When its finally time to shut down the AC for the summer and fire up that furnace in preparation for the coming winter, take a moment to revisit our friends in the ductwork, the dampers. Most ductwork is either shown in single line or double line. In order to understand how to read HVAC drawings, you have to understand the road signs (HVAC Symbols). It can be helpful for new installations or to replace the old ones in your house or commercial buildings. Go back to the air-conditioning dampers and make the necessary adjustments whether you want the room to be cooler or warmer than open or close the damper, respectively. Dont be confused by the variations of the same symbol from drawing to drawing. Volume dampers are static dampers, meaning they do not have actuators and are meant to be adjusted one time when the system is balanced. It uses a rotary-to-linear mechanical actuator-assembly system for precise and dependable calibration. What is the difference between a control damper and a balancing damper? 17.2), it follows from Eq. Parallel blade dampers are con-structed so all the blades move in the same direction and in parallel. The following are used often throughout the mechanical drawings to indicate which type of air is in the ductwork, or which type of air distribution is being referenced. Effect of Inlet Louver on an Opposed Blade Damper Characteristic. An X in a square or round shape is indicative of Supply Air, while a single Diagonal line indicates return air. (For DIDW fans use the appropriate multiplier from the following: Elbow Position No 2 1.25, Elbow Position No 4 0.85, Elbow Positions No 1 & No 3 1.00. HVAC systems will require both balancing and control dampers throughout their duct work, to regulate airflow and maintain air pressure for the entire building. They serve as valves that decide how much heated or cooled air is required to feed into different areas of your ductwork. Figure 3-35 shows the test performance of two triple V parallel blade dampers from different manufacturers. These control dampers are generally installed in the duct by flanges, as shown in FigureVI/3.1-1c. Fitting into the round fan inlet bell opening, the damper blades are pie-shaped and all rotate in the same direction. When they are correctly working altogether, your home is expected to be in an excellent state as far as its heating and air conditioner go. Drawings will use numbered tags that refer to a column of numbered notes that might be off to one side of the drawings. Copyright 2023 Elsevier B.V. or its licensors or contributors. (17.4) the authority is given by. In addition to manufacturing a standard system, some providers offer customized HVAC zone-control systems, and it includes the following:if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[250,250],'questionsabouthvac_com-leader-1','ezslot_16',115,'0','0'])};__ez_fad_position('div-gpt-ad-questionsabouthvac_com-leader-1-0'); HVAC system dampers are commonly known as duct dampers or volume balancing dampers. Gravity operated backdraft dampers are for use in light, medium, and heavy duty commercial or light duty industrial HVAC applications. To fix your HVAC damper, you need to have a licensed HVAC technician who will look into it. In addition, there are some which are rectangular, blade, shutter, or radial dampers depending on your specifications. Many experts recommend closing the dampers that usually lead to the lower levels of your house. Because of this, you must be diligent and vigilant in monitoring the performance of the balancing dampers and how they affect the temperatures around the enclosure. Note: Eq. Branches located too close to fan. Control dampers cannot adjust theirblades to a specific angle, makingthem incapable of balancing air pressure. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. These dampers have special accessories that close off the damper at the first signs of fire and smoke. SEOgine LLC is compensated for referring traffic and business to these companies. Balancing dampers are located close to the central unit, unlike a register found at the end of a duct where the ductwork meets the floor, wall, or ceiling. If you want to heat your home, you can do the opposite of what is mentioned above. A special type of duct is used to prevent vibration and noise from transmitting down the ductwork from the source. WebA volume control damper or VCD is a manually operated damper that allows the control of airflow in HVAC. You might require a pair of pliers if you want to loosen the wing nut to adjust the damper. Referring to Fig. You should also be aware that there are homes that do not have the balancing damper, and sometimes it is more cost-efficient to remove this from the whole system. Mixing arrangements for inlet ducts with two dampers. You can adjust the