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Residential Pendant Fire Sprinkler Heads – How do they Work?


Two types of pendant fire sprinkler heads are currently available and work in different ways:

  • concealed residential pendant fire sprinkler heads
  • traditional pendant design fire sprinkler heads

Concealed fire sprinkler heads are more commonly installed in, and appropriate to, residential settings nowadays.

Comparing Pendant Sprinkler Heads

These two types of fire sprinkler head differ in a number of ways:

  • how the residential pendant firesprinkler heads work
  • how the residential pendant firesprinkler heads are designed
  • how the residential pendant firesprinkler heads are placed and their visibility

How Do Pendant Fire Sprinkler Heads Work?

Concealed Residential Fire Sprinkler Heads

concealed sprinkler heads.

Concealed residential pendant firesprinkler head

Concealed residential fire sprinkler heads are classified as ‘fast response’ heads, facilitated by the sprinkler system activating at an early point in the development of a fire.  In contrast to the pendant design, they are a two-stage device.

In the event of a fire reaching its operating point, the flat cover ceiling plate will fall from the device, allowing the deflector plate of the sprinkler head to drop below the ceiling level. As the temperature at ceiling level increases to 74 degrees Celsius, a bi-metal strip activates and releases the seal, enabling the full flow of water to be directed towards the fire.

Each fire sprinkler head is activated independently, maximizing pressure, flow and delivery of water to the fire and avoiding water damage to areas that are not alight.

Traditional Pendant Fire Sprinkler Heads

pendant sprinkler head

Exposed residential firesprinkler head

Unlike concealed residential fire sprinkler heads, the traditional pendant design heads are a single-stage device, not concealed and project below the level of the ceiling, allowing water to travel horizontally if the head is activated.

Individual sprinkler heads only operate when heated to their pre-set activation temperature by the hot gases from a fire.  Fire sprinkler heads outside the immediate area of the fire do not open, so water isn’t sprayed onto areas that are not alight, thus reducing the amount of water used and water-related damage, whilst maximising available water pressure.

In pendant design fire sprinkler heads such as that shown in Figure 2, the activation process and make-up of the sprinkler head is fundamentally different to that described for residential concealed fire sprinkler heads.  Every sprinkler head in the system is kept closed by a glass, heat-sensitive, liquid-filled bulb, which serves as a plug, holding back water from the supply pipes. When the temperature around the sprinkler head reaches its pre-set activation level, the bulb breaks as the liquid inside heats up and expands.  The bulb can no longer function as a ‘plug’, thus allowing water to enter the sprinkler head and douse the fire.

Design of Pendant Sprinkler Heads:

Concealed Residential Fire Sprinkler Heads

Unlike pendant fire sprinkler heads, concealed residential fire sprinkler heads are designed to be aesthetically pleasing, not just effective.  The sprinkler head, which is about the size of a down-light, resides in the ceiling void, concealed from view by a flat cover plate which sits flush to the ceiling.   These cover plates are usually white.

Traditional Pendant Fire Sprinkler Heads

Pendant fire sprinkler heads are a traditional design, often used in commercial premises.  Whilst effective, these sprinkler heads sit below the level of the ceiling and contribute little to the aesthetic value of their surroundings.

Placement and Visibility:

Concealed Residential Fire Sprinkler Heads

Concealed residential fire sprinkler heads reside out of sight, and unlike pendant fire sprinkler heads, cannot be seen when not in use.

Traditional Pendant Fire Sprinkler Heads

Projecting below the level of the ceiling, traditional pendant fire sprinkler heads are not concealed and project below the level of the ceiling, remaining in full view at all times.

Summary of Differences:

Concealed Residential Fire Sprinkler Heads Traditional Pendant Fire Sprinkler Heads
Location Ceiling void Project from ceiling
Not visible when inactive Yes No
Blend with surroundings Yes No
Fast Response Activation Yes Yes
Limit water damage Yes Yes
Two stage activation Yes No
Helpful to architects & designers Yes No
Obvious to occupants No Yes
Ease of service Yes Yes

Choosing  A Residential Pendant Fire Sprinkler Head

Rarely valued for their aesthetic value, traditional pendant fire sprinkler systems have now been generally replaced by concealed residential fire sprinklers, which not only blend with but enhance the space they’re designed and installed to protect.

Why Should I Choose Concealed Sprinkler Heads?

Concealed sprinkler heads are becoming a more and more popular choice for our customers. With a concealed sprinkler head, the system will barely be noticeable, but it will be just as effective as a traditional pendant system. Being able to mask the system means the features of your building are spoilt. Some of the reasons we think you should choose concealed sprinkler heads are:

  • Blends in with surroundings
  • Design is discreet and suits any style of property
  • Fast response time
  • Suitable for all types of buildings
  • Limited water damage

For more information on the concealed sprinkler head systems we offer please don’t hesitate to get in touch. Alternatively browse our website to find out more information about the products and services we offer.

Contact RAD Fire Sprinklers For Concealed Sprinkler Systems

If you’re interested in having a concealed sprinkler system installed, then don’t hesitate to contact RAD Fire Sprinklers. We have a team of designers and engineers, who’ll work with you to ensure your concealed system work both for the style of the property and for its desired requirements. With all work carried out by professional engineers, we guarantee a high standard of finish. With a range of concealed fire sprinkler systems to choose from, we have something for all types of properties. When it comes to concealed systems be sure to get in touch with RAD Fire Sprinklers.

Frequently Asked Questions About Residential Sprinkler Heads
Will people be able to see the sprinkler system?

No. Concealed sprinkler systems are designed to blend seamless into the roof or ceiling space. We believe in working closely with our customers to ensure they choose the best type of system for both their property and requirements.

Aren’t sprinklers ugly?

Not any more. In more recent years, fire suppression systems have become much more stylish and they are designed to blend in and not stand out.

Will you design the concealed sprinkler system for me?

Yes! When you choose RAD Fire Sprinklers for our concealed fire suppression systems, you’ll work closely with our engineers. We’ll created a concealed design that matches the style of your property.

Why should I choose a concealed over a traditional system?

Concealed systems offer all of the same great protections that a traditional system offers and more. With a concealed fire sprinkler system you can keep your property and the people in it safe without compromising on the aesthetic of the property.

How much does it cost to have concealed sprinklers installed?

The cost of a concealed sprinkler system depends on a number of factors such as the size of the system and how much structural work is required to install it. We offer high quality systems at affordable prices. Get in touch with RAD Fire Sprinklers today for a quote.


Find out how automatic sprinklers work here on our blog page.

Diligent & a very professional team. A joy to deal with. Will certainly be calling on them to help with many more future schemes.
Jason Tema
22:17 08 Jul 19
Great team, fitting sprinklers, saving lives & property... What more could you wish for!!!
Colin P
17:53 01 Jul 17
Excellent company & great service... This company rocks! They sprinkle fires & save lives!!!
Music N Videoz
07:15 16 Dec 16
As somebody who feels that it should be a necessity for all properties to have fire sprinkler systems, I am a big fan of this company. I have used them numerous times to service my home system and they are very knowledgeable. I would highly recommend their service.
Kate Fraser
09:25 30 Mar 15
One look at Rad Fire Sprinkler's website will tell you that these guys know exactly what they are talking about when it comes to Fire Sprinklers and the legislation surrounding fire safety. A very trustworthy company.
Adam Hudson
16:45 15 Nov 13

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RAD Fire Sprinklers Ltd.
58A St John’s Road
Tunbridge Wells, TN4 9NY

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Tel: 01892 680 090

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