lg flexline ahu ing
DESCRIPTION
LG AHUTRANSCRIPT
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Flexline Air Handling Units
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Contents
ABOUT US....................................................................................................................................................
1. CERTIFICATES...................................................................................................................
1.1. CE Mark.........................................................................................................................................
1.2. EUROVENT Certificate.......................................................................................................
1.3. Customs Union Conformity Certificate....................................................................
1.4. TSEK Certificate........................................................................................................................
1.5. ISO 9001 Certificate................................................................................................................
1.6. OHSAS 18001 Certificate.....................................................................................................
2. FLEXLINE STEEL FRAME AIR HANDLING UNITS..................................................
2.1. The Frame.....................................................................................................................................
2.2. Panel Structure..........................................................................................................................
2.2.1. Panel Insulation Material............................................................................................
2.2.2. Interior and Exterior Surface Materials..........................................................
2.2.3. Material for Panels and Corner Profiles...........................................................
2.3. No Thermal Bridging..............................................................................................................
2.4. Design Features and Advantages.....................................................................................
2.4.1. Test Results According to EN 1886...................................................................
2.4.2. Modular Design..............................................................................................................
2.4.3. Energy Efficiency............................................................................................................
2.4.4. Quick Selection Chart................................................................................................
3. FRAME DRILL TECHNOLOGY...........................................................................................
3.1. Assembly Steps..........................................................................................................................
3.1.1. Base Assembly................................................................................................................
3.1.2. Frame Assembly.............................................................................................................
3.1.3. Panel Structure...............................................................................................................
4. AHU PERFORMANCE STANDARDS................................................................................
4.1. EN 1886..........................................................................................................................................
4.1.1. Mechanical Strength of Casing.............................................................................
4.1.2. Casing Air Leakage......................................................................................................
4.1.3. Filter Bypass Leakage...................................................................................................
4.1.4. Thermal Transmittance..............................................................................................
4.1.5. Thermal Bridging Factor...........................................................................................
4.1.6. Acoustic Insulation of Casing.................................................................................
4.2. EN 13053.......................................................................................................................................
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5. COMPONENTS OF AHU............................................................................................................
5.1. Fans................................................................................................................................................
5.1.1. Fan Laws.............................................................................................................................
5.1.2. Plug Fan Section.............................................................................................................
5.1.3. Centrifugal Fan Section.............................................................................................
5.2. Coils.........................................................................................................................................
5.2.1. Coil Geometry................................................................................................................
5.2.2. Number of Rows..........................................................................................................
5.2.3. Number of Circuits......................................................................................................
5.2.4. Structural Properties of Coils...............................................................................
5.2.5. Testing of Coils..............................................................................................................
5.2.6. Cooling Coil.....................................................................................................................
5.2.7. The Drainage System.................................................................................................
5.2.8. Heating Coil......................................................................................................................
5.2.9. Electrical Heater.............................................................................................................
5.3. Heat Recovery Systems.......................................................................................................
5.3.1. Basic Principle of Heat Recovery.......................................................................
5.3.2. Rotary Type Heat Recovery.................................................................................
5.3.3. Plate Type Heat Recovery......................................................................................
5.3.4. Runaround Heat Recovery....................................................................................
5.3.5. Heat Pipe Heat Recovery........................................................................................
5.4. Filters............................................................................................................................................
5.4.1. Panel Filter.........................................................................................................................
5.4.2. Bag Filter.............................................................................................................................
5.4.3. Low Depth Filter...........................................................................................................
5.4.4. Carbon Filter....................................................................................................................
5.4.5. Rigid Filter..........................................................................................................................
5.5 Humidification Systems........................................................................................................
5.5.1. Steam Humidifier..........................................................................................................
5.5.2. Spray Humidifier............................................................................................................
5.5.3. Evaporative Humidifier...............................................................................................
5.6 Mixing Chambers.....................................................................................................................
5.6.1. Double Damper Mixing Chamber.....................................................................
5.6.2. Triple Damper Mixing Chamber.........................................................................
5.7 Attenuator Section..................................................................................................................
5.8 Damper...........................................................................................................................................
6. AUTOMATIC CONTROL SYSTEMS..................................................................................
7. AHU TESTING and PERFORMANCE MEASUREMENT (AMCA) CHAMBER......
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Contents
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SystemairSystemair was founded in 1974 in Sweden by CEO Gerald Engstrm, as a company pioneering in the development and market release of circular centrifugal fans that simplify HVAC systems.
Its manufactured products include fans, air handling units, air curtains, heating products and since 2012, cooling products.
The business percept of Systemair, which operates on the basic values of simplicity and reliability is based on developing, manufacturing, and marketing quality HVAC products.
Systemair has registered an operational profit every year since its founding. The average annual growth rate for the last 10 years is 15%.
Systemair Group;
Has made sales of 4.55 billion Swedish Krona in the 2012/2013 fiscal year,
Has registered an average growth of 15% in net sales over the last 10 years,
Has subsidiaries in 46 countries spread in Europe, North and South America, The Middle East, Asia and South Africa,
Has 19 factories with a total storage and manufacturing area exceeding 220,000 m2,
Has the highest credit score (AAA),
Is listed in the NASDAQ OMX Nordic Exchange,
Has 4,000 employees in 56 companies.
Systemair HSK is the one of the most modern factory of Systemair
Systemair HSKs new manufacturing facilities have become operational in February 2013.
The facility set on 30,000 m2 of outdoor and 12,000 m2 of indoor area predominantly manufactures air handling units.
Production in the Systemair HSK factory is carried out using a very special sheet metal processing machine found in a choice handful of AHU plants in Europe. The sheet metal processing machine that is set on an area of 1,500 m2 is a factory in itself.
With the Frame Drill technology developed by the Systemair HSK R&D team and patented by Systemair HSK, air handing units can be manufactured from standard parts and easily assembled in the field.
With the Air Handling Unit Performance Test Chamber (AMCA Chamber) housed in the facility, 1 in every 200 air handling units is tested for performance.
Air handling units, fan coil, heat recovery units are manufactured in the Systemair HSK factory.
About Us
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1. Certificates
Certification is a tool that documents that the product is safe and legal. It certifies that all specifications claimed for the products are guaranteed by an independent auditing company. Certified products also offer advantages in terms of delivery times to the customer, by offering easy passage through customs.
1.1. The CE Mark: LG has been using the CE mark on its air handling units since January 2003. The CE mark shows the products conformance to European product regulations. It is also a mark that enables free distribution of the product within the EU, whose use has become mandatory in the Turkish domestic market as of January 1, 2004. It is a declaration of warranty by the manufacturer as well as serving as a passport for a product, and indicates that the product will not harm people, the environment and other products in the same environment as long as it is used in accordance to its intended purpose. It is valid in product groups that fall within the boundaries of the union. Products are manufactured in adherence to basic requirements including effective EU guidelines.
1.2. EUROVENT Certificate: The Eurovent certificate, documents the performance classification of air conditioning and cooling product groups in accordance with European Union and international standards. LG has been awarded the Eurovent certificate following the tests performed in TV laboratories in Germany in 2001. Flexline Air Handling Units have successfully met the prescribed performance values in EN 1886 and were awarded with Eurovent Certified Performance logo.
