1 - CASING
ALDAĞ AKS Air Handling Units are EUROVENT (AKS-600 AKS-2535) certified and tested in accordance with DIN 1946 /4: 2008, DIN EN ISO 5167 Standard.
• Maximum deflection for mechanical strength of the casing is compatible with EN 1886 Standard. The positive and negative pressure is compatible with Dl (M) Class. Maximum Leakage between -400 Pa and +700 Pa is compatible with L1 Class.
Filter By-Pass Leakage is compatible with F9 Class. There exist two different models of casing for AHU, certified by Eurovent so thermal conductivity resistance is compatible with T2 &T3 Class.
Thermal Bridge is compatible with TB1&TB2 Class.
• The panels and service doors are double skinned &made of submersion galvanized steel sheets. The outer skin steel sheets are RAL 9002 polyester powder coated. The steel thickness is minimum 0,9 mm for outer skin sheets and 0,8mm for inner skin sheets.
• AII the interior surfaces of the casing are suitable for washing and cleaning and completely smooth without any welding at the joints.
• 50 mm. rock wool insulation is used between the inner and the outer steel sheets of the panels.
• The panels can be easily mounted and dismounted externally.
• The air handling unit sections are connected externally by mechanical fasteners.
• On the casing of the air handling units, there exists labels which include the technical specifications of the unit. in addition, on each section casing, there is an identification label which is long lasting and resistant to humidity and water.
• In case air handling unit sections are partially delivered to the installation place, in order to provide easy and accurate onsite assembly, another identification label is placed on each section which includes the information of section name and section number.
2 - SUPPLY FAN - EXHAUST FAN SECTION
AHUs are equipped with double inlet forward curved or double inlet backward curved energy efficient centrifugal fans and plug fans. As an option, EC plug fans can be equipped. The supply fans and exhaust fans are dynamically and statically balanced and made of galvanized steel.
The fan type is selected according to the air flow, pressure and efficiency curves. The centrifugal fans and plug fans are selected within energy efficiency range 60% and 80%. The fan base is specially determined to increase the lifetime of the fan bearing. In case the total pressure is over 1000 Pascal, it is recommended to use double inlet backward curved fans. The fan speed is selected compatible with the motor speed. The fan - motor group is fastened on the base so as to enable belt tensioning arrangement. The fan - motor group is fastened to the main casing with the rubber vibration elements which prevent vibration problems. The belt - pulley system transmits the power from motor to the fan.
The fan bearings are easily removed and replaced. The electric motors are IP55, IE2-IE3-IE4, 380 Volt 50 Hz. The electric motor power is selected to be 15% or 20% more than fan shaft power to be on the safe side. The fan outlet is connected with a flexible to the section frame so that no vibration is transmitted to the casing or duct. The position of fan inlet and fan outlet can be changed upon request. The plug fans are direct driven by the motor. Depending on the pressure, the desired fan speed can be arranged by motor drivers.
3 - MIXING BOX SECTION
Mixing Box Section consists of 3 dampers and a cassette filter between G2 - G4 filtration class. According to the project specifications, some of the indoor air is exhausted through the exhaust damper on this section and same amount of fresh air is supplied through the fresh air damper. The fresh air is mixed with the indoor air and the conditioned air is supplied. The amounts of the indoor air and fresh air to be mixed can be arranged at the desired ratio using damper motors.
The dampers have aluminum aerodynamic blades. Damper blades are equipped with plastic seals to assure tightness. The G4 filter is placed in galvanized steel frames. The filter is protected on both sides by perforated steel sheets. The filter frames, sliding on the rails, can easily be removed and cleaned.
4 - BAG FILTER SECTION
Bag filters are classified as F5- F9 according to the dust holding capacities. F5-F9 filters with the efficiency from 90% up to 99% are used in the bag filter section. The filters are easily removable from the frames. The filters cover the whole cross-sectional area of the filter section.
5 - HEAT RECOVERY SECTION
If there is a need for 100% fresh air at the project specifications, plate type or rotary type heat recovery option can be used. The sorption rotor in the air handling unit substantially reduces the need for humidification in winter conditions and dehumidification in summer conditions by sensible and latent heat transfer. Thus, it provides significant saving in energy consumption during all four seasons. The efficiency ratio is between 70% and 85%. Special heat recovery section applications can also be applied using rotary heat exchangers which makes only sensible heat transfer.
6 - HEATING - COOLING SECTION
The heating coil and cooling coil is determined according to the type of the fluid used in the system. The heating - cooling section can be equipped with cold-hot-overheated water coil, steam coil, direct expansion (DX) coil or electrical heater. The coils are copper tube aluminum finned. The aluminum fins are fastened on the copper tubes by mechanical expansion method. Thus, maximum thermal efficiency is achieved. The cross-sectional area of the section is determined according to the air velocity over the coil.
The average air velocity on the coil should be around 2,5-3 m/s. For the cooling coils, the condensed water is collected and discharged through the stainless-steel epoxy coated and insulated drain pan. If the air velocity is over 3 m/s, the heating-cooling section is also equipped with aluminum or PVC drop eliminators.
7 - HUMIDIFIER SECTION
lf humidification of supply air is requested, air handling units can also be equipped with a humidifier section as an option. There are two types of humidifying method. The air passing through the AHU is humidified flowing through the pulverized water. There is a leak proof water pool under the section. Water is pumped to the injectors with high pressure for pulverization. The humidifier section is equipped with aluminum air diffusers at the air intake which enable uniform air distribution. PVC eliminators are placed at the section outlet to prevent water drifting. Optionally, for hygienic applications if steam humidifier is requested, the humidifier section is equipped with a steam generator.
8 - SOUND ATTENUATOR SECTION
lf requested, the air handling unit can also be equipped with sound attenuator after the supply fan sectionand / orbefore the exhaust fan section. The sound attenuator section consists of sound absorbing baffles. The sound absorbing baffles are made of galvanized steel panels with rock wool and perforated steel sheets. The size of the baffles is determined depending on the sound absorption coefficients.