Things you should Know about UL Listed Fire Damper

Fire dampers are essential equipment, and they have become an indispensable part of heating, ventilation and air conditioning system. These dampers are of high importance because they offer passive fire protection. These dampers prevent the spreading of flames inside the ductwork. The dampers have fire resistance floors and walls which prevent the fire flame from reaching inside the main system through ducts.

All fire dampers must be thoroughly checked before installation, and they should qualify to meet underwriter’s laboratory requirements. Only UL fire dampers are allowed to be placed inside an air conditioning system.

These ducts must be installed in every HVAC system, and they cannot be ignored, because systems like air conditioner are prone to catch fire during high temperature, and if an air conditioner gets exposed to fire, then it can lead to severe fire hazards.

These dampers are essential to keep us safe during an emergency; they are life savers, so fire dampers must never be ignored. They functioned when heat from the fire caused a rise in normal room temperature, rise in temperature leads to the closure if the lock that is attached with the damper.

The attached link when exposed to fire has the property of melting, and cause the door to get closed. The main function of these fusible links is to melt when there is an increase in temperature and prevent the spread of flame.

Depending upon their mode of operation, they are broadly classified into dynamic fire damper and static fire damper. Both the types employ a different method to prevent the flow of fire into the system. The Dynamic fire dampers are placed in vertical barriers, whereas the static fire dampers are placed in barriers where the fan of the system will shut down in a case of fire. These dampers play a crucial role in any HVAC system, so there are special guidelines and measures that must be taken.

UL listed fire dampers are tested at higher temperatures, different pressures, and velocities. This is done to ensure reliability and provide a safety factor. All the dampers, whether they are used at commercial sites or residential sites are supposed to undergo a safety check before their installation and surpass under UL listed fire dampers. In case, they do not meet the required standards, and they should not be installed in the system.

Dirt Streaking: Sources, Causes, Effects And Solution

All kinds of supply vents, including the supply ceiling diffusers of your HVAC unit, can suffer from dirt accumulations. Many HVAC maintainers and professionals have to face the problem of dirt affecting both inner and outside areas of a ducting system. Apart from diffusers, the registers and grilles are also affected by the dirt and debris issue.

The sources of dirt streaking
Dirt streaking can be caused by the turbulent air that comes out of the air supply vent. The air leaving the supply vent comes out with great velocity, as it gets squeezed through vent’s louvers. The dirt particles, that the air contains, also become entrained and are deposited on the surfaces through which the supply air blows.

Sources of dirt particles
This dirt that comes out of the supply ceiling diffusers comes from mainly 2 sources.  It can come from the room or zone itself. The room air contaminants include candles, carpeting, people and pets, among others. The second source of the dirt particles is the unsealed openings. The sub floor or the drywall can have these boot penetrations that can form the unsealed openings. Particles get pulled towards space and get absorbed into the airstream.

Apart from these dirt causative factors, other conditions can also amplify dirt streaking. High amounts of room moisture can cause stickiness in the dirt particles, and they can get settled and get accumulated easily. Even when there is no moisture, then also the dirt particles get attracted towards the surfaces of the buildings. There is also the Coanda effect.

Solving dirt streaking
If the ducts, coils and the HVAC equipment are clean, then air streaking gets reduced quite substantially. There is no duct leakage and issues related to filter bypass. Now dirt streaking can be only caused by the sunsealed boot penetrations or by the particles that are present in the room itself.

If the sources of dirt are external, then vent penetration will have the “anti-smudge” rings. If the sources of dirt are internal, then the boot penetration should be sealed so that there are no gaps.  The UI classified fire dampers are a used so that the dirt build-up caused fire can be effectively controlled. Dirt, filth and debris can have great negative effects and are even causes of the fire. Hence, issues relating to the area should be solved immediately.