1.3. The Certificate of the Customs Union (CU Certification): Is an official document confirming the quality of production to approved standards within the territory of the Customs Union. The Customs Union consists of three countries: Belarus, Kazakhstan and the Russian Federation. These countries have agreed on the sole basis of technical and regulatory rules. For products certified before September 2, 2011 (date of the official issuance of the Regulation), no action is required by the customer until the expiration date of their current Russia (GOST R), Belarus (STB) or Kazakhstan (GOST K) certificate approaches. GOST R, STB or GOST K certificates issued between September 2, 2011 and February 15, 2013 will be valid until March 15, 2015.
1.4. TSEK Certificate: LG conforms the Turkish Standards Institute (TSEK) for its products to the required standards. The TSEK comprises monograms that can be used within the framework of a contract, certifying that the products (or the packages of products) it is placed on has been manufactured and marketed in accordance with the Quality Factors and Values accepted by the Turkish Standards Institute. TSE EN 814, is used on labelled products which comply to TSEK and electrical specifications.
1.5. ISO 9001 Certificate: It is internationally accepted management standard which have been developed and implemented by the International Organization for Standardization (ISO), for constant improvement of efficiency and quality in management, production or service efforts, for fulfilment of customers conditions, and maximization of customer satisfaction through the introduction of certain conditions to the management systems of enterprises.
1.6. OHSAS 18001 Certificate: OHSAS 18001 is a generalized concept of work health and safety, including the protection of workers, of the enterprise and production from all sorts of hazards and damages. Due to the highest priority of human life, it views the issues of enterprise and production safety as a secondary priority, and indicates the safety of workers by the concept of work safety and health in the international area.
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2. Flexline Steel Frame Air Handling Units
LGs Eurovent Certified Flexline Air Handling Units offer high resistance to thermal leaks with their 50 mm panel design without thermal bridging, galvanized steel frame profiles that maximise the strength and durability of the air handling unit and their double sloped mineral wool insulated condensation pan manufactured as a standard from stainless steel.
Steel sheet thickness 0.8 mm 1.2 mm that has been galvanized against corrosion is used in interior and exterior surfaces. PVC frame and air handling unit edge profiles insulate against thermal bridging while offering an aesthetically pleasing appearance.
Frame profiles manufactured from galvanized steel sheets , with a thickness of 2 mm and with dimensions 30x30 mm and 30x60 mm form a structure that is resistant to negative pressure values. Connections of frame profiles are made with cast aluminium corner elements creating a rigid frame.
Connection of panels to frame profiles is made with screws that are protected against corrosion and preventing thermal bridging with protective covers and special sheaths. The modular nature of Flexline Steel Frame Air Handling Units offer solutions that may suit varying areas of application.
2.1. The FrameThe rigidity of the frame is increased by using 2 mm thick, 30x30 mm and 30x60 mm box profiles manufactured from galvanized steel maximizing the strength of the air handling unit under negative and positive conditions; which leads to a DI class the highest mechanical strength according to EN 1886. Profile connections consist of aluminium corner members. Connection of panels to box profiles is made with screws that are protected against corrosion and thermal bridging with protective covers and special sheaths. Special EPDM sealing is used in all connecting points of panels and profiles, to avoid thermal bridging and air leaks. Air handling unit cross sections are designed to match filter cross sections, in order to raise filter efficiencies and to ensure the required optimum speed values. Ergonomic filter mechanisms allow easy servicing of the filter. Thus the unit conforms to the highest EN 1886 filter by-pass leakage class of F9. Specially designed base frames function separately for each section and ensure that the weight of your air handling unit is transferred to the floor as a distributed load. Thus, a more stable and homogeneous load distribution is achieved on air handling unit bases.
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Frame profiles are manufactured of galvanized steel sheet.
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2. Flexline Steel Frame Air Handling Units
2.2. Panel Structure2.2.1. Panel Insulation Material
Panel thickness: 50 mmInsulation material: Mineral Wool
What is Mineral Wool?Mineral wool is produced by smelting and spraying rocks such as basalt, diabase and dolomite, mixing them with bakalite and subjecting them to special processes.
Mineral wool insulation material with a density of 50-70-110 kg/m3 can be used as an option in Flexline Steel Frame Air Handling Units.
Technical specifications for 50 - 70 - 110 kg/m3 mineral wool are presented in the following table.
2.2.2. Interior and Exterior Surface Materials
Interior and exterior surface metal sheets can be selected of galvanized steel, painted or stainless steel and be manufactured in the range 0.8 1.2 mm.
Painted metal sheets are manufactured from, primary surface with an epoxy coat of 5 and secondary surface is manufactured and 20 polyester oven based baked paint with colour code RAL 7035 secondary surface. A 80 of film is applied to protect exterior surfaces of painted metal sheets.
The amount of zinc used in galvanized steel sheets is 160 g/m2.
The quality class 304 2b is used as a standard in stainless steel sheets.
2.2.3. Material for Panels and Corner Profiles
Panel edge profiles are manufactured from PVC while corner profiles are manufactured from ABS material. Profiles are manufactured to offer high resistance against the effects of UV radiation. The range of operational temperatures is - 40 C / + 80 C.
50 kg/m3 70 kg/m3 110 kg/m3
UnitsValue or
StatementValue or
StatementValue or
Statement
Density / Dkg/m3 50 70 110
Tolerances 10 %
Thermal Conductivity W/m.K 0,035 0,035 0,035
Thermal Resistance / Rd (m2.K)/W 1,4 1,4 1
Fire Reaction Class Euroclass A1 A1 A1
Short Term Water Absorption / WS kg/m2
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Test Criteria of Casing Class
Mechanical strength D1
Air leakage L2
Filter by-pass leakage F9
Thermal transmittance T2
Thermal bridging TB2
2.3. No Thermal BridgingNo thermal bridging in an air handling unit indicates high resistance to thermal transmission between the inner environment of the air handling unit and the outer environment which there is a temperature difference. At this point, panel systems which separate the inner and outer environment of the air handling unit are very important. Since metal parts with high thermal transmission are insulated with plastic parts with low thermal transmission, the panel structure of Flexline air handling units display high resistance to thermal transmission between the inside and outside of the air handling unit.
Thermal bridging is an unwanted effect which raises thermal losses and lowers energy efficiency. Since it increases condensation risk, it causes corrosion on exterior surfaces, shortening the useful life of the air handling unit and increasing maintenance costs. Condensation on interior surfaces leads to corrosion as well as microbiological hazards.
Due to its superior design, the Flexline Steel Frame Air Handling unit has a very low thermal bridging value. It has been certified by Eurovent as TB2 class according to EN 1886.
2.4. Design Features and Advantages2.4.1. Test Results According to EN 1886
The Flexline Steel Frame Air Handling Unit with superior thermal and mechanical properties has been certified by Eurovent with the following thermal and mechanical specifications.
2.4.2. Modular Design
Modules are built on multiples of 306 mm. In this way, unit dimensions can be shortened and lengthened in modules. The modular structure also contributes significantly to minimising filter by-pass leaks.
