Fire Dampers Questions

How should fire dampers be installed?

It is important to remember that even though the fire damper you purchase is CE marked, in order to perform a compliant installation it must be installed as advised by the manufacturer in their published installation documents. Any deviation from a manufacturer’s published installation method could render the installation non-compliant, and therefore technically illegal. It is also important to remember that different manufacturers’ installation methods may vary. Fire damper inspection and testing Inspection and periodic testing of fire dampers is an important task all building owners must undertake. Insurance companies are waking up to the importance of fire dampers, and in the event of a fire may refuse to pay out any claims if proof of regular inspection and testing cannot be provided. BS 9999 states that fire dampers should be inspected and tested at least once per year.EN 15650 goes further, stating that intervals should not exceed 6 months.Instructions for how to inspect and maintain fire dampers are advised by manufacturers in their published documentation. Get in touch with any questions If you have any questions about the installation of fire dampers, please do not hesitate to contact HVC today.

Fire Dampers Questions

What is a fire damper?

According to EN 15650:2010, the European standard which governs fire dampers, a fire damper is ‘a device to be used in conjunction with partitions to maintain fire compartments in heating, ventilating and air conditioning installations.’ Simply, they are devices that act to maintain the integrity of a fire compartment, during a fire, at locations where air ductwork penetrates through the partitions defining that compartment. How does a fire damper work? Fire dampers almost universally consist of: A frame One or more moveable blades An actuation device, e.g. springs or specialised actuators A thermal release mechanism During normal operation the thermal release mechanism holds the actuation device (and therefore the blades) in an open position, thus allowing airflow through the duct to which the damper is fitted. Upon experiencing a trigger condition, e.g. the temperature inside the duct exceeding the thermal release mechanism’s rated temperature or loss of power to the actuator, the thermal release mechanism releases, permitting the actuation device to quickly move the blades to a closed position. At this stage, the duct is shut down, and the integrity of the fire compartment maintained. What Standards are Relevant to Fire Dampers? On the 1st of July 2013 in the UK, it became mandatory under the Construction Products Regulation that all fire dampers were to be CE marked to indicate compliance with the requirements set out in EN 15650:2010, which contains the basic performance requirements for fire dampers. This document also makes reference to EN 1366-2 which defines the furnace testing associated with these products, and EN 13501-3, which provides details on their fire resistance classification.These three documents together define almost everything relating to what a fire damper is, how it is tested and how to classify its performance in order to permit both meaningful comparisons between different models, and verification that any chosen model is suitable for the installation in which it is to be used. Also of particular relevance are: EN 15882-2 – Commonly referred to as EXAP, this standard defines how to treat any variations pertaining to the construction of a fire damper or its installation, in relation to how it was originally tested. EN 1751 - Defines how to test the aerodynamic properties of fire dampers, specifically blade leakage, case leakage and resistance to airflow. ISO 21925-1 (Annex C) – Describes the testing required for thermal release mechanisms. EN 60068-2-52 – Environmental testing (salt spray). Get in touch for more information If you have any questions about fire dampers, please do not hesitate to contact HVC Supplies today.

Diffuser Questions

What size hole do I need to cut for my grille, diffuser or louvre?

The same as the nominal. Unless stated otherwise and in the vast majority of cases, the size you give us will be taken to be the nominal, i.e. the size of the aperture into which you will be fitting the grille, diffuser or louvre. From this size HVC shall deduct a tolerance, permitting the neck of the unit to fit into the hole comfortably. This tolerance is normally between 9 – 15mm, however, does vary by product type, therefore please download the specific product PDF for further details. There are notable exceptions to the above: Series CD ceiling diffusers are normally specified by their neck size, not their nominal. However, you should still cut any holes into which CDs are to be fitted to the nominal. This also applies to Series SFCD and LFCD circular diffusers. The nominal size of dampers will normally refer to the ductwork size they are to suit, not to any aperture size. Got more questions about grilles, diffusers or louvre? get in touch If you have any more questions about grilles, diffusers or louvres, please do not hesitate to contact HVC Supplies today. Our dedicated customer service team will be more than happy to answer any queries.

Weather Louvre Testing

What is BS EN 13030:2001?