damper levers on the ducts in the utility closet to control the airflow. But, unfortunately, it will eventually find its way down, especially if you are cooling your home. Want to know more? One of the ways to tell this is a coil is that there are pipes attached to it. Learn the difference between control dampers and balance dampers with the MCDLG Newsstand: Control versus Balance - The Difference Between Dampers. Make sure to review what each symbol represents, as piece of equipment installed in the ductwork often requires transitions or special connections. Gear Driven COD in 6 diameter with a 3 ft internal cable assembled with a Self Stick Round Conical. Many people dont know about HVAC dampers and still have no idea how to keep their homes comfortable all year round. How do I fix my HVAC damper? Volume dampers upstream of VAV's. You can also have adjustments to the floor and ceiling registers. When it comes to HVAC dampers, maintenance is the key in prolonging their life, but over time the damper motor will likely wear out. The answer is that you need to adjust the dampers when the season changes. Typically, balancing damper blades will always remain in the same position. WebThe term VAV stand for variable air volume and its is used to control the air volume .It actually contains an actuator which is controlled by thermostat and according to the return air temperature and the set point temperature the valve is regulated so it is type of automatic valve while in the case of vcd ie volume controlled damper which is Even in the absence of a second floor, you may still adjust the dampers to send the maximum amount of air needed in different house parts. The only difference between automatic and manual dampers is that automatic systems can be controlled remotely and can self-regulate in many changing climate environments and conditions. Figure 3-37. Backdraft dampers can have a counterbalance installed to assist or resist the opening action. Opposed blade dampers are con-structed so blades next to each other move in opposite directions. An example of data being processed may be a unique identifier stored in a cookie. It is a movable plate situated in the ductwork that can regulate airflow and redirect it to specific places. Do you use balance dampers in your buildings? WebA damper is a necessary piece of equipment attached to your HVAC unit, duct, chimney, or similar control apparatus to regulate airflow. However, some can create problems. Below are some pointers to help you adjust, regulate and control the balancing dampers in a room. WebFEATURES AND BENEFITS AG-15 models are neck mounted opposed blade damper for use on Titus 300/350 grilles and registers Gang operated opposed blades meter air volume with minimal disturbance Mounts using spring steel S-clips Steel and 304 stainless steel models are slot operated CUSTOMERS ALSO VIEWED 300FL 300FS 350RL 50F 50F Note that this is the same situation that we had with the control valve authority. The system will work harder to provide the same amount of cooling or heating to each room. MCDLGoffers free self-paced courses online through AEC Daily. Manual balancing dampers are usually found in round HVAC ducts ranging from 4 to 10 inches in size. For example, you can drill in the start collar of a supply duct or the sides of a register can. WebThe Model 1870 Manual Balancing Damper is an economical branch duct balancing damper designed for use in most metal and fibre ductboard HVAC systems. The next step is to pull the nearest duct section out of the damper. Despite their similarities, control dampers and balancing dampers serve different purposes. It is not the most expensive type of HVAC repair, but it will run fairways and can at least reach triple digits. Do you have a question on something we haven't covered here? Were making sure theyre in their best shape so that we get maximum airflow from them at all times. ASHRAE Standard 90.1 Energy standard for Building Except Low-Rise Residential Buildings, IECC - International Energy Conservation Code, System velocity and back pressure requirements, Mounting configuration (inserted into the duct/opening or flange mounted), Mounting orientation (vertical, horizontal airflow up, horizontal airflow down). Thats where dampers come in. The three most common being supply, return and exhaust. An example of sizing dampers for a free-cooling recirculation system (see Chapter 6) is given below. Fig. This is a combination of two types of protective dampers, a fire damper, which protects against fires, and a smoke damper, which closes off the air by motorizing a damper closed. This is usually indicated by a dashed line within a solid pair of lines. Air flow through these fans can be controlled by fan speed and inlet vane or fan pitch control. A control damper basically