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What do you know about the Smoke Vents on the roofs of large retail stores?
So maybe you might have a new Costco or Home Depot going up in your area or maybe your a mutual aid department that does not have these types of stores in your first-in. But you do have the potential for responding mutual aid to cover a station... That's when the alarm comes in for a fire at the Home Depot and you have to have an understanding of how to ALL the built in fire protection features, including Smoke Vents.
SMOKE VENTS
Large retail store roof top showing both HVAC Units as well as several Plastic Domed Smoke Vents.
PLASTIC DOMED SMOKE VENTS
Domed smoke vents are commonly found in large warehouses, retail stores and production facilities as they satisfy concerns for both fire safety and energy efficiency in one unit.
All smoke vent doors open automatically when heat activates the UL listed fusible link, thus releasing smoke through the roof and making fire-fighting more effective.
Automatic venting of smoke and noxious gases is essential in effective fire safety concerns.
This aids firefighters in locating and more efficiently fighting the fire.
The release of smoke also aids in the safe evacuation of building occupants by improving visibility.
At the same time, domed smoke vents permits daylight to enter the building through the roof, thereby reducing if not eliminating the need for electric lighting during daylight hours.
Smoke vents in the closed position.
To open the Heat Smoke Vents, firefighters must pull a release cable.
A warning tag is attached to the Release Cable Pull Handle stating:
"WARNING! DO NOT PULL THIS RELEASE CABLE if you are not an authorized fire department employee. This equipment is an emergency fire safety device and should not be operated for any other purpose."
The lids will remain in the full open position until manually closed and hydraulic shock absorbers assure smooth operation, preventing damage to the unit. A manual cover release permits inside operation (outside operation optional) without disturbing the fusible link assembly and the latch automatically resets as the covers are closed manually. Once the cable has been pulled, both doors will remain opened until reset.
Caution labels warn firefighters that the smoke vent opens automatically once temperatures melt the fusible link.
The fusible link is located in line with the cable release system.
Tension is maintained on the fusible link with the use of a heavy duty spring.
View of the Smoke Heat Vent from the ground level.
To close the smoke heat vent, two people are needed to unlock the safety and compress the spring loaded vent doors.
The Spring Loaded Locking-Channel On Shock Absorber must be disengaged before closing the doors.
Both ends of the door have a locking mechanism that must be engaged using considerable force to put a load on the system.
Acceptance: Any required smoke control design that requires operation of mechanical equipment shall be functionally tested until proper operation of all required mechanical equipment and controls is demonstrated.
Examples of Other Equipment...
• fire protective signaling systems
• energy and building management systems
• HVAC equipment: dedicated and non dedicated to smoke control
• electrical equipment
• temperature control
• power sources and stand by power
• automatic suppression systems
• automatic door operations
• stair pressurization
• emergency elevator operations
Having an understanding of this type of mechanical ventilation will help you better prepare for incidents should you have one of these box type stores in your first in.
TCSS,
CBz
"Train as if your life depends on it... because it does!"
.
SMOKE VENTS
Large retail store roof top showing both HVAC Units as well as several Plastic Domed Smoke Vents.
PLASTIC DOMED SMOKE VENTS
Domed smoke vents are commonly found in large warehouses, retail stores and production facilities as they satisfy concerns for both fire safety and energy efficiency in one unit.
All smoke vent doors open automatically when heat activates the UL listed fusible link, thus releasing smoke through the roof and making fire-fighting more effective.
Automatic venting of smoke and noxious gases is essential in effective fire safety concerns.
This aids firefighters in locating and more efficiently fighting the fire.
The release of smoke also aids in the safe evacuation of building occupants by improving visibility.
At the same time, domed smoke vents permits daylight to enter the building through the roof, thereby reducing if not eliminating the need for electric lighting during daylight hours.
Smoke vents in the closed position.
To open the Heat Smoke Vents, firefighters must pull a release cable.
