Fire Damper vs Fire Smoke Damper

Fire Damper vs Fire Smoke Damper

Do you know the difference between fire dampers and fire smoke dampers?

This is a questions that seems to come up a lot in the fire alarm install and design world.  The definition of a damper is "A person or thing that damps or depresses".  In other words it is a plate that is placed within the duct work of an HVAC system to regulate or in some cases stop air flow.

Now in the fire alarm industry we are more concerned with the terms "Fire Damper", "Smoke Damper" or "Combination Smoke Fire Damper".  Whats is the difference?  Well it is actually quite simple as we explain below.

·                  A "Fire Damper" as defined in the CMC (California Mechanical Code) 2010 Edition Section 206.0 - "An automatic-closing metal assembly of one or more louvers, blades, slats or vanes that close upon detection of heat so as to restrict the passage of flame and is listed to the applicable recognized standard."  The automatic means can be accomplished one of two ways: 1) by a fusible link that will melt upon heat thus releasing the louvers into the closed position.  2)  by motorized actuators that will close upon loss or gain of power.  These are typically controlled by and addressable relay module.

·                  A "Smoke Damper" as defined in the CMC (California Mechanical Code) 2010 Edition Section 206.0 - "A damper arranged to seal off airflow automatically through a part of an air duct system so as to restrict the passage of smoke and is listed to the applicable recognized standard."

·                  A "Combination Fire Smoke Damper" is exactly that, a combination of a "Fire Damper" and a "Smoke Damper".

When are they required and how do I know when to use what type?

Keep in mind that the fire alarm contractor will not be providing or installing these.  However, it is nice to know what to look for on a bid set of plans or during a job walk.  First up is the "Fire Damper".  A fire damper is installed in HVAC duct work at the intersection of a rated barrier such as walls or partitions.  The damper is in place to secure the integrity of the rated barrier in the event of heat or flames around 165 degrees F.  Like we stated above, the fusible link will melt thus releasing the louvers on the damper.  Once the louvers are closed or shut, the fire barrier is now secured from allowing flames to penetrate prior to the rating level of the barrier itself.

Smoke dampers are similar however, they close in the presence of smoke.  Now since the smoke damper cannot obviously sense smoke, we need to install a smoke detector. The smoke detector can either be a system smoke (tied to a building fire alarm system) or a stand alone smoke solely in place to activate the smoke damper.  Smoke Dampers are required to be installed on walls that separate smoke barriers.  

What's a smoke barrier you ask......  A smoke barrier is a continuous surface such as a wall, floor, or ceiling constructed to restrict the movement of smoke.  A smoke barrier can be either vertical or horizontal. 

Now a "combination smoke fire damper" is located in a situation where both fire rating and smoke barriers come into play.  A combination fire smoke damper also needs a smoke detector just like the smoke damper.  The smoke detector can either be a duct smoke detector (System Sensor D4120 or DNR) or a pendant mounted detector within the duct work itself.  Once the detector senses smoke particles it will either through programming or local relay base close the damper louvers.

Commissioning and maintenance of Fire Blankets

Commissioning and maintenance of Fire Blankets BS EN 1869 – Code of practice

1. Scope

This code of practice gives guidance on:

·       Regular inspection of a fire blanket

·       Regular maintenance of a fire blanket

·       Life of a fire blanket

·       Reasons to render a fire blanket unserviceable

2. Terms and Definitions

2.1. Container

The box, packet or cabinet (including closures) in which a fire blanket is normally housed.

2.2.

Fire Blanket

A fire blanket is a safety device designed to extinguish small incipient (starting) fires. It consists of a sheet of fire retardant material which is placed over a fire in order to smother it.

Small fire blankets, for use in kitchens and around the home, are usually made of either fibreglass or woven-nylon coated with silicone-based flame retardant and folded in to a quick-release container for ease of storage.

2.3.

Hand hold devices

Hand hold devices often made of woven material, securely attached to the blanket which can be seen and accessed from outside the container which allow the user to release the fire blanket from the container ready for deployment.

2.4.

Manufacturer’s instructions

Instructions written by the manufacturer to aid users deployment of the fire blanket.; including any instruction which aids the service provider to carry out maintenance of the blanket.

2.5.

Service provider

Person with the training and experience, with access to the relevant tools, equipment and information, manuals and knowledge of any special procedures recommended by the manufacturer of the fire blanket, to carry out the relevant maintenance procedures

2.6.

Responsible Person

Person or persons responsible for, or having effective control over, fire safety provisions adopted in or

appropriate to the premises or building or risk where an fire blanket is installed

NOTE For the purposes of this document, the term “responsible person” includes a nominated representative.

3. Process of Commissioning

The commissioning of a fire blanket should be carried out by a service provider as defined in 3.5. Upon removal from its packaging and transit protection, and immediately prior to placing in its designated place, the fire blanket should undergo this sequence of commissioning service actions:

4. Mounting

4.1.  Fire Blankets should be mounted so as to position the hand hold devices approximately 1.5 m from the floor.

4.2.  The positioning of kitchen furniture and/or equipment should not preclude access to the blanket.

5. Visual Inspection by the Responsible Person

5.1    The responsible person should carry out visual inspections of all fire blankets regularly. These visual inspections should be carried out at least monthly. When circumstances require, inspections should be carried out more frequently.