EN 13030 is a harmonised European standard which specifies a method for measuring the performance of louvres subject to simulated rain and wind pressures, both with and without air flow through the louvre under test. It provides a common basis on which to compare the performance of weather louvres of different designs, through the use of two defined performance criteria.  Manufacturers wishing to test louvres against this standard typically supply a 1m x 1m sample for evaluation to a suitable test house, for example BSRIA, based in Bracknell, Berkshire.  What performance criteria are louvres evaluated against? EN 13030 states sample louvres should be evaluated for performance in terms of: Resistance to ingress of simulated rain How effective is a louvre at removing simulated rain (75 l/h) from an airstream when subjected to a constant wind speed (generally 13 m/s) and various air flow rates (0 m/s to 3.5 m/s in 0.5 m/s increments). Class A – Excellent (99% effective and above) Class B – Good (between 95% and 98.9% effective) Class C – Fair (between 80% and 94.9% effective) Class D – Poor (less than 80% effective) Coefficient of entry/discharge How much resistance does a louvre present to airflow?  Class 1 – Excellent (Ce/Cd of between 0.4 and 1.0) Class 2 – Good (Ce/Cd of between 0.3 and 0.399) Class 3 – Fair (Ce/Cd of between 0.2 and 0.299) Class 4 – Poor (Ce of 0.199 and below) What does it mean to have a louvre tested against EN 13030? The testing of a louvre against EN 13030 is not in itself a guarantee of performance, rather the louvre is graded against the two above performance criteria. It is therefore important to understand the performance requirements of any application to ensure appropriate louvre selection.   Contact HVC today for more information At HVC Supplies, we offer one of the widest ranges of louvre systems available from any UK manufacturer, with our range being constantly expanded to suit new industry requirements and customer demands. Online you will find a full range of louvre systems, from basic single bank weather louvres to Class A-rated high-performance louvres and sand trap louvres. With a dedicated design team working on both new developments and bespoke projects, why not try HVC for your next project? For further information about our product range, or to find out more about our certifications, please get in touch with us today. Our team of experts will be happy to answer any questions that you may have. 

Louvre Questions

What is the Difference Between Dampers and Louvres?

Dampers and Louvres are both very important parts of the wider HVAC system. Whilst the two can look similar to the untrained eye, they do separate (but equally important) jobs. What is a Damper? A Damper is a valve that stops or regulates the flow of air inside a duct . There are a number of different types of Damper, each for specific uses. Fire Dampers, as we've discussed in our knowedge hub article about fire dampers, impede the spread of fire and smoke in the event of a fire. Volume Control Dampers help to manage the flow of air in a building as part of the HVAC system.  Non return Dampers are opened by airflow, and closed by gravity, and are seen in both commercial and residential properties, these Dampers are used to permit air to flow in one direction, but not the other, therefore minimising heat loss from within a building when a system is inactive. Non-Return Dampers if set up correctly have no need for a motor, or manual input. True Volume Control Dampers are used for balancing or throttling throughflows, and can be either motorised or manual. Examples of True Volume Control Dampers can be found here S900B, S800B - an offshoot of this type of Damper is a Shut Off Damper that offers a tighter seal in a closed position, these can also be made to be manual or motorised. Examples of Shut Off Dampers can be found on our site, S900C and S800C. Unlike Fire Dampers, which are almost always made of steel in UK Volume Control Dampers, Non Return Dampers and Shut Off Dampers can be found in a much wider range of materials, such as aluminum and uPVC. Motorised Dampers are most often electrical, but can also be pneumatic. Electrical motors are available with a range of features to tailor the specific use of a Damper. Modulation as an example can allow control of positions between open and closed going beyond a simple shut off or isolation and enables precise control of the flow rate. Motorised Dampers can also be automated to be controlled by thermostats as part of a larger HVAC system. Spring Return Dampers can be used to ensure the blades return to a fail position in an instance of loss of power, or hydraulic pressure. For more detailed information on specific types of Dampers, please look to our Knowledge Hub for articles on further applications and subtypes. What are Louvres? Louvres, on the other hand, are positioned on the exterior of the building to allow fresh air through and protect the HVAC system against water, dirt and debris ingress, such as rain and leaves. Traditionally, they sit on exhausts or air intakes and have fixed blades which do not close. This means that, if air shut off is required, a secondary damper is required. For example, HVC’s NCA S800C – Heavy duty shut-off.  Differences Between Dampers and Louvres Louvres are designed to prevent water, dirt and debris ingress; dampers are designed to manage airflow and impede the spread of fire and smoke (in the case of a Fire Damper). Whether controlled by gravity or motor, the blades on a damper can open or close depending on the requirements. The blades on a louvre are stationary. Contact HVC Today For more information about our external weather louvres, dampers, or any of the products in our range, get in touch with HVC today. Our dedicated and experienced team will be happy to answer any questions you may have.