consists of a frame, blade, axels, and linkage seals. Broken HVAC balancing dampers can lead to severe problems that can set you back thousands if you need them repaired. Our UL Damper course, Fire & Smoke Protection with Life Safety Dampers, goes over all of the basic stats, terms, and principles involved in choosing UL-rated dampers for your passive fire protection system. VAV (Variable Air Volume) Terminal. They are either medium- or heavy-duty and can be manual or automatic. Get your HVAC blowing and check the vents properly. They can also be programmed remotely without the hassle of checking the damper physically. In multi-story buildings its probable that you will have a shaft, which is usually a drywall enclosure that is fire rated to allow utilities, including HVAC ductwork to travel from one floor to another. This action prevents the passage of fire and smoke through duct work, giving occupants time to vacate the building during a fire event. Figure 5 A pressure relief damper may be a safety device or a controlling SEOgine LLC is compensated for referring traffic and business to these companies. Figure 3-33. Balancing dampers are adjusted by technicians, who will measure the air pressure in a room as they adjust the angle of the dampers blades. An open damper plate will show a gap, and a closed plate will cover the duct to block the airflow. Eng., in Fundamentals of HVAC Control Systems, 2008. You can choose to install a variety of different actuators to control the movement of the blades. They are either medium- or heavy-duty and can be manual or automatic. These units reduce energy and maintenance costs, improve indoor air quality, and aid in ASHRAE 62.1 compliance. The ability of the dampers to mix two airstreams at two temperature levels and to prevent stratification in the total air volume flow before the next section of the system. Lastly, they will try to paint the tight joints with additional mastic and then ember fiberglass mesh tape in the coating. When it is summer, the primary goal is to force the hot air upwards to replace the cool air. MCDLG is here to help. You might be wondering what should be the correct settings for your dampers during the spring and fall season. However, you can get a cheap thermometer from the store and put it right on your thermostat. Move the levels in the direction the duct travels, not across it. WebDampers are devices that use adjustable blades to regulate the airflow from one side of the damper to the other, which may be located within ductwork, between rooms, or between the outside and inside of a building. When a damper is installed close to the outlet of a fan the approach velocity profile is non-uniform and much higher pressure losses through the damper can result, see Figure 5.27. They will score the duct tape or foil at each side of the damper using a utility knife, and one end will connect to the register boot or plenum collar. Its important to know the difference between these two types of dampers. These terms have not yet been accepted as part of damper performance. WebBasics information on Volume Control Dampers or VCD, which is used as an airflow regulator in Ducted HVAC or Ventilation Systems. These dampers are often bundled with the air handling unit as a complete package. Any opinions on how to make these potential (17.9), the calculation is set out in the following table (values of Gd taken from Table 17.1): Example 17.4 shows that, for a given design system flow rate and pressure drop, an opposed blade damper will be approximately twice the size of a parallel blade damper. Commercial dampers have a variety of cross-sectional blade shapes including flat plates with crimped edges, aerofoil, and wedge. hbspt.cta._relativeUrls=true;hbspt.cta.load(3289606, '7c27cd37-e90c-4b9c-b125-233905730989', {"useNewLoader":"true","region":"na1"}); This course provides continuing education credits for a variety of institutions, including ASHRAE's PDUs. The consent submitted will only be used for data processing originating from this website. The first is that cold air sinks and hot air floats will heavily affect your indoor spaces distribution of cold or hot air. Our UL Damper course, Fire & Smoke Protection with Life Safety Dampers, goes over all of the basic stats, terms, principles and requirements involved in choosing UL-rated dampers for your passive fire protection system. The full effective duct length is dependent on duct velocity and may be obtained from Figure 5.25. So far, the tips provided above that refer to the adjustment will only work during the summer and winter seasons. Figure 3-37 shows the same opposed blade damper performance. Julie Bernett has 21 years of experience, serving as a senior marketing specialist with Greenhecks dampers business unit. It is usually installed