2.4.3. Energy Efficiency
Flexline Steel Frame Air Handling units minimise thermal and pressure losses by virtue of their superior design. While excellent panel design prevents heat and air leaks, the aim is to minimise internal pressure losses by the correct layout of the equipment within the unit. Products are designed to offer minimum pressure loss within the air handling unit, through the CFD work carried our by the LG R&D team for this purpose. Hence, lower energy consumption is achieved. Flexline Steel Frame Air Handling Units offer a substantial advantage in energy efficiency since the Eurovent approved Rotary Heat Recovery System, Plate Type Heat Recovery System and Runaround Heat Recovery System can be easily applied and selected with in house designed air handling unit selection software.
Acoustic Insulation
125Hz 16,2 dB
250Hz 22,6 dB
500Hz 28,8 dB
1000Hz 29,0 dB
2000Hz 30,8 dB
4000Hz 35,3 dB
8000Hz 39,0 dB
2. Flexline Steel Frame Air Handling Units
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2.4.4. Quick Selection Chart
Flexline Air Handling Units can be manufactured in the air flow range of 2,000 m3/h to 100.000 m3/h. The suitable air handling unit casing can be easily selected as a function of the air flow rate and coil surface velocity using the following quick selection chart.
FL 100 x 110
FL 80 x 130
FL 100 x 100
FL 90 x 100
FL 90 x 90
FL 70 x 110
FL 80 x 90
FL 60 x 110
FL 80 x 80
FL 60 x 100
FL 70 x 80
FL 50 x 110
FL 60 x 90
FL 50 x 100
FL 70 x 70
FL 60 x 80
FL 50 x 90
FL 60 x 70
FL 50 x 80
FL 40 x 90
FL 60 x 60
FL 40 x 80
FL 50 x 60
FL 40 x 70
FL 50 x 50
FL 40 x 60
FL 40 x 50
FL 30 x 60
FL 40 x 40
FL 30 x 50
FL 30 x 40
FL 30 x 30
FL 20 x 30
FL 20 x 20
1 2 3 5 74 6 8 9 10 20
Flow m3/h (x1000)
30 40 50 60 70 80 90 100 200
2 - 2,8 m/s
VELOCITY DISTRUBITION
2,8 - 4 m/s
2. Flexline Steel Frame Air Handling Units
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3. Frame Drill Technology
The Frame Drill technology developed by the LG R&D team and patented by LG
has been our new milestone toward the sustainable development of our quality
and the increase of our competitive power.
Developed in 2007 as the culmination of almost 2 years of study, the Frame Drill
technology is a new production method. In the Frame Drill business model, the
precision of assembly in air handling unit assembly increases, air handling units
are assembled from standardized parts, units and can be easily assembled in our
outside the factory.
Advantages of the Frame Drill Technology
Modularity
Quality Standardization
Convenience of Transport
Quick Delivery
Can be assembled on site
With the Frame Drill technology, the main body of the air handling unit can be
manufactured in advance with zero tolerance, stocked and thus delivered in a very
short period of time.
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3. Frame Drill Technology
60 mm Profile Assembly
Bottom Panel Assembly
30 mm Profile Assembly
Base Frame and Bottom Panel
Base Frame Assembly
3.1. Assembly StepsWith the Frame Drill Technology, air handling unit assembly can be made quite simply and quickly with a systematic coding logic and pictorial installation manual. The traceable coding logic allows the installer to easily find and implement where each part will be used during assembly.
3.1.1. Base Assembly
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3.1.2. Frame Assembly
3.1.3. Panel Assembly
Assembly of Bottom and Top Groups Assembly of Section Connecting Components
Assembly of Side and Top Panels Finished Section
3. Frame Drill Technology
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4. AHU Performance Standards
4.1.2. Casing Air Leakage
Air leakage tests are performed in the following manner depending on the construction and operating conditions of the air handling unit:
AHUs with sections operating under negative pressure, shall be tested at 400 Pa negative pressure
Units operating under both negative and positive pressure shall be tested with 700 Pa positive pressure
In cases of higher operating pressure than +700 Pa, test shall be performed under operating pressure
Casing Strength EN 1886
Strength Class Maximum Relative Deflection mm/m-1
D1* 4
D2 10
D3 Not required
-400 Pa Casing Air Leakage EN 1886
Air Leakage Class Maximum Leakage Rate (f400) L x s-1 x m- 2
L1 0,15
L2 ** 1,44
L3 3,96
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* The Flexline Steel Frame Air Handling Unit conforms to class D1 with respect to the EN 1886 casing strength test.
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** The Flexline Steel Frame Air Handling Unit conforms to class L2 with respect to the EN 1886 casing air leakage test.
Air handling units can be considered under the three main headings of Mechanical Performance Component Selection Performance Characteristics Engineering Infrastructure and SoftwareAs long as these three major considerations are carried out properly, an optimum product with high performance and minimised energy consumption, capable of correctly meeting customers needs will be manufactured. Two European standards assess performance under these three major headings in air handling units. The first is EN 1886 which evaluates Mechanical Performace and the second is EN 13053 which evaluates Component Selection and Performance Characteristics as well as engineering infrastructure and software.
4.1. EN 1886This standard comprises test requirements and classifications for air handling units which blow and/or extract via a network of air ducts for the purposes of ventilating and/or air conditioning an entire or part of a building.
The standard which evaluates air handling units in terms of Mechanical Performance measures the performance of the Casing Design of the air handling unit by performing 6 separate tests under the headings of Mechanical Strength of Casing, Casing Air Leakage, Filter Bypass Leakage, Thermal Transmittance Coefficient, Thermal Bridging Factor, Acoustic Insulation of Casing.
4.1.1. Mechanical Strength of Casing
There are two basic criteria for mechanical strength;
The deflection in the design conditions of the frame (mm/m) Mechanical strength at maximum operating fan pressure
The test for mechanical strength of casing evaluates the existence of permanent deformation in the casing.
Relative Deflection Test conducted at -1000 Pa pressure and under vacuum (prEN 1886) Maximum Fan Pressure Test conducted at -2500 Pa pressure and under vacuum (prEN 1886)
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4. AHU Performance Standards
4.1.3. Filter Bypass Leakage
Filter Bypass Leakage is related to the amount of filtered air passing through the filter section. It can be defined as the ratio of unfiltered air to the total amount of air.
Filter Bypass Leakage tests are conducted under a pressure differential of 400 Pa in the filter section. The following table shows admissible leakage rates (%k).
Admissible leakage rates are determined with respect to the class of filter used in the section being tested.
4.1.4. Thermal Transmittance
This test procedure enables the classification of the thermal transmittance of the casing of an air handling unit manufactured with standard properties, by using the applied test methods. Thermal transmittance U (W.m-2 K-1) is determined when the stable differential operating temperature is 20 K. The unit should be adjusted to circulate the ambient air 100-110 times, and air velocity on the exterior surface of the section should be below 0.1 m/s.
Thermal transmittance coefficient is classified with to the following values according to the EN 1886 standard.