Louvre Questions

What is a Sand Trap Louvre?

Sand Trap Louvres, as their name suggests, are a type of louvre designed to impede dust, sand and other aggregates from entering a HVAC system. In this article, we’ll be going over the specifics of where the Sand Trap Louvre should be installed, why they’re necessary, and how they work. Where Are Sand Trap Louvres Installed? Normally, they are installed in a similar way to other types of louvres; just like other types of louvre, their specific placement will depend on the design of your HVAC system. However, the key difference between normal louvres and Sand Trap Louvres is that Sand Trap Louvres, in addition to the mitigation of rain ingress of normal louvres, also remove larger airborne particulates from the air. This makes them appropriate for areas where there is large amounts of airborne sand or dust which could be into ventilation systems. This makes them suitable for desert areas of the world such as the Arabian gulf, but is equally valid near quarries or beaches closer to home. Why Are Sand Trap Louvres Necessary? In these areas, the specification of sand trap louvres should be considered over standard louvres. They will function as a pre-filter, preventing larger airborne particles from being drawn into the system. This will not only reduce the possibility of damage to dampers, fans etc., but also extend the life of filters, maintaining system efficiency for longer and reducing costs associated with cleaning and replacement. How Do Sand Trap Louvres Work Sand Trap Louvres work via a simple system of interlocking louvre blades. These catch up to 92.5% of dust and sand. This material falls onto a sloped cill, where it is then expelled from the louvre by gravity. Our Series STL sand trap louvre has been independently tested by BSRIA against EN 13181:2001, the test results are detailed in our product brochure and the full report can be sent on request. Depending on your needs, this type of Louvre can be further modified with a rear-mounted volume control damper installed, in order to control the amount of air that passes through the louvre. As well as this, there are a range of powder coating options available. Get in Touch With HVC Today For over fifty years, HVC have been providing our customers with high-quality HVAC components, including fire dampers, volume control dampers, and louvre doors of various sizes. Our products have all been designed with customer safety in mindm.  For information on our range of Sand Trap Louvres, or any of our other products, get in touch with HVC today. Our experienced and dedicated team will be happy to answer any questions you may have.

Fire Dampers Questions

How are fire dampers tested?

Everyone knows fire dampers have to be fire tested in order to become CE marked, but what exactly does this testing involve?  Legislation Fire dampers are subjected to fire testing as prescribed by EN 1366-2, this full scale furnace test is arguably more severe than any fire likely to be seen in the real world, however it is this severity which ensures any damper which satisfies it can be relied upon to perform in a real fire scenario.   Performance Test Testing against EN 1366-2 demands that a sample damper is tested in the substrate it is to be certified for, this could be a concrete floor slab, flexible (plasterboard) wall, or a proprietary system such as a fire curtain or shaft wall. Test houses such as BRE, Applus or Gryfitlab will build a sample construction of at-least 3m x 3m within a large steel frame. Once the damper is installed as per the damper manufacturer’s instructions within the substrate, the entire assembly is craned into position on a gas fired furnace, capable of reaching temperatures approaching 1200°C. A plenum box is then connected to the unexposed side of the damper, serving as the connection point between the damper itself and ducting.  Once the pre-test formalities are complete, such as 50 successful open and close cycles and signing off of the installation by the manufacturer’s witnessing representative, the equipment is readied for testing. High temperature fans are set to draw a constant 0.15 m/s through the damper, sensors are verified to be working and then the furnace is lit. Fire dampers always start a test in the fully open position, and have a maximum of 2 minutes to close after the test commences. Given the nature of fire testing, visual verification of closure is not reliable, therefore closure is verified by monitoring of the under-pressure within the connection plenum, which needs to increase by at-least 50 Pa over a 5 second time period. Assuming the damper closes within the allowed time, fans will be set to maintain an underpressure of 300 Pa within the plenum, and leakage readings through the damper will start being taken, although they only have consequence once 5 minutes have passed to allow stabilisation. All being well, the test will then proceed for the time period requested by the manufacturer. In order to apply extended field of application (EXAP) rules, manufacturers will normally request the test duration is 10% more than the duration by which dampers are marketed, i.e. at HVC we will normally test a 2 hour rated damper for 132 minutes.  Monitoring Performance Criteria  Throughout the test duration, there are two main performance criteria which are monitored; leakage and installation stability. Leakage through the damper should not exceed 360 m3/hr/m2 for ‘E’ rated dampers, or 200 m3/hr/m2 for ‘ES’ or ‘EIS’ rated dampers, and if EXAP rules are to be applied the damper must not get within 10% of these volumes. Installation stability looks not only for whether the installation remains intact, but also whether anything on the unexposed side (i.e. not within the furnace) ignites for more than x seconds, should any of these rules be broken, the test will be considered a failure.  If all goes well and the test is successful, then the result can be factored into classification and EXAP documents, ultimately feeding into the certificate of constancy of performance from which manufacturers can draw up their declaration of performance, allowing them to market their damper.