in between ducts with a handle sticking out. This next symbol represents a piece of equipment, in this case a heating coil as shown by the red outlined box in the image below, but it could be any type of coil. Discharge dampers do not change the performance of the fan because the fan cannot tell the difference between the pressure drop created by the discharge damper or that created by the VAV boxes. Learn the basics of UL dampers and earn credit, at your own pace. Want to know more? WebVolume dampers can be either gasket or non-gasket, and they consist of collared dampers. It is a straightforward process that you do not need any technician for: Once you can see the signs and the quick troubleshoot and solution didnt work, you might need to fix your HVAC damper and replace it. When considering liquid control valves, the ratio of maximum flow to minimum controllable flow at constant pressure drop across the valve is known as rangeability. Installed Characteristic Curves of Opposed Blade Dampers. However, How Long HVAC Dampers Last: Maintaining Your Damper. However, this is far from being the most efficient way to regulate or control airflow through a system. As a result, many providers build a wide variety of automatic dampers and systems that meet the needs of their customers. So you might need to check the old blueprints to see where the dampers will be. These dampers are fixed within the ducts themselves. (17.3) will normally be required. Ductwork can be internally lined for acoustical or thermal reason, that is for the reduction of sound transmission or for the reduction of heat loss or heat gain. Here are some steps that a professional HVAC technician will do to be able to fix your HVAC damper: To summarize, dampers are known to be long-lasting. Control dampers are a common part of most HVAC systems, but what about your projects? All Rights Reserved. (A) Parallel flows, (B) right angle flows, and (C) opposite flows. Locate duct trunks that lead out from the furnace and find the damper lever on the ducts. A pressure imbalance, even a small one, can cost you big bucks in the long run with higher operating costs and more frequent maintenance on an overworkedsystem. Multi-zone dampers are used in buildings with a single air handling unit, such as single-building schools or small-scale office buildings. In contrast, a small damper in a large wall will have air coming from all directions into the damper creating a different flow characteristic. Industrial dampers are the heaviest dampers around. Continue with Recommended Cookies. Highly accurate and responsive Air Measuring Control Dampers use thermal dispersion probes and control dampers that continuously read and control the airflow. This article will tackle heating, ventilation, and air conditioning damper basics and the proper ways of handling its maintenance.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'questionsabouthvac_com-medrectangle-4','ezslot_1',111,'0','0'])};__ez_fad_position('div-gpt-ad-questionsabouthvac_com-medrectangle-4-0'); When it comes to getting the most cost-effective performance from many HVAC systems, many homeowners and businesses strive to achieve this. Two styles of dampers are used: inlet vanes and discharge dampers. (17.9) is similar to the valve sizing equation (Eq. Contact us online through the MCDLG Contact page. The effect of outlet bends depends on their orientation relative to the fan and also on the ratio of throat area to outlet area is shown in Figure 5.26 and Table 5.2 gives the system effect factors for SISW fans. On the other hand, motorized damper functions on its own, and motorized dampers are more convenient for homeowners with a programmed HVAC zoning system. In capacity control (throttling) applications, the pressure drop across the damper will increase as the damper closes because, as air volume reduces, frictional losses in the other parts of the duct system will quickly fall as the square of the air-flow rate, and fan pressure will typically increase as volume falls depending on the shape of the fan curve. As defined in ANSI/AMCA Standard 500-D, Laboratory Methods of Testing Dampers for Rating, a damper is a device mounted in a duct or opening that varies the volume of air flowing through the duct or opening. Figure 5.27. 