4.1.5. Thermal Bridging Factor
The possibility of condensation on the unit casing can be estimated with the thermal transmittance coefficient of the casing. However, even when the thermal transmittance coefficient indicates that condensation will not occur on the unit surface, if temperature distribution on the surface is not homogeneous, surface temperature at areas of weak thermal insulation can fall below dew point temperature, which will cause condensation. This case demonstrates that the thermal transmittance coefficient alone is not sufficient to estimate whether condensation will occur on the unit surface.
The thermal bridging value is determined using the same setup as in measuring the thermal transmittance value.
The highest temperature on the units exterior surface when heat transfer is stable (tmax)
Interior temperature under stable conditions (ti) Ambient temperature under stable conditions (ta)
The thermal bridging factor Kb is calculated using the following equation:kb = (ti - tmax) / (ti - ta)
Maximum admissible filter bypass leakage rate as per EN 1886
Air Handling Unit Filter Class G1-G5 F6 F7 F8 F9**
Bypass Leakage Factor (%k) 6 4 2 1 0,5
Thermal Transmittance (U) EN 1886
Class Thermal Transmittance W.m-2 K-1
T1 U 0,5
T2*** 0,5 < U 1,0
T3 1,0 < U 1,4
T4 1,4 < U 2,0
T5 Not required
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*** The Flexline Steel Frame Air Handling Unit conforms to class T2 with respect to the EN 1886 thermal transmittance coefficient test.
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** The Flexline Steel Frame Air Handling Unit conforms to class F9 with respect to the EN 1886 filter bypass leakage test.
700 Pa Casing Air Leakage EN 1886
Air Leakage Class Maximum Leakage Rate (f700) L x s-1 x m- 2
L1 0,22
L2* 0,63
L3 1,9i
* The Flexline Steel Frame Air Handling Unit conforms to class L2 with respect to the EN 1886 casing air leakage test.
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4. AHU Performance Standards
4.1.6. Acoustic Insulation of Casing
The acoustic insulation performance of the casing (casing sound attenuation) is calculated according to ISO 11546-2 and reported for octave bands 125 Hz to 8000 Hz.
4.2. EN 13053This standard comprises test requirements for the performance and rating of air handling units as well as the test requirements and classification of certain equipment and sections in air handling units.
EN 13503 tests examine Correct Component Selection and Characteristics and Engineering Infrastructure and Software Characteristics. The Flexline Air Handling Unit has been certified by comparing the results of tests carried on Real Unit selected by Eurovent officials from the production line to the results obtained from Airware Web, LGs original software. These tests apply to all Flexline Steel Frame Air Handling Units as well as with Heat Recovery.
The factors evaluated as per the EN 13053 standard are the following.
Casing, Fan Section, Coils, Heat Recovery Section, Damper Section, Mixing Section, Humidification, Filter Section, Silencer Section, Accessibility, Surface Smoothness, Inspection Glass and Lights, Measures Against Drainage/Condensation, Air Leakage Test.
Octave Band (Hz) Insulation (dB)
125 21
250 25
500 29
1000 30
2000 32
4000 35
8000 39
Thermal Bridging Factor (kb) EN 1886
Class Thermal Bridging Factor (kb)
TB1 0.75 < kb < 1
TB2* 0.6 kb < 0.75
TB3 0.45 kb < 0.6
TB4 0.3 kb < 0.45
TB5 Not required
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* The Flexline Steel Frame Air Handling Unit conforms to class TB2 with respect to the EN 1886 thermal bridging factor test.
As the thermal bridging value approaches 1, the probability of condensation on unit surfaces decreases and as the value approaches 0, the risk increases. Since the problem of condensation on unit surfaces is very common in practical conditions, the thermal bridging factor should definitely be taken into consideration among other factors when selecting an air handling unit. Exterior and interior surface temperatures of an ideal casing should be homogeneous and close to the ambient temperature to which it is exposed. For this purpose, in order to approach a thermally ideal casing, LG R&D Team have developed the Flexline air handling units that offer no thermal bridging.
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5. Components of AHU
Air
foil
Fan
s
EFFICIENCY AREA OF APPLICATION
Most eff icient of the centrifugal fans General ventilation/air conditioning
Most eff icient operating conditions are achieved with maximum flow of 40-50%
Mainly large systems
Power is also peaked at the maximum eff iciency level
Signif icant energy savings in large industrial fresh air systems
Bac
kw
ard
C
urv
ed
Fan
s
Efficiency is slightly lower General ventilation/air conditioning
Similar eff iciency with Airfoil fan Certain industrial applications where airfoil fans might be exposed to corrosion and wear
Rad
ial F
ans
Higher pressure characteristics than airfoil and backward curved fans
High pressure industrial applications (material handling in industry)
Fan should not be operated when the curve is on the left side of maximum pressure
Easily repaired wheel, which sometimes is coated with a special material
Power constantly increases. This should be considered in motor selection
Not suitable for ventilation/air conditioning
Fo
rwar
d C
urv
ed
Fan
s Fan should not be operated on the right side of maximum pressure
Mainly for low pressure ventilation/air conditioning applications
Most eff icient operating conditions are achieved with maximum flow of 50-60%
Lower maximum efficiency than the other centrifugal fans
5.1. Fans The air handling unit includes a fan section for the purpose of facilitating air circulation, depending on the requirements of the environment. While forward curved fans are preferred for units within the low pressure range, forward curved or backward curved fans can both be used for units within the medium and high pressure ranges. Airfoil fans are commonly preferred due to their efficiency and low noise level operation. Depending on design conditions Plug (without scroll case, single inlet, direct coupled) fans can also be used. Since plug fan systems are directly coupled to the motor shaft, they do not require an additional system for transmission of force. Thus, friction losses resulting from this transmission are minimised, and more efficient systems can be achieved. It is also an advantageous form of application due to the convenience of service and operation.
Fans used in LG Air Handling Units are manufactured from galvanized steel sheets and can be oven painted as an option. Fans are dynamically and statically balanced according to the ISO 1940-G6.3 norm. Flexible connection is used between the fan and the unit body to dampen vibrations. The transmission of the vibration to the casing is prevented by the use of rubber isolators. Spring vibration isolators can also be used upon demand. Flexible connections which may be used from the outside for connecting to the ductwork are also available as an option. If another section is directly coupled to the exhaust side of the fan section, a diffuser is used to enable homogeneous distribution of air over the section and to glean maximum efficiency from the section.
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5. Components of AHU
5.1.1. Fan Laws
To be used in fan selection, manufacturing firms provide fan characteristics curves indicating the variation of fan pressure, efficiency and power with fan air flow for specific types, size and rotation speed (rpm) of fan.
Equations providing the relationships between characteristic variables for dynamically similar fans, are called fan laws.
These variables are: D for fan diameter; n for rotation speed; d for gas density; Q for gas flow; Pt for total fan pressure; Ps for fan static pressure, N for fan power and for fan efficiency.
1. The 1st law indicates the effects of fan diameter speed and gas density on flow rate, pressure and power.
2. The 2nd law indicates the effects of fan diameter, pressure and gas density on flow rate, speed and power.
3. And the 3rd law indicates the effects of fan diameter, flow rate and gas density on speed, pressure and power.
Q : Flow Rate (m3/h) P : Pressure (Pa) d : Gas Density (kg/m3), N : Fan Speed (d/d) D : Fan Diameter (mm) W : Fan Shaft Power (kW)
10,000 m3/h air flow and 600 Pa static pressure
Sample Application: An example of a fan working at 10.000 m3/h air flow and 600 Pa static pressure, indicating the operating characteristics of 10,000 m3/h air flow and 730 Pa static pressure.