Diffuser Questions

What Are Ceiling Diffusers?

The term ‘ceiling diffuser’ normally refers to louvre faced ceiling diffusers – the louvre ventilation terminals seen in the ceilings of commercial spaces all over the world. Louvre faced ceiling diffusers have been popular for decades. Their architectural appearance belies a high performance diffuser with a multitude of configurations and options, including multiple blow directions, rear mounted volume control dampers and removable cores. These options assist both initial installation and ongoing maintenance. Intended for supply applications, these diffusers can also be used in a return (extract) function when a consistent appearance throughout an installation is required.   Installing Ceiling DIffusers Louvre faced ceiling diffusers can be installed in various methods: Laying into drop in ceiling tile systems (normally 600mm x 600mm or 500mm x 500mm). Pre-punched fixing holes for screw fixing into plasterboard ceilings.  Burgess tile system installation through use of dedicated Burgess compatible frame.  Integration into other proprietary ceiling tile systems, e.g. Armstrong.  Installed properly, a ceiling diffuser will provide more than adequate infusion of fresh air into a given space, providing adequate ventilation and temperature control.  Ceiling Diffusers From HVC  HVC has been manufacturing high quality diffusers since the 1970’s. Today, we are one of the UK’s largest suppliers of this consistently in demand product. We hold thousands of standard size ceiling diffusers in stock, including those with and without opposed blade dampers for localized volume control, in our West Midlands warehouse. Thanks to our supply chain and quick service, we are able to supply even the largest orders on a next day basis. As well as a range of diffusers, we also offer linear slot diffusers, as well as a full range of fire dampers and louvre accessories.   In addition to the supply of standard sizes, we retain the ability to manufacture bespoke units in non-standard sizes, with our renowned industry beating lead times.  For further information on our range of ceiling diffusers, or any of our products, please contact HVC today.

Diffuser Questions

What Are Swirl Diffusers?

Arguably the most effective type of ceiling mounted diffuser available, swirl diffusers are renowned for their high performance and their true 360 degree throw.  An alternative to louvre-faced ceiling diffusers, swirl diffusers are generally available in either fixed or adjustable variants. Fixed swirls, as their name suggests, have a circular pattern of fixed blades designed to throw air radially across the underside of a ceiling. Using the Coanda effect, this newly supplied air will spread widely until slowing and falling into the occupied space, thus a wide area can be ventilated from a single point.  Adjustable swirl diffusers differ in that directly behind the fascia plate are individually adjustable blades. These can be set to throw air in any direction. As such, they can throw air radially like a fixed swirl, but they can also throw it in a single direction across the ceiling or even straight down. This makes adjustable swirls well suited to installations where ventilation patterns may need to be changed, without the need to physically move diffusers.  Swirl Diffusers From HVC  Both fixed and adjustable swirl diffusers are also available in circular or square formats. Circular swirls tend to be mounted directly to the ends of ductwork in large open plan spaces like airport terminals, square swirls in contrast generally suit lay in ceiling tile systems commonly fitted into commercial spaces, such as offices.  HVC holds one of the largest stocks in the UK of square swirl diffusers, in both fixed and adjustable variants, giving us the ability to supply even the largest orders on a next day basis from our centrally located warehousing facilities in the West Midlands. As well as swirl diffusers, we also carry a full range of HVAC products, such as linear slot diffusers and fire dampers. Furthermore, we can also supply a range of ancillary products, like specially adapted plenum boxes, to suit swirl diffusers and single blade dampers for local volume control.  For further information on our range of ceiling diffusers please contact HVC today.

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