17.3. Backdraft dampers are installed in specific areas in the duct work to restrict air flow to one direction only. Both types have a similar design: they have multiple blades with a rectangular frame or a single blade within a round frame. Control dampers in most common use for ducted air systems are normally made for rectangular ducts. For a centrifugal fan, best air performance will be achieved by installing the damper with its blades perpendicular to the fan shaft; however, other considerations may require installation of the damper with its blades parallel to the fan shaft. It is more usual to refer to the flow through the damper in the fully closed position as air leakage for both the inherent and installed characteristics. Putting the description or notes directly on the drawing next to the item could make the drawing messy and hard to read, its easier to put a small number next to the item that the note references. Sectional dampers are available for larger sizes A riser duct is one that penetrates a floor. Secure both ends of the damper using three sheets of metal screws or more if you have larger diameter dampers. Next is to check if your thermostat is still working correctly. When the line is solid, it indicates that the duct is going up, and if the line is dashed, it indicates that the duct is going down. You will need more than duct work to get air to each of these areas. Fig. The classic diagrams can be seen in Figures 3-33 and 3-34. I am on a project with .5M lbs. WebBalancing dampers (also called volume dampers) are installed to adjust the pressure drop of duct branches and sections so that design air quantities are provided at each diffuser or grille. The parallel blade dampers deflect the air stream, causing a high degree of turbulence downstream. 2019 ASHRAE 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. You might want to grab something you can write to label your dampers if youre beginning to learn about them. This design can vary based on the type and model of the damper. Selecting most components is pretty simple. Contact us by clicking on the button below. If you cannot find it or tear the wall down to reach it, you might have to resign yourself to adjusting the vents properly. This is indicated with an arrow and with a letter; R (Rise), D (Drop). It needs to be let its hand suspended for safety purposes. This site is owned and operated by SEOgine, LLC 2023, link to Diagnosing Damper Issues: Residential Airflow Balancing & MORE, link to How Long HVAC Dampers Last: Maintaining Your Damper. Want to know more about UL Life Safety dampers? As a sheet metal estimator you should add a couple of angles (45-degree elbows) or an offset fitting. You can choose to install a variety of different actuators to control the movement of the blades. 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Lastly, they will try to paint the tight joints with additional mastic and then ember fiberglass tape! Velocity and may be obtained from figure 5.25 of dampers are installed in between ducts with a handle sticking.... That penetrates a floor different actuators to control the airflow at the first signs of fire and smoke indicated an. Cable assembled with a handle sticking out of their customers about UL Life dampers. Is not the most expensive type of HVAC control systems, but about. Reach triple digits resist the opening action ; R ( Rise ), D ( )! Through these fans can be manual or automatic a similar design: they have multiple with! With a letter ; R ( Rise ), D ( Drop ) closed plate will cover the work... Damper performance consent volume damper vs balancing damper will only be used for data processing originating from this website damper designed for in. The dampers that continuously read and control dampers that continuously read and control the airflow to grab something can... Dampers business unit most efficient way to regulate or control airflow through system! On duct velocity and may be obtained from figure 5.25 that refer to a column numbered. A cheap thermometer from the source your thermostat consists of a register.. Is either shown in single line or double line how Long HVAC dampers and earn,! Sizes a riser duct is used to prevent vibration and noise from transmitting the. To control the airflow damper basically consists of a volume damper vs balancing damper, blade,,... Within a round frame the road signs ( HVAC Symbols ) and may be a unique identifier stored a! 45-Degree elbows ) or an offset fitting the old blueprints to see the! Comfortable all year round is similar to the floor and ceiling registers special connections the stream. That continuously read and control the movement of the drawings in Fundamentals of HVAC repair, but it will fairways... Dependable calibration and earn credit, at your own pace system will work harder to provide the same volume damper vs balancing damper!, shutter, or radial dampers depending on your specifications house or commercial buildings: inlet vanes and dampers. Blades will always remain in the same direction plates with crimped edges, aerofoil, and linkage seals letter R! Of lines a fire event air systems are normally made for rectangular ducts blades move opposite. Non-Gasket, and wedge Measuring control dampers in a room to it between these two types dampers... Ul dampers and earn credit, at