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(*) Speed deviations within 4% may be possible with the final selection of the belt drive which may slightly modify technical data
Conclusion:
Theoretical calculation: While 2,27 kW of power is required for the fan shaft at 10.000 m3/h air flow and 600 Pa static pressure; 3,04 kW of power is required for the fan shaft at 10.000 m3/h air flow and 730 Pa static pressure.
Manufacturer selection program: While 2,27 kW of power is required for the fan shaft at 10.000 m3/h air flow and 600 Pa static pressure; 2,74 kW of power is required for the fan shaft at 10.000 m3/h air flow and 730 Pa static pressure.
10,000 m3/h air flow and 730 Pa static pressure
Condition 1 Condition 2
Total Eff iciency % 79,00 % 79,00
Static Eff iciency % 73,00 % 74,00
Static Pressure 600 Pa 730 Pa
Dynamic Pressure 49 Pa 49 Pa
Total Pressure 649 Pa 779 Pa
Fan Power 2,27 kW 2,74 kW
Motor Power 2,93 kW 3,45 kW
Air Flow Rate 10.000 m3/h 10.000 m3/h
Air Velocity 9 m/s 9 m/s
Fan Speed 1292 rpm 1394 rpm
Air Temperature 20,5 C 20,5 C
Motor Eff iciency % 85 % 85
Specif ic Fan Power 1,054 kW/(m3/s) 1,243 kW/(m3/s)
5. Components of AHU
18
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5.1.2. Plug Fan Section
Function: Plug fans are backward curved blade fans without housing that are directly coupled to the motor shaft, that allow precise rpm control. Due to their nature, they create positive pressure in sections where they are located. Various alternatives within the same cross section can be selected according to the required flow rate and pressure values, using the Airweb Air Handling Unit Selection Program.
Structure: Plug fans are positioned on a single unified base. In section positioning, the intake and exhaust clearances required for efficient operation of the fan should be allowed as standard. There are 2 standard doors for accessing intake and exhaust clearances. Rubber based vibration isolators are used as a standard between the motor base and casing to dampen vibrations that may occur. Spring isolators can also be used as an option. A fixed base is used as a standard under the fan base and motor base, to achieve homogeneous transmission of vibration loads to the floor.
Motor: F class insulation, 380 V 50 Hz 3 phase, totally enclosed, fan cooled motors (TEFC) and equipped with short circuit rotor are used as a standard. The motor can be cooled more easily thanks to its aluminum frame. IE2 efficiency class motor is used as standard. A frequency inverter must be used in plug fan systems for rpm control. EC motor applications are optional.
Multiple Fan Application: Double fan application can be provided if needed. In this application, fans are sized to supply half of the total air flow required at the same total static pressure value. A separate frequency inverter is used for each motor.
Operating Conditions: The standard design is suited for operation at -20 C / +40 C while the special design is suited for operation at -20 C / +80 C.
Easy Maintenance: Section designs are made with the minimum service clearances required. Each section has a service door as standard equipment. As an option, a rail conveyance system can be applied, which allows easy removal of the motor and fan outside the section.
Balance Control: All fans are dynamically and statically balanced according to the ISO 1940-G6.3 norm
Vibration Control: Rubber based isolators are used as standard equipment in all fan sections, to dampen vibrations. Spring isolators can also be used as an option. Vibration measurement checks are done on all fan sections as a standard. Flexible vibration dampening connecting elements are used as standard equipment in points where the fan intake nozzle connects to the section.
Positive Pressure Door Application: Positive or negative pressure occurs within the air handling unit, depending on the position of the fan. Since in scroll casing fans, blowing occurs at the fan section outlet, positive pressure occurs in all sections coming after the fan section. And fans without scroll casing, blowing occurs inside the fan section, positive pressure occurs in the fan section and all sections coming after the fan section.
5. Components of AHU
19
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In sections where positive pressure occurs, the service door is built to open inwards and the door is positioned to sit on the aluminum frame on the outside to prevent air leaks. Liquid sealing is applied on the front connections of door locks and sealing elements are found below the precision screw. Thus the conditioned air leaking is prevented from the lock system. The effect of positive pressure minimises the possibility of air leakage.
Furthermore, the guide lever can be easily removed without removing the lock and upon demand, an additional lever can be mounted to allow service doors to open from within the air handling unit.
PLUG FAN
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 1224 1224 1377 1377 1377 1377 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142
5.1.3. Centrifugal Fan Section
Function: Centrifugal fans can be forward curved and backward curved blades and backward. A belt and pulley system is used as a power transmission element. Due to their nature, they create negative pressure in sections where they are located. Various alternatives within the same cross section can be selected according to the required flow rate and pressure values, using the Airweb Air Handling Unit Selection Program.
Structure: Centrifugal fans are positioned on a single unified base. The sections where they are located are sized so that the intake and exhaust clearances required for efficient operation of the fan are provided. Each section has a service door as standard. A specially designed motor tensioning apparatus for adjusting belt tension is provided as standard. Belt and pulley guard and fan protection door which are important safety features are offered optionally. Rubber based vibration isolator are used as a standard between the unified base and casing to dampen vibrations that may occur. Spring isolators can also be used as an option. A fixed base is used as a standard with the fan base and motor base, to achieve homogeneous transmission of vibration loads to the floor.
5. Components of AHU
20
-
Motor: F class insulation, 380 V 50 Hz 3 phase, totally enclosed, fan cooled motors (TEFC) and equipped with short circuit rotor are used as a standard. The motor can be cooled more easily thanks to its aluminum frame. IE2 efficiency class motor is used as standard.
Multiple Fan Application: Double fan application can be provided if needed. In this application, fans are sized to supply half of the total air flow required at the same total static pressure value.
Operating Conditions: The standard design is suited for operation at -20 C / +80 C while the special design is suited for operation at -20 C / +100 C.
Easy Maintenance: Section designs are made with the minimum service clearances required. Each section has a service door as a standard. As an option, a rail conveyance system can be applied which allows easy removal of the motor and fan outside the section.
Balance Control: All fans are dynamically and statically balanced according to the ISO 1940-G6.3 norm. A specially designed motor tensioning system for adjusting belt tension is provided as standard.
Vibration Control: Rubber based isolators are used as standard equipment in all fan sections, to dampen vibrations. Spring isolators can also be used as an option. Vibration measurement checks are done on all fan sections as a standard. Flexible vibration dampening connecting elements are used as standard equipment in points where the fan exhaust nozzle connects to the section.
CENTRIFUGAL FAN
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 1224 1224 1377 1377 1377 1377 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142 2142
5. Components of AHU
21
-
5.2.2. Number of Rows
While designing in specified coil geometry, care should be taken with the number of rows of the coil, which has an impact on the design efficiency. If the number of rows is increased while other factors remain the same capacity increases, surface area increases, air side pressure drop increases, the demand for water flow and consequently the water speed increases. The opposite happens if the number of rows is reduced.
