If you need product or project advice, technical support, or have any other questions, we're here to help. AHRI uses cookies to ensure that we give you the best experience on our website. Systemair KA units are designed as a modular air handling units from as small as 1.000 m3/h up to 100.000 m3/h. The next level of AHUs could be considered semi-custom, highly flexible, but cataloged, AHUs that can be selected to meet most any commercial, institutional, or even industrial applications. If condensate blocks part of a steam coil, one part of the coil will be warm and another will be cool. Dependent upon the existence of a BAS, this monitoring can also be done by using a visual display from a simple magnehelic differential pressure gauge, or by a pressure switch linked to an input (I/O) alarm point. The HVAC load capabilities of these units generally range from a few thousand cfm to tens of thousands. Eurovent certified KA units are available in different versions and meet both comfort requirements as well as the most demanding ventilation needs. They can be modified for the higher hygiene requirements in certified hygienic execution or outdoor execution, where units can be exposed to the external weather conditions. 382 0 obj
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Slightly larger AHUs selected for outdoor use, located on grade outside or on the roof, are usually referred to as packaged units or rooftop units (RTUs), respectively. Custom AHUs are often used in applications such as laboratories, large industrial and manufacturing facilities, or in renovations where a semi-custom unit cannot fit. %PDF-1.7
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46 standard sizes with additional 14 sizes for larger units. Jtzl*kxg,D':(jX'S!Gt
*RU0hy7[0FoIjg~wBTHy~\T?BZqf`qPCJ~eyzU|>=G0Mv'=>)RawwQ Ik8Lp+AAb;! The function of each set of filters is to help extend the life and improve the efficiency of the next set of filters. H]o0#?K:ivLU%RcvAw'XASTyH ysH$ \/ Courtesy: Stanley Consultants Inc.[/caption]. 409 0 obj
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\LN[/M5bmtd+Z~Ye5)E,Dbbv ZfRNzzQDT-J$yf;|W.T3G/CO|S]o'Q?l{d '#W/x]9xY ?fnb%pT[=6o~csn These cookies will be stored in your browser only with your consent. deep type, based upon the application for which they are needed in the AHU. Depending upon the manufacturer and size of the AHU, the framing system can be constructed from metal c-channels or square steel framing, with internal wall posts and sectionalized steel base rails under the unit. Custom air handlers are generally used in large systems over 50,000 cfm. For example, ANSI/AHRI Standard 430-2014 defines a central station AHU (CSAHU) as a factory-made encased assembly consisting of a supply fan, or fans in parallel, which may also include other necessary equipment to perform one or more of the functions of circulating, cleaning, heating, cooling, humidifying, dehumidifying and mixing of air.. In addition to the components noted above, these units will typically have control dampers and serve larger areas or multiple zones within a building. cNa~b A!
There are several basic things to know about coils. 396 0 obj
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The framing system can be bolted and/or welded together with gaskets and joint sealants used between important contact points. Terms of Use | Terms of Sale | Privacy Policy | Do Not Sell My Personal Information, Additional information on indoor central air handling units, For more information on construction leads, call, Modular Indoor Central Station Air Handling Units, Custom Indoor Central Station Air Handling Units, Indoor Indirect Fuel Fired Heating & Ventilating Units, Indoor Direct Gas Fired Heating & Ventilating Units.
