Before we begin, a brief history
In 1874, pioneer and private business owner Henry S. Parmelee installed the first fire sprinkler system. Initially his aim was to protect his piano company in New Haven, Connecticut, from factory fires. Parmelee understood that the first line of detection and defense against an impending fire would be from above the factory floor. Leveraging existing patents and historical precedence, Henry designed and installed the first automatic fire sprinkler system. As a result, he effectively prevented cataclysmic damage to his hand-built wooden pianos and protected the lives of his employees and customers.
Well over a century from the first practical application of the sprinkler head, Parmelee's legacy lives. But the challenge of a fire in a hotel high rise or a commercial office building differs greatly from that of a warehouse containing large quantities of plastics. Therefore, different types of sprinklers have been designed to meet the needs of varied occupancy and hazard.
The six characteristics that define a sprinkler's ability to control or extinguish a fire and hence define its listing are:
- Thermal sensitivity
- Temperature rating
- Orifice size
- Installation orientation
- Water distribution characteristics
- Special service conditions
We’ll go into more detail on these characteristics in a future post.
This leaves us with two main sprinkler head response types that need to be understood when installing fire suppression systems from above which we are very proud to offer at Quick Response Fire Supply, LLC.
Standard Response versus Quick Response
Standard Response Sprinkler Heads (SR): The most widely used type of sprinkler head. Their effectiveness is based largely on their ability to pre-wet nearby materials that the fire has not yet reached and cool adjacent areas. Fire control with the standard response sprinkler occurs as the original fuel burns out. The fire spread is gradually slowed because the fire can’t ignite surrounding areas that have been pre-wet by the sprinklers. Because the fire is confined to one area, only sprinklers above the fire operate.
Quick Response Sprinkler Heads (QR): These are primarily used for light hazard applications and have a higher discharge pattern than the standard response heads. They've been developed for discharging water higher on the walls in order to keep the ceiling at a lower temperature. This helps prevent flash-over in a fire and increases the chance of human survivability which is why they are now the industry standard for installation in health care facilities, assisted living facilities, and residential occupancies.
The most common difference between a quick response sprinkler head (QR) and a standard response sprinkler head is known as thermal sensitivity. Quick response sprinkler heads activate slightly faster in a fire than a standard response head. As a result, extinguishing and suppressing the spread of fire in a more expedient fashion. Learn about a fire sprinkler's thermal sensitivity here.
Physically, the only difference between a standard response fire sprinkler and a quick response fire sprinkler is the size of the bulb. Standard response sprinklers have a 5 mm glass bulb while quick response fire sprinklers have a 3 mm glass bulb. Can you spot the difference?
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Cost Efficiency versus Product Practicality
Ceiling height is a key factor and you should always take into consideration the temperature of the environment during all the seasonal months of the year. The size of the spray area should be a primary concern when you installing a specific type of sprinkler head. Depending on what type of building you are outfitting, sometimes substituting several standard response sprinkler heads for a fewer amount of quick response sprinkler heads may be more of a cost effective approach depending on how large or small of an area you are working in.