As a general rule, capacity obtained from unit surface area drops as the number of rows increases, rendering the coil less efficient. So, if a 2 row coil is converted to 4 coils, it does not provide twice the capacity. Thus, the lowest possible number of rows should be used in order to increase efficiency. Fin spacing in coils used in air handling units are usually between 2.1-3.2 mm.
Number of rows is among the most important factors influencing pressure drop. This value should also be taken into consideration for coil selection.
5.2.3. Number of Circuits
This is the required number of intakes for the refrigerant to circulate within the coil at a specific pressure drop and flow range.
If the number of circuits increases while all other factors remain the same, water flow decreases, capacity decreases, water side pressure drop decreases. The opposite happens if the number of circuits is reduced.
5.2.4. Structural Properties of Coil
Coil casings are manufactured from galvanized steel sheet as a standard. A combination of backward curved collars and free support system is used in supporting frame. Thus the supports are prevented from abrasion and cutting the tube during thermal expansion or contraction. Intermediate supports are used for additional strength for long coils. Aluminum, hot dip galvanized steel, stainless steel, and copper material can also be used in casings if desired.
Aluminum, epoxy coated aluminum and copper fins are manufactured with automatic blocks which adjust thefin height and fin spacing. Fin surfaces are plain or corrugated. 1/2 and 5/8 copper tubes are mechanically expanded, providing tight contact with fin collars. This inflation system forges an excellent mechanical connection between the fin and tube in all defined operating conditions, facilitating the utmost level of heat transfer between air and internal refrigerant.
5.2. CoilsCoils are equipments used in air handling units, for the heating or cooling of air. Refrigerant and water systems are offered for heating and cooling applications. Coils are selected by the Airware Air Handling Unit Selection Software from cold water, hot water and direct expansion types, to provide optimum performance conditions. In accordance with system requirements, copper tube-aluminium fin or steel tube-steel fin coils are used in air handling units. Standard tube diameters used are 1/2 and 5/8. In aluminium finned designs, epoxy coating, providing high corrosion resistance for special can be applicable as an option.
5.2.1. Coil Geometry
PropertiesModel
3833-5/8 3228-1/2 4035-5/8
Distance Between Tubes 38,1 mm 31,75 mm 40 mm
Distance Between Rows 33 mm 28 mm 34,64 mm
Tube Diameter 5/8 1/2 5/8
Tube Alignment Staggered Staggered Staggered
5. Components of AHU
22
-
5.2.5. Testing of Coils
Unless otherwise specified, all coils can be tested after assembly, by immersion into a water filled pool under a pressure of 20 kg/cm2. Testing can also be performed under a pressure of 30 kg/cm2 upon demand.
5.2.6. Cooling Coils
Function: Used for cooling air.
Model Types: Two types exist according to the type of refrigerant used for cooling: Water and gas.
Structure: They are manufactured from copper tube aluminum fins as a standard feature. The casing is manufactured from galvanized steel sheet. Can also be manufactured from stainless steel sheet as an option.
Copper Tube: Tube diameters used are 5/8 and 1/2.
Fin Pitch: 5 pitch types can be applied, which are 2.1, 2.5, 2.8, 3 and 3.2 mm. Fins are manufactured from aluminum as standard. Fins can be epoxy coated upon demand
Pipe Connections: Pipe connections vary according to the characteristics of the coil selected. Pipe connections are manufactured to extend outside the air handling unit as a standard feature in water and gas systems. A flanged application is optional in water coils.
Condensation Pan: Applied as a standard feature in all cooling sections. It is manufactured from stainless steel. Being double inclined, it allows very fast drainage of the condensated water. Undersides of condensation pans are insulated with mineral wool. The standard drain pipe diameter is 1. It does not allow accumulation of water and ensures quick drainage.
Droplet Eliminator: Droplet eliminators are applied as a standard feature in all cooling exchangers. Drop eliminators manufactured from polypropylene which is resistant to temperatures of up to 130 C. Their casing is manufactured from stainless steel as a standard feature. Standard rail mechanism allows easy removal and servicing.
Air side pressure drop generation based on the surface speed of drop eliminator
5. Components of AHU
23
-
5.2.7. The Drainage System
The majority of cooling coils have been placed to allow supply air to pass through them onto the units. As a result, they are subjected to negative (-) static pressure. If measures to balance pressure on the condensation drainage line have not been taken, air that is suddenly and quickly sucked back from drainage tubes will cause the condensate to accumulate in the drain pan.
The water which collects as the unit continues to operate will be accumulated with the air current and cause the water filling the drain pan to seep into air intake ducts and/or water flooding damage in the building.
For this reason, traps must be used for pans to avoid water accumulation in air handling units.
Example:Negative Static Pressure = 65 mmWGFor safety = 20 mmSS
5.2.8. Heating CoilsFunction: Used for heating air.
Model Types: Two types exist according to the type of refrigerant used for heating: water and gas.
Structure: They are manufactured from copper tube aluminum fins as a standard feature. The casing is manufactured from galvanized steel sheet. Can also be manufactured from stainless steel sheet as an option.
Copper Tube: Tube diameters used are 5/8 and 1/2.
Pitch: 5 pitch types can be applied, which are 2.1, 2.5, 2.8, 3 and 3.2 mm. Fins are manufactured from aluminum as standard. They can be epoxy coated as an option.
Tubing Connections: Tubing connections vary according to the characteristics of the coil selected. Tubing connections are manufactured to extend outside the air handling unit as a standard feature in water and gas systems. A flanged application is optional in water coils.
COOLING COIL
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765 765
Height H = 85 mmSS Hmin = Static Pressure + 20 mm
5. Components of AHU
24
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5.2.9. Electrical HeaterFunction: Used for heating air.
Model Types: Can be selected with 1-6 rows and 1-3 stages. Higher row numbers are offered as an option.
Structure: Its casing is manufactured from stainless steel as a standard feature. Non-combustible guards are used for all cabling.
Heating Elements: Straight rod or coiled resistances are used.
Protection: An automatic reset temperature sensor is supplied ready to connect power panel as a standard. The safety thermostat with manual reset, pressure differential sensor for detection of air flow and door protection switch are offered as optional features.
HEATING COIL
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 306 306 306 306 306 306 306 306 306 306 306 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459
ELECTRICAL HEATER
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459 459
Freeze Protection: A freeze-free thermostat is supplied as an optional feature for freeze protection
5. Components of AHU
25
-
5.3. Heat Recovery SystemsHeat recovery systems used in air conditioning systems preheat (or precool) the fresh air taken from outdoor conditions using exhaust air, bringing the enthalpy and temperature of fresh air to interior space conditions. However, in these systems, if energy is taken from another system, heat recovery does not occur. According to VDI 2071, the transfer of mass is not heat recovery. Thus, heat recovery can not be achieved by mixing air.
5.3.1. Basic Principle of Heat Recovery
Sensible heat is transfer is made primarily in heat recovery units. Latent heat can be transferred depending on the structure of the heat recovery unit. Heat recovery units can be divided in 2 general categories:
Recuperative Systems Regenerative Systems
Recuperative Systems: It is a method of heat transfer that occurs at the moment of heat expulsion, without the use of an intermediate fluid. Due to the absence of an intermediate fluid, it is more efficient than other systems.