Classification for HVAC air filters confirms that the filters will meet local and state requirements for most applications, and particularly in accordance with the standards of the NFPA. Multi-zone air handlers have additional sections containing separate components. Typically, the HVAC ductwork system returns some, if not all, of the return air (RA) back to the AHU; however, AHUs can simply supply and return air directly to and from the space they serve with very little or no ductwork. *If rated according to AMCA Standard 207 Method. This category only includes cookies that ensures basic functionalities and security features of the website. Central Station Air-Handling Unit Supply Fans. KA units can be modified to fit into almost any space. The length depends on the: built-in functional elements, purpose of use, installation type, position of the intake and exhaust section and any special customer requirements. A designer can select a coil that is not counter-flow, but the coils performance will be reduced, based on its size, by anywhere from 8% to 12%. Filters should also be Underwriters Laboratories Inc. (UL) classified. Quick selection and thermodynamic calculation of the unit can be made in airCalc++. 0
As HVAC designers, providing a system that can meet the building comfort requirements at a reasonable cost while minimizing maintenance costs and energy use, is the primary goal. Heating and cooling coils have both rating and testing standards by AHRI Standard 410 Forced-Circulation Air-Cooling and Air-Heating Coils and ASHRAE 33 Methods of Testing Forced-Circulation Air-Cooling and Air-Heating Coils. In this way large air handlers can be custom manufactured to suit particular applications. There are other types of filters such as chemical impregnated gas-phase as well as electrostatic and ultraviolet for air treatment requirements. Figure 3 is an example of a preliminary AHU elevation selection that illustrates the various physical internal components for a dual duct AHU with multiple plenum fans. Feeding the coil header from the top will typically cause some level of short circuiting with higher water flow in the tubes at the top in the coil. other content relating to indoor central-station air-handling units as well as other For cooling coils, they are built to be piped in a counter-flow arrangement; or, the air flows in the opposite direction as the chilled water (CHW), and/or the refrigerant in DX coils. Coils are primarily constructed of tubes, typically of copper, with copper or aluminum fins pressed or extruded on the external surface of the tubes for several heat transfer processes. How to reach sustainability in data center? In applications with more than one set of filters, a preliminary or rough grade filter would be provided first in the direction of airflow. In addition, AHU appurtenances are equipment or components that may be added to an AHU for purposes, including but not limited to, control, isolation, safety, static pressure regain, and wear. In particular, the dehumidification capabilities for the coil are significantly reduced. There also may be several other components used such as energy recovery devices that could be employed to assist in the processes. Fiberglass insulation can be laid into the panel voids prior to closure, or with recent construction methods, sprayed in as a foam product that then dries and adheres to the metal. The sides or wall panels can be single or double skin insulated metal panels. As an example, assume an AHU supplies 100,000 cfm using a 125 hp SF, the fan heat is calculated as: 125 hp = (0.746 kW/hp) x 3,413 Btu/h/kW = 318,262 Btu/h. Other references a designer should review are AMCA 511 Certified Ratings Program Product Rating Manual for Air Control Devices and ANSI/AMCA STANDARD 500-D-2012, Laboratory Methods of Testing Dampers for Rating. Likewise, an interior area comprised of multiple work spaces or cubicles within the building also could be considered a larger HVAC zone. of static pressure, and shall be AMCA (Air Movement and Control Association International Inc.) licensed as a Class 1A damper. The result of performing a variety of these HVAC processes is the delivery of properly conditioned supply air to the spaces it serves. Filters can be a variety of types and sizes, from throwaway 2-in.-thick type through reusable 36 in. In fact, ASHRAE Standard 90.1-2016 defines an HVAC zone as a space or group of spaces within a building with heating and cooling requirements that are sufficiently similar so that desired conditions (e.g., temperature) can be maintained throughout using a single sensor (e.g., thermostat or temperature sensor).. hb```*fAd`0p, Fan efficiencies, sound levels, and redundancies are also considerations in fan selections. The filter frame is generally built to accommodate standard size filters (e.g. Intelligent ventilation systems and digital aids, Air conditioning of nurseries and schools, Windefalk Ventilation - Injusteringsverktyg. By monitoring the pressure drop through the filters, as related to the airflow through the AHU, the filter life can be assessed and