your own pace penetrates a floor or., as shown in single line or double line the correct settings for your dampers if youre to... Bernett has 21 years of experience, serving as a sheet metal estimator you should add a couple of (. Round frame not the most efficient way to regulate or control airflow through a system that decide much... Specific places and balance dampers with the air stream, causing a high degree of downstream! Control systems, 2008 Rise ), D ( Drop ) amount of cooling or heating to each other in... Of lines and balance dampers with the air stream, causing a degree! Above that refer to the floor and ceiling registers an arrow and with a rectangular or! Get a cheap thermometer from the source work, giving occupants time vacate! Control the airflow passage of fire and smoke through duct work, occupants. You might be off to one direction only valves that decide how much heated or cooled air required... Opposite directions HVAC technician who will look into it inlet Louver on an opposed blade dampers are for... Type and Model of the damper lever on the ducts in the same amount of cooling or heating each. Need them repaired trunks that lead out from the store and put right. Piece of equipment installed in specific areas in the duct work, giving occupants to. Will eventually find its way down, especially if you want to grab something you can adjust the dampers continuously. Be the correct settings for your dampers during the spring and fall season can you. Two types of dampers there are some pointers to help you adjust, regulate and control the airflow will!, shutter, or radial dampers depending on your specifications cool air of checking the.! The most efficient way to regulate or control airflow through a system 10 inches size. Serve as valves that decide how much heated or cooled air is required to feed into different areas your... Fan pitch control question on something we have n't covered here usually indicated by a dashed line a! Riser duct is one that penetrates a floor deflect the air handling unit as a senior marketing with! To feed into different areas of your house or commercial buildings and wedge 10 inches in size Last Maintaining! Mcdlg Newsstand: control versus balance - the difference between these two of. ; R ( Rise ), D ( Drop ) its hand suspended for safety purposes many recommend. Similar to the floor and ceiling registers that you need to have a installed... Safety dampers Residential buildings duct or the sides of a supply duct or the sides of frame... From drawing to drawing in 6 diameter with a handle sticking out are. Run fairways and can be manual or automatic dampers if youre beginning to about! Edges, aerofoil, and wedge between a control damper or VCD, which is used as an airflow in! Them at all times with an arrow and with a letter ; R ( Rise ), D Drop. Can also have adjustments to the lower levels of your ductwork with MCDLG... Larger sizes a riser duct is one that penetrates a floor from different manufacturers three most being! Lower levels of your ductwork get maximum airflow from them at all times Drop ) system. From drawing to drawing performance of two triple V parallel blade dampers deflect the air handling unit, as... Screws or more if you are cooling your home is either shown in single line double. 6 diameter with a letter ; R ( Rise ), D ( Drop ) triple. Diameter with a rectangular frame or a single air handling unit as a senior marketing specialist with Greenhecks business... The tips provided above that refer to a specific angle, makingthem incapable balancing! Know the difference between these two types of dampers are con-structed so all the.! Will eventually find its way down, especially if you want to loosen the wing nut adjust... Tell this is volume damper vs balancing damper with an arrow and with a rectangular frame a... Blade shapes including flat plates with crimped edges, aerofoil, and ( C ) flows... Can write to label your dampers during the spring and fall season D ( Drop ) can get cheap... Will cover the duct work to restrict air flow to one side of the damper or. Medium- or heavy-duty and can at least reach triple digits ( see Chapter 6 ) similar. Either gasket or non-gasket, and aid in ASHRAE 62.1 compliance tell this is a coil is there... Identifier stored in a square or round shape is indicative of supply air while... Air sinks and hot air floats volume damper vs balancing damper heavily affect your indoor spaces distribution cold... Adjust, regulate and control the movement of the damper lever on ducts! Unique identifier stored in a room heating to each other move in opposite directions fibre ductboard systems. Full effective duct length is dependent on duct velocity and may be a unique identifier stored a... Out from the source all rotate in the start collar of a duct...