Regenerative Systems: It is the method of heat transfer where the heat is first transferred to the intermediate fluid, and then to the environment that is the recipient of heat. Additional energy is required in some systems to facilitate the circulation of the intermediate fluid.
5.3.2. Rotary Heat Recovery
It is a form of heat recovery operating in the regenerative style. The rotor consists of a circular aluminum mass containing pores to allow the passage of air. Heat recovery is achieved with the turning of the rotor. The heat and temperature of the exhaust air is transferred to the rotor blades with the turning motion of the heat exchanger rotor. The transferred moisture and heat energy is passed on to fresh air by the continued rotation. In addition to heat transfer conducted during the winter, it is also possible to save energy and carry out dehumidification with the same unit in the summer. The heat wheel is usually commanded by speed control. Heat recovery ratio usually varies between 70-85% in rotary heat recovery systems.
Function: It is a form of heat recovery operating in the regenerative style.
Models: 1. Condensation Rotor: It is a heat wheel that is only capable of carrying out the transfer of sensible heat, to be used in standard comfort ventilation applications. It also conducts transfer of humidity if one of the air currents is as cold as the dew point. The fill consists one row of plain and one row of shaped standard aluminum layers.
2. De-Humidifying Rotor: It is suited to standard comfort ventilation applications. It also conducts transfer of humidity if one of the air currents is as cold as the dew point (winter). The fill consists one row of plain and one row of shaped standard aluminum layers. Surfaces have been specially treated, raising their capacity for de-humidification.
3. Enthalpy Rotor: The enthalpy rotor wheel also conducts a high amount of latent heat transfer in addition to (standard) sensible heat recovery. The moisture
5. Components of AHU
26
-
transfer capabilities of these enthalpy transfer wheels which have been coated with adsorptive surfaces have been increased. The capacity is fixed and high throughout the year. The heat wheel fill is manufactured by winding one row of plain and one row of shaped standard aluminum bands. Surfaces have been covered with a special adsorbent, offering superior adsorption.
Easy Maintenance: There is a service door in the side of the motor, for easy servicing of the rotor.
Purge Chamber: In heat wheels, the purge chamber and air is important in two aspects. While the contaminated return air that would otherwise be carried into the air is expelled, the fill which has been contaminated by the return air is also cleaned.
The purge chamber and purged air is the most significant element and concept for heat wheels. It is an effective application, carried out over a chamber developed for preventing the contaminated air carried from the return air to the fresh air. It is based on the principle where the contaminated air that passes to the outdoor air with the heat exchanger filling is purged off the filling and transferred to the exhaust air side.
Speed Control: 1. Constant speed: The gear motor offers constant rpm at the highest rotating speed. These triphase induction motors have F class insulation. They are equipped with lifetime self lubricated endless screw gear box.
2. Variable Speed: It has the function of adjusting the required speed of rotation of the rotor. In this way, heat recovery can be achieved to the desired extent. Variable speed varies control unit input signals between 0-100 Hz and supplies an output frequency.
ROTARY HEAT RECOVERY
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918 918
5. Components of AHU
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5.3.3. Plate Type Heat Recovery
Its a form of heat recovery operating in the regenerative style. The system operates on the counter-flow principle. Fresh air and exhaust air pass through two separate layers. Plates are designed to facilitate maximum heat transfer. A bypass damper can be added to the heat recovery section, to control air flow, enable free-cooling and prevent freezing.
Function: It enables highly efficient heat recovery in the recuperative style.
Application: Plate type heat recovery is used in applications where the mixing of indoor and outdoor air is not desired.
Models: 1. Cross Flow - Heat recovery up to 65%
2. Counter Flow - Heat recovery up to 90%
Free-Cooling Bypass Damper Application: In plate type heat recovery systems, fresh air may need to be transferred to the indoor space without being subjected to heat recovery, in order to take advantage from the energy of outdoor air, particularly in mid season. Thus, we condition the indoor space with the low temperature of the fresh air, without carrying out additional cooling. A bypass damper can be used in plate type heat recovery systems, to facilitate this process.
Section Structure: There is a stainless steel condensation pan on the exhaust side and a stainless steel drainage pipe of this pan is hermetically extended outside the unit. It is important for efficient system operation to mount a filter outside the filter on the intake side and before the heat recovery coil on the exhaust side.
5. Components of AHU
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PLATE TYPE HEAT RECOVERY
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 1224 1224 1224 1224 1224 1224 1683 1683 1683 1683 1989 1989 1989 1989 1989 1989 1989 1989 1989 1989 1989 1989 1989 2295 2295 2295 2295 2295 2601 2601 2601 2601 2601 2601 2601 2601 2601 2601 2601 2601 2601
5.3.4. Runaround Heat Recovery
Function: It is a form of heat recovery operating in the regenerative style.
Application:
Heat is transferred via air passing over two interconnected coils. One of the coils is at the side of outdoor air and the other at the side of exhaust air and these are connected with piping. The fluid facilitating heat transfer circulates within these tubes. Water is usually used as fluid. Antifreeze is added if necessary. The fluid facilitating heat transfer circulates within the system with the aid of a pump. The flow in this system is regulated with valves. If the air exhaust from the system falls below the dew point, condensation occurs. This leads to an additional latent heat transfer. There is risk of frosting in the system. The enclosed circulation system allows the process to occur even when the outdoor air and exhaust air are at long distances to each other. Air flows do not have to come together, but additional energy to facilitate the circuit is needed. This is the electrical power required to operate the pump that facilitates the circuit. The amount of recovered heat can be easily regulated by controlling the flow of water. It can be turned off independent of the air handling unit if necessary.
Condensation Pan: There is a stainless steel condensation pan on the exhaust side and a stainless steel drainage pipe of this pan is hermetically extended outside the unit.
5. Components of AHU
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5.3.5. Heat Pipe Heat Recovery
Function: It is a form of heat recovery operating in the regenerative style.
Application: In this system, refrigerant is used to transfer heat and the unit operates on the principle of the refrigerant vaporizing upon meeting the system return air and rising within the tube and then transferring its heat to cold air and condensing back into liquid. The system can operate in the -30C and 55C temperature range without any problems. The heatpipe can be used horizontally side by side or vertically stacked. Horizontal types can be designed to conduct heat recovery also in summer conditions when required. A drop eliminator is mounted on the exhaust side if indeed.
Condensation Pan: There is a stainless steel condensation pan and the drainage pipe (stainless steel) of this pan is hermetically extended outside the unit. Mounting a filter before the heat recovery coil is recommended to prevent contamination.
5. Components of AHU
30
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5.4. FiltersThe function of filter sections is to prevent the accumulation of dust on the internal surfaces of coils and panels, extending the efficient lifetime of the air handling unit. In addition, the basic purpose in some applications is to purify the unwanted particles at supplied air. Models with permeability ranging between classes G3-F9 are used in air handling units. Depending on the place and purpose of application, they can be classified as pre-filtration, sensitive filtration and absolute filtration. Filter types include panel filters, bag filters, carbon filters and rigid filters.