decisions can be made regarding the appropriate time to change them. Review our, 2016 ASHRAE Handbook HVAC Systems and Equipment, Air-Conditioning, Heating, and Refrigeration Institute (AHRI), AHRI 106 Performance Rating of Air-to-Air Exchangers for Energy Recovery Ventilation Equipment, ASHRAE Standard 84-2013 Method of Testing Air-to-Air Heat/Energy Exchangers (ANSI Approved), ASHRAE Guideline 16 2014 Selecting Outdoor, Return, and Relief Dampers for Air-Side Economizer Systems, AMCA 511 Certified Ratings Program Product Rating Manual for Air Control Devices, ANSI/AMCA STANDARD 500-D-2012, Laboratory Methods of Testing Dampers for Rating, AMCA (Air Movement and Control Association International Inc.), AMCA 610 Laboratory Methods of Testing Airflow Measurement Stations for Performance Rating, and AMCA 611 Product Rating Manual for Airflow Measurement Stations, ASHRAE Standard 62.1-2013: Ventilation for Acceptable Indoor Air Quality, ANSI/AMCA 210 Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating, AMCA 300 Reverberant Room Method for Sound Testing of Fans, 2016 ASHRAE Handbook HVAC Systems and Equipment, Chapter 21, Fans, 2016 ASHRAE Handbook HVAC Systems and Equipment, Chapters 23 and 27, AHRI Standard 410 Forced-Circulation Air-Cooling and Air-Heating Coils, ASHRAE 33 Methods of Testing Forced-Circulation Air-Cooling and Air-Heating Coils, Exploring sustainable grocery refrigeration systems, Webcast: How to specify HVAC motors, drives to meet energy goals, Trends, changes in data center HVAC design, Webcast: Pairing VRF with applied HVAC solutions. The HVAC systems AHU fans (SF, RF, exhaust fan or EF) considered should be based upon the desired design operation point for the airflow required and at the static pressure of the system. These modules can be stacked or arranged in a variety of configurations to address a projects constraints (i.e. <> Find AHRI Certified Central Station Air-Handling Unit Supply Fans. There is no need to fully open or fully close a damper (except in emergencies or when off-line), and splitting the OA damper will help limit the dampers to their respective portions and can be used for controlling the required airflows more efficiently. Most manufacturers have a line of these type of AHUs, which can be modified to meet a designers specific job requirements for new or existing building projects. dJ@ql`~?f:nAw{o= #0!n.;cx@.t@kP::2 LZcw`+e"*GJ$@ @+Kb'grB}C#SBPr,\e+
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Automatic Commercial Ice-Makers and Ice Storage Bins, Central Station Air-Handling Unit Casings, Commercial Refrigerated Display Merchandisers and Storage Cabinets, Forced Circulation Air-Cooling & Air-Heating Coils, Geothermal Direct Geoexchange Heat Pumps, Liquid to Liquid Brazed & Fusion Bonded Plate Exchangers, Non-Condensable Gas Purge Equipment for Use with Low Pressure Centrifugal Liquid Chillers, Variable Refrigerant Flow (VRF) Multi-Split Air Conditioning and Heat Pump Equipment, Water-Cooled Water-Chilling and Heat Pump Water-Heating Packages Using the Vapor Compression Cycle, Annual Sales Volume Reporting Instructions, Central Air Conditioners and Air-Source Heat Pumps, Commercial Storage Water Heaters Historical Data, Residential Storage Water Heaters Historical Data, AHRI Low-GWP Alternative Refrigerants Evaluation Program, AHRI Flammable Refrigerants Research Initiative, Refrigerant Policy and Regulatory Resources, Comprehensive Energy Efficiency Regulations, United States Environmental Protection Agency, International Agreements for Refrigerants, Canada Energy Efficiency and Refrigerant Regulations, Navigating Compliance at the Department of Energy, Product-Specific Operations Manual (Dec 20), Product-Specific Operations Manual (Dec 21), Air Conditioning, Heating, and Refrigeration Institute, Privacy Policy Do not sell my information. Note that with a draw-through fan arrangement, this example shows that the fan leaving air temperature will be higher than the cooling coil leaving air temperature by almost 3F. An HVAC systems AHU may contain other components necessary to perform a combination of the four basic psychrometric processes of cooling, heating, dehumidification, and humidification. For example, in a semiconductor manufacturing plant, custom AHUs might be sized at 200,000 cfm with a 150 hp motor on the fan, and have a preheat coil, a primary and secondary chilled water coil, a glycol coil, a reheat coil, and a humidifier section to pre-condition and treat outside airstreams. Common appurtenances include, but are not limited to, coils, filters, energy recovery devices, dampers, air-mixers, spray assemblies, eliminators, discharge plenums, and inlet plenums. 9~9{C;Ag^vk3$(?A)?~Xsu0)j a?z
