The Ductwork and Dampers Equipment - Coursework Example

The Ductwork and Dampers Equipment Institution Course Date Abstract The report below explains an overview of the heating, ventilating and air-conditioning, HVAC system. Ductwork and damper that are part of the HVAC system are further put into details. The design and installation method are also emphasized to ensure the effective results. Keywords: HVAC, ductwork, damper, design, install. Heating, ventilating and air-conditioning is acronymized as HVAC. The HVAC enables thermal control in building and works with active electro-mechanical systems (Furst & Grondzik 2010). The primary objective of HVAC is to ensure survival during various seasons, for example, the cold winters. It also affects air quality and comforts that influences satisfaction, occupant health, and productivity. As the name suggest, the purpose of the heating system is to increase the thermal energy with the aim of adjusting to an individual air temperature level in a building. The ventilating system accomplishes its role by introducing air or eradicating air from space maintaining the air temperatures. The cooling system aids in retention of some selected air temperature by removing thermal energy from space. Besides, the cooling system (air-conditioning) accomplishes various objectives: control air circulation; control air temperature; control air quality; and control air humidity (Furst & Grondzik 2010). Balance point temperature is influenced by building enveloped design and internal loads characterize the exterior air temperature of the building. The HVAC, therefore, enables the balance in cases where the temperature rises outside the building; this will automatically affect the interior temperatures (Greenheck 2013). The call for equilibrium between the interior and exterior air requires the HVAC system whose principal parts are duct work and the dampers. The duct work contains the air while the damper distributes the air from one point to the other of the whole system. The effects of HVAC transmit from a single location at the central system to the various spaces requiring conditioning in a building. The commonly used media for transmission include steam, air, and water. An adequate supply of the media is distribution component based. Worldwide, the most common HVAC central system is an air-based system which aid in controlled air selection properties. Air being a poor heat transfer medium, ductwork distribution in buildings is essential to make the system efficient. The duct work (ducts) is employed to transfer air from the secondary or primary source to its destination that is the final delivery component. In the air-based system, an influent duct and effluent duct are essential to ensure supply and confiscate air. To ensure controlled distribution of air ductwork, containment of air is used. The ductwork systems are categorized as a low-pressure system or high-pressure system based on the static pressure. Also, it can be classified as a low-velocity system or high-velocity system based on air speed design parameters. The design for influent duct work is dictated to operate at low- pressure and low-velocity lest other need be. On the other hand, the effluent ductwork should be designed to have high pressure that enhances the loss of air appropriately (Furst & Grondzik 2010). Materials such as galvanized sheet metal, glass fiber, and plastics are used to make ducts. Insulation and containment in a single material commonly in a low-pressure system are achieved by the use of glass fiber insulator board. Spiral metal frame works wrapped with plastic are used in flexible ducts that are used to linkterminalormaindistributor with deliverydevices. The duct devices come with different shapes including rectangular or square, flat oval, and circular cross sections. Eachshape has its advantages depending on the available space. For example, a rectangular one has no problems when it comes to positioning. To minimize heat gain from warm plenums and unconditioned spaces, the influent ducts are insulated for that reason while the effluent duct is not insulated. The duck system consists of splitters, dampers and turning vanes. The dampers regulate the flow of air with an objective to balance the flows or amend the flow of air in reaction to changing building loads. Some specialized ampers like smoke dampers and fired ampers minimize the spread of smoke and fire via the air distribution system in a building. Turning vane sand splitters, on the other hand, work to reduce turbulence leading to decreased friction losses within the ductwork. Besides, they also reduce the noise released within the ducts (Furst & Grondzik 2010). The contact between the air flowing through the duct system results in friction losses which also occurs when the air passes through coils, filters, dampers, and diffusers. To overcome the friction losses, a fan help to supply the energy input and also to distribute air