Panel, bag and carbon filters are manufactured as a standard of high quality galvanized steel while rigid filters have a plastic frame.
Filter Casings: LG uses two types of filter casing depending on the area of application.
Standard Casing: It is designed to hermetically place bag filters, rigid filters and active carbon filters within the system. They are manufactured from galvanized or stainless steel. There are three fastening depths (25 mm, 50 mm, 100 mm). Filters are fastened with the EPDM seal placed between the filter and casing and spring clips which allow the fastening of the seal. Special casing design enables the use of both a panel and bag filter within the same casing.
Quick Assembly Casing: They are designed for purposes similar to standard casings; filters are fastened to the casing with steel reinforced profile seals and connection is made using a special tightening system.
5. Components of AHU
31
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FILTER CLASSIFICATIONS
Particle Size Examples of Particle Filter Class Sample Applications
Panel dust f ilter for particles larger than 10 m
Insects, textile f ibers and hair, sand, f ly ash, pollen, spores, cement dust
G1Simple applications (eg. for insect protection in compact devices)
G2
G3 Preliminary and peripheral air f ilter for civil protection facilities; air outlets for spray paint cabinets and kitchen outlets, etc; contamination protection for air conditioning units and compact devices (e.g. window type air conditioners, fans); pre-filter for F9-F8 class f ilters
G4
G5
Fine dust f ilter for particles 1-10 m
Pollens, cement dust, particles that cause dust precipitation, bacteria and microbes on host particles
F5Outdoor air f ilters for sites that have low demand (e.g. factory sheds, storage facilities, indoor parking lots)
F5Preliminary and peripheral air f iltering in ventilation stations; after f ilter in sales facilities, shopping malls, off ices and certain production facilities; pre-filter for F9 - H11 class f ilters
F6
F7
Oil smoke, tobacco smoke, metal oxide smoke
F7 After f ilters in air conditioning systems for offices, production facilities, control centers, hospitals, data processing centers; pre-filter for H11 - H13 class f ilters
F8
F9
Suspended material f ilter for particles smaller than 1 m
Microbes, bacteria, viruses, tobacco smoke, metal oxide smoke
H10
After f ilter for such environments as laboratories, pharmaceutical production facilities
H11
H12
H11After f ilter for clean rooms of 100000 or 10000 classes
Oil vapor formation, soot and radioactive materials
H12After f ilter for clean rooms of 10000 or 100 classes, outlet air f ilter in core technology facilities H13
Aerosols
H14
After f ilter for clean rooms of 10 or 1 classesH15
H16
Separation of materials that are harmful if inhaled
Kitchen outlet f ilters, hazardous materials suspended in the air, smog, combustion gas, solvent vapor, food smell, stench
Active carbon filterOutlet air f ilters that are bound by the environment protection clauses, all environments that contain hazardous gases
We can classify filters according to their particle permeability as follows.
Final Pressure Drop for Filters According to EN 13053
Filter Class Final Pressure Drop
G1-G4 150 Pa
F5-F7 250 Pa
F8-F9 350 Pa
5. Components of AHU
32
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5.4.1. Panel Filter
Function: Used for pre-filtration and main filtration.
Filter Class: G3-G4 (EN 779).
Filter Material: Synthetic polyester.
Filter Surface Area: Offers a wide surface area due to its pleated form.
Manufactured in G3 and G4 classes, these filters are produced from high quality galvanized steel, PVC or fibreglass material. The decisive point in the design of these filters which have a gravimetric efficiency of 85 - 95%, is creating a corrugated structure and hence a larger filtering surface. Panel filters which can withstand temperatures of up to 180C are used in air handling units for pre-filtration to lengthen the useful life of higher particle efficiency filters. Their being washable is a significant advantage which lowers their operational and maintenance costs and which make them popular.
Shown below is the flow rate-pressure drop chart for the standard dimension filter module.
PANEL FILTER
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40
x 5
0
FL40
x 6
0
FL40
x 7
0
FL50
x 5
0
FL50
x 6
0
FL50
x 7
0
FL50
x 8
0
FL50
x 9
0
FL50
x 1
00
FL60
x 6
0
FL60
x 7
0
FL60
x 8
0
FL60
x 9
0
FL60
x 1
00
FL60
x 1
10
FL60
x 1
20
FL70
x 7
0
FL70
x 8
0
FL70
x 9
0
FL70
x 1
00
FL70
x 1
10
FL80
x 8
0
FL80
x 9
0
FL80
x 1
00
FL80
x 1
10
FL80
x 1
20
FL80
x 1
30
FL90
x 9
0
FL90
x 1
00
FL90
x 1
10
FL90
x 1
20
FL90
x 1
30
FL10
0 x
100
FL10
0 x
110
B 612 612 918 918 918 918 1224 1224 1224 1224 1530 1530 1530 1530 1530 1530 1836 1836 1836 1836 1836 1836 1836 2142 2142 2142 2142 2142 2508 2508 2508 2508 2508 2508 2814 2814 2814 2814 2814 3120 3120
B 772 772 1078 1078 1078 1078 1384 1384 1384 1384 1690 1690 1690 1690 1690 1690 1996 1996 1996 1996 1996 1996 1996 2302 2302 2302 2302 2302 2668 2668 2668 2668 2668 2668 2974 2974 2974 2974 2974 3280 3280
H 612 918 918 1224 1530 1836 1224 1530 1836 2142 1530 1836 2142 2508 2814 3120 1836 2142 2508 2814 3120 3426 3732 2142 2508 2814 3120 3426 2508 2814 3120 3426 3732 4038 2814 3120 3426 3732 4038 3120 3426
H 722 1028 1028 1334 1640 1946 1334 1640 1946 2252 1640 1946 2252 2618 2924 3230 1946 2252 2618 2924 3230 3536 3842 2252 2618 2924 3230 3536 2618 2924 3230 3536 3842 4148 2924 3230 3536 3842 4148 3230 3536
L 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612 612
5. Components of AHU
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5.4.2. Bag Filter
Function: Used for main filtration
Filter Class: F5-F6-F7-F8-F9 (EN 779).
Filter Material: Syntetic fiber.
Filter Surface Area: Offers a wide surface area due to its bag form.
Length of Filter Bags: 600 mm - 300 mm.
Filter Frame Thickness: 25 mm (standard).
Insulation: Filters are fastened to the casing with reinforced, cellular, profile seals (F9 leakage class according to EN 1886).
Filter Casing: Standard casing and quick assembly casing can be used in bag filters.
Placement of F9 Filter: The F9 class filter must always be placed in the positive pressure side.
Manufactured in various classes from F5 to F9, bag filters are produced with galvanized frames as a standard. The filtering element is produced from synthetic fibre material. Its extended surface design leads to low flow rates, thus facilitating low pressure loss, high dust capturing capacity, long use and low energy costs.
Shown below is the flow rate-pressure drop chart for the standard dimension filter module.
BAG FILTER
Size
FL20
x 2
0
FL20
x 3
0
FL30
x 3
0
FL30
x 4
0
FL30
x 5
0
FL30
x 6
0
FL40
x 4
0
FL40