher K-factor) can be used.
Activation temperature
The color of liquid inside the glass bulb of a sprinkler head indicates the activation temperature (a point where temperature reaches a certain threshold and glass is shattered from internal pressure build-up):
Ordinary (most common for residential and commercial use):
Orange - 135° F
Red - 155° F
Intermediate (select commercial/industrial applications):
Yellow - 174° F
Green - 200° F
High-temperature (specialty applications):
Blue - 286° F
Purple - 360° F
Black - 440° F