through the system (Furst & Grondzik 2010). In the central HVAC system, many fans are required: for exhaust air, forreturnair, andforairsupply. The fans differ in designs and capacities that could be axial or centrifugal that is electric motors driven. Duct system’s main objectives to be met include supply and removal of the correct measure of air from the space installed providing comfort. The benefits linked to the proper installation and design also include adequate air flow, high energy efficiency, long life equipment service, safer and healthier indoor air quality. Other benefits include less expensive equipment, fewer callbacks and less linkage of conditioned air. Economic concerns on energy consumption are also considered when using the HVAC system. The ASHRAE Standard applies Watt per cubic feet per minute, (cfm) to restrict the duct distribution system limit for fan power. Ensuring comfort and energy efficiency, guidelines are given in the ASHRAE and ACCA handbooks (Greenheck 2013). Among the guidance on duct design and installation are: room by room determination air flow and loads; the duct system is to be laid down on floor plan considering potential obstructions; the ducts should be sized with appropriate calculations e.g. ACCA Manual D calculations; balancing the system and many other guidelines. After installation of a ductsystem, it is crucial to perform a leakage test. An air tightness test aims at measuring and documenting the leakage amount in the duct system following particular pressure. Different methods can be used that include blower door subtraction method and pressure pan and blower door in leakage test. Calibration of airflow is also performed using a duct blaster. The calibrator measures both inside and outside leakage in total. As stated earlier, the dampers are linked with the duct to balances the air entering and moving out of the duct. The dampers are positioned in a variable air volume (VAV) box that modulates the airflow. Apart from regulating the air temperatures, it also accentuates the noise released from the AHU. Control dampers in HVAC system are categorized as commercial control and balancing (Greenheck 2013). Balancing dampers control air flow but cannot serve for automatic control or positive shut-off. These types of dampers are shipped together with a manualor a remote. However, the commercial control dampers overweigh the manual balancing dampers in that; they can be used as an automatic control or positive shut-off. The effectiveness of a damper according to the Greenheck’s standard construction depends on symmetric of the damper blade axis and blade width combinations. The advantages attached to the standards include increased mounting flexibility, increased free area, and minimal actuator torque. To enhance the strength of the blades, galvanization of steel is employed. For airfoil blades extruded aluminum heavy-gauge, stainless steel, or galvanized steel are used in high-pressure systems. Also, they influence increased strength and lower resistance to airflow (Greenheck 2013). Regarding the operation required for a damper, the blade can operate as paralleloropposed. In parallel blade operation, the blades rotate parallel to one another and in the same direction. This is applicable in two position orientated damper, closed and opened. In opposed blade operation, adjoining blades rotate opposite direction to one another and are used airflow dampers (Image Performance Institute, 2013). Failure to the two dampers to operate, air supply by the supply fan continues raising a risk of collapsing of the ductwork. Damper sizing if done properly relates to various advantages based on their convenience location and duct size. Such advantages include owner installation costs, reduced energy cost, improved linearity, and control characteristics (Image Performance Institute, 2013). Pressureandvelocity of airflow in HVAC must be adequateforany HVAC system to providecomfortandaccomplish its purpose. For example, during the summer seasons, moisture needs to be eliminated from space while in winter it needs to be added. Effective ductwork relates to a properlydesignedandinstalleddamper. Depending on the type of HVAC the duct system can be dual-duct or multi-zone HVAC system. A multi-zone system demands several air supply ducts separately while a dual system need to supply air ducts. References Greenheck, (Greenheck 2013) (Image Performance Institute, 2013) (Furst & Grondzik 2010) 2013. HVAC Control and Balancing Dampers. [Online] Available at: http://www.greenheck.com/media/pdf/catalogs/ControlDampers_catalog.pdf Image Performance Institute, 2013. The Fundamentles of HVAC: Suitable Performances Practice for Managing Storage environments. [Online] Available at: http://ipisustainability.org/pdfs/webinars/webinar_seriesii_april.pdf R, G. W. &., 2010. HVAC Components and Systems. [Online] Available at: http://vitalsigns.ced.berkeley.edu/res/downloads/rp/hvac/hvac-sml_opt.pdf Read More