NOTE 1 Fire legislation in England & Wales, Scotland, Northern Ireland and its associated Guidance Notes suggest that good practice is to determine whether the fire blanket has been used and to check for damage on a weekly basis.

5.2    When carrying out these visual inspections, it should be ensured that:

5.3    each fire blanket is correctly located in the designated place;

5.4    each fire blanket is unobstructed and visible

5.5  the operating instructions of each fire blanket are clean and legible and face outwards;

5.6    each fire blanket container is not obviously damaged and that the hand hold devices are visible and undamaged

5.7    the tamper indicators of each fire blanket, where fitted, are not broken or missing.

5.8    The responsible person should record the results of these visual inspections and arrange for corrective action, where necessary, by a service provider. In the event of doubt the responsible person should arrange for a service provider to examine the fire blanket.

NOTE 2 Responsible persons have obligations under fire legislation in England & Wales, Scotland, Northern Ireland to use a service provider to maintain extinguishing equipment in an efficient state, in efficient working order and in good repair, where it is necessary to provide such equipment to safeguard employees in the event of fire.

6.    Basic service

6.1    The responsible person should ensure that basic service be carried out at 12 monthly intervals. The maintenance intervals given for basic service have for practical purposes a tolerance of ±1 month. Intervals should be taken from the date of installation or the last basic service. Intervals may be shortened, on the recommendation of the service provider where inspection reveals environmental and/or special hazards, or at the request of the responsible person.

6.2    The basic service of a fire blanket should be carried out by a service provider as defined in 2.4. The fire blanket should undergo this sequence of commissioning service actions: 

7. Labelling

7.1.  General

Any labelling that is applied to the fire blanket container should not obscure any marking required by BS EN 1869;

7.2    Maintenance label

7.2.1          The maintenance record should be indelibly marked on a durable label that is fixed firmly to the fire blanket container without obscuring any of the manufacturer’s markings and instructions. Where there is no more space on the maintenance label and a new label is fixed, the date of commissioning should be marked on the new label.

7.2.2          The following information should be given on the maintenance label:

7.2.3          type of action (commissioning or basic service)

7.2.4          name and postal address of the maintenance supplier;

7.2.5          a mark clearly identifying the service provider;

7.2.6          the date (year and month) of the action in a) above;

7.2.7          the date (year and month) of commissioning

This information should be readable without any special equipment.

Any additional information for the benefit of service providers may be shown in a more compact form, such as bar codes.

NOTE 3 The information on the maintenance label of each fire blanket may additionally be entered into a central record. In this way one aspect of the important information on fire prevention can be kept readily available.

8. Evaluation of fitness - Blankets which are to be condemned

Any fire blanket with a major defect or defects which make it unsafe for use should be immediately removed from its designated place, and marked “CONDEMNED” together with the reason for this assessment. The responsible person should be advised in the written report (see 9) that a permanent replacement is needed as soon as possible. Evaluation of whether the damage or wear to a fire blanket make it unsafe for use depends on the judgement of the service provider.

8.1.  Conditions indicating that a fire blanket is unsafe for use

Potentially the most serious hazard presented by a defective fire blanket is it’s inability to either (a) be deployed or (b) starve a fire of oxygen, allowing the fire to burn uncontrollably after deployment. These could be caused by any of the following conditions:

8.1.1          wear, contamination or damage to the fire blanket material.

8.1.2          wear or damage to the fire blanket hand hold devices;

8.1.3          serious damage to the container;

8.1.4          fire damage to the container or fire blanket;

8.1.5       age. Follow manufacturers instructions or if there are none then if more than 7 years from date of commissioning consider replacing the blanket.

8.2    Additional reasons for condemning a fire blanket include the following (unless rectified by the replacement of the appropriate components):

illegible marking or operating instructions;

instructions not in English;

9.    Provision of a written report

The service provider should advise the responsible person in a written report:

9.1    of any fire blankets that have been condemned or are missing;

9.2    of any permanent replacement fire blankets required to replace those reported in a);

9.3    of any additional fire blankets required to ensure that the level of cover at the premises is appropriate for the risks present;

9.4    that any replacement or additional fire blankets reported in b) or c) should be provided as soon as possible; and

9.5    of the responsible person’s obligation under fire legislation to provide an appropriate level of fire-fighting equipment at all times.

10. Maintenance documentation

A certificate of inspection should be issued in all cases.

      10.1   The certificate of inspection should include the following information:

10.2    the name, postal address and telephone number of the maintenance company;

10.3    the date of maintenance;

10.4    identification of the maintenance technician;

10.5   a list of all fire blankets included in the maintenance programme; including all nonconforming equipment, and recommendations for appropriate corrective action or reference to where this information can be found;

10.6    the signature of the responsible person, which should be obtained upon completion of the service visit and prior to the service technician leaving the premises, or a record of the reason why this is not possible (e.g. unmanned sites);

 11. Permanent replacement of a Fire Blanket.

It is the duty of the responsible person to arrange for permanent replacement fire blankets to be put into place as soon as possible after inspection has shown that some fire blankets should be replaced. The service provider is responsible for bringing this duty to the responsible person’s attention in the written report.