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?nGq?VKQ`=QvpGfsf\ B'd4ske{V_ 0`z'xU?+P&. The rules and procedures for obtaining and maintaining certification are detailed in the Resources section above. If you need any more information, please get in touch. AHU types, components, and configurations, By Randy Schrecengost, PE, CEM, Stanley Consultants, Austin, Texas, By using this website, you agree to our use of cookies. If you continue, we assume that you accept AHRIs usage of cookies. It is mandatory to procure user consent prior to running these cookies on your website. 1ZQuD8Jgf~gg'=#'=BV'Ou [Bmy 5$ v@%@N >=H 5z1=Fnga=rp=(x&a It shall not contain a source of cooling or heating other than gas or electric heat. To ensure the proper amount of ventilation or OA is provided to an AHU, many designers today add airflow measuring stations either in the OA ductwork (see Photo 2) or at the entrance of the mixing plenum with a combination damper and air flow measuring device. ?l\sA1\&eH#Q0aHH L5;'u#!yo[E9U)Uy:q\RI)e1G 4xiWB3(_+Y|O>VUU.JTu]$?e*]Vgq ~Qx'/+Qbh> db%6>cv5 nI~\=C6M(S% All AHUs will have a supply air fan (SAF, or SF for short). This mixing plenum and/or filter section of the AHU should have service access door(s) as well as differential pressure devices across filter assemblies for indication when the filters are dirty. The specific Standard listed above details the technical requirements for rating and publishing your product performance, the AHRI General Operations Manual (OM) details the program operational rules that are generic to all of AHRIs certification programs and lastly, the Product-specific Operations Manual provides the operational rules that are specific to this program along with the required documents and fees. (0tZ5~qx!{;yIo(eS,(AU@H 1HA H3d8Qa&CCL
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You should consider contributing to our CFE Media editorial team and getting the recognition you and your company deserve. Some installation requirements may represent a major challenge for the AHUs to fit perfectly. Manuals, brochures and other product literature. Designers should pay close attention to the location of the fan in relation to the AHU coils. You also have the option to opt-out of these cookies. An exterior row of three or four offices in a commercial office building, for example, may be considered a small HVAC zone because the occupant density and usage patterns are similar. They begin to be more defined in terms of total heating and/or cooling capacity, which are stated as Btu/h. Air Handling Units are manufactured assemblies of components (coils, filters, fans, humidifier, dampers, etc.) The ASHRAE Handbook-Fundamentals provides a general estimates of fan heat as approximately 0.5F per inch of total fan pressure. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. A custom AHU may be used if there are special application or capacity requirements for the project beyond standard manufactured equipment, there are physical size constraints, or abnormal inlet and outlet connections. 2018 ConstructConnect, Inc. All rights reserved. Mechanical properties in accordance with EN 1886: KA units are equipped with advanced and factory tested components such as fans (plug fans with EC or AC motors), heat exchangers (plate heat exchangers in cross and counter flow version, rotary incondensation, sorption and enthalpy versions, run-around coil), heating coils(water, electric, indirect gas), cooling coils(water, evaporative - DX), filters(from Coarse 65% (G4) up to ePM1 85% (F9) according to EN ISO 16890), protection equipment, control system, etc.. Components, such as electric cabinet, control and measuring devices (sensors, motor drives, differential pressure switches, thermostats, etc. Available in several executions such as standard, hygienic and corrosion resistant for indoor and outdoor installation with fully factory integrated control system. The roof can be like the sides of the AHU unless its in an outdoor application where additional weatherproofing and joint sealing may be required. Both parallel- or opposed-blade dampers can be used for controlling the overall proportions of the airstreams, but pressure relationships and sizing for wide-open and/or modulating pressure drops needs to be considered. The floor is typically insulated and covered with a thick metal plate, sometimes in a diamond pattern to assist in providing a walkable surface. The energy related components follow rating and testing requirements by AHRI 106 Performance Rating of Air-to-Air Exchangers for Energy Recovery Ventilation Equipment, and ASHRAE Standard 84-2013 Method of Testing Air-to-Air Heat/Energy Exchangers (ANSI Approved). The filters are placed within a filter holding frame assembly or racking system that could be configured as either flat, or of an angular bank arrangement. Special requests are always welcome for discussion. The desire of every user is a fully automatic operation of the air handling unit according to their needs. The first set of filters are typically the cheapest to replace and thus maintain, while succeeding sets are more expensive to replace. hbbd``b`fS56 g+Zb" +$aL S 3$0 $
The RA damper is then selected on the difference between the total design supply air and the minimum OA flow rate, and considered the maximum RA flow rate. By using this application we can provide useful information about the unit such as: The air you breathe is our responsibility.
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