A warning tag is attached to the Release Cable Pull Handle stating:
"WARNING! DO NOT PULL THIS RELEASE CABLE if you are not an authorized fire department employee. This equipment is an emergency fire safety device and should not be operated for any other purpose."
The lids will remain in the full open position until manually closed and hydraulic shock absorbers assure smooth operation, preventing damage to the unit. A manual cover release permits inside operation (outside operation optional) without disturbing the fusible link assembly and the latch automatically resets as the covers are closed manually. Once the cable has been pulled, both doors will remain opened until reset.
Caution labels warn firefighters that the smoke vent opens automatically once temperatures melt the fusible link.
The fusible link is located in line with the cable release system.
Tension is maintained on the fusible link with the use of a heavy duty spring.
View of the Smoke Heat Vent from the ground level.
To close the smoke heat vent, two people are needed to unlock the safety and compress the spring loaded vent doors.
The Spring Loaded Locking-Channel On Shock Absorber must be disengaged before closing the doors.
Both ends of the door have a locking mechanism that must be engaged using considerable force to put a load on the system.
Acceptance: Any required smoke control design that requires operation of mechanical equipment shall be functionally tested until proper operation of all required mechanical equipment and controls is demonstrated.
Examples of Other Equipment...
• fire protective signaling systems
• energy and building management systems
• HVAC equipment: dedicated and non dedicated to smoke control
• electrical equipment
• temperature control
• power sources and stand by power
• automatic suppression systems
• automatic door operations
• stair pressurization
• emergency elevator operations
Having an understanding of this type of mechanical ventilation will help you better prepare for incidents should you have one of these box type stores in your first in.
TCSS,
CBz
"Train as if your life depends on it... because it does!"
.
Replies to This Discussion
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Permalink Reply by Doug on
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Excellent post, Capt. I would just like to add, to everyone that deals with these types of commercial buildings, to be very careful. Make sure you sound the roof as you move. Smoke vents, HVAC, electrical and environmental controls add a lot of weight to these roofs, which 99% of the time are supported only by lightweight steel trusses.
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Permalink Reply by Chief Dino on
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We have two big box stores in mutual aid area and had no idea how these worked. Thanks CBz! Do you know at what temperature the fusible link separates?
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It all depends on what metal alloys are used for the fuse link. Most are rated as low as 165ºF, some as high or above 360ºF
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Permalink Reply by Wade Seely on
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Captain,
Thanks for the great post, things like this should definetly be in pre plans, and passed on to the entire department.
TCSS
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Permalink Reply by Mike Schlags (Captain Busy) Retd on
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Excellent point about sounding the roof. There was recent post that did an exceptional job covering this.
Here's the discussion Posted by FETC on January 13, 2010
The Importance Of Sounding The Floor - Basic Skill Set Will Save Yo...
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thanks Doug for handling this, appreciate the assistance! CBz
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Permalink Reply by Fireyladd - Retired Chief Sharp on
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Good stuff Bro. Beats what color is your helmet an do you have blue lights all to heck. Good point Doug, common to have spungy roofs associated with this type of assemblies. Feels like walking on a trampoline on a good day. Keep em coming Bro.
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Permalink Reply by FETC on
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Good post CB, I did one on these some time ago. I want to point out that there is no need to sound the roof on a big box store if the store has these smoke vents. Why, the ventilation operation should be taken care of by the fire prevention officer and code enforcement. The big box stores I have in our district have more vents than ten truck companies could put into operation. Not to mention all of the heavy HVAC units, all adding up to alot of reasons for these to fall down. The smoke vents are fusible linked like Doug said, at fairly low temps.
Remember it is a big box THROW AWAY STORE, therefore in any type of decent fire, risk verse gain, and another thought that not many people think about is when we have a fire in these structures the fire department has very little control over the ventilation tactics, most of the auto smoke vents will pop, and you will have multiple holes as compared to having a truck company control the tactic.
TCSS
FETC
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Thanks, Doug.
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