AHU (air handling unit)

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AHU (air handling unit) covers vertical (air volume from 2000 ~ 60000m3 /h), horizontal (wind increased from 2000 ~ 60000m3/h), and ceiling-type (air volume from 1000 ~ 16000m3/h) three series of air-handling unit to meet customers’ need of cooling, heating, humidification, dehumidification and so on. It is widely applied in hotels, theaters, shopping malls, office buildings and a variety of places requires comfortable environment. It also can be used in electronics, chemical, medical, pharmaceutical, cigarettes, food, light engineering and other industrial buildings.

Our AHU is under installarion in North America

AHU (air handling unit) (5)

AHU (air handling unit) (5)

The characteristics of air-handling units

Frame structure: aluminum framework structure is adopted, which is made of high-strength aluminum alloy. Each corner of the framework is made of special castings, allowing the section bar to plug into it. This structure has the following features:

A: good performance in mechanical strength, light in weight, corrosion resistance, beautiful shape and accurate size.

B: flexible assemblage, very convenient to install, remove and maintenance. Also, it has longer service life than steel structure.

Panel structure: A: the panel is formed by two layers of colored steel plates. Filler between the layers is high-density polyurethane or polystyrene, which has a better performance in thermal isolation than other materials like glass wool. No thermal bridge will be produced while working in all weather or working conditions.

B: panels are fixed in a special way, with sealing material to strengthen its thermal and air resistance. This structure has the best performance in thermal isolation, noise reduction and intensity, so it can be used in places require high quality of air.

Fan, electrical motor: A: unit adopts centrifugal fan with both air inlet. The fan runs smoothly in the rigorous static and dynamic balance test.

B: With ball bearings sealed, and functions of pre-lubricating, self-aligning, self-locking, automatic thrust, etc., the fan is maintenance-free in normal use.

C: fans of a small model unit are driven directly by external sub-motor, no belt, and easy to maintain.

Filter: unit filter is coarse plate. Filter material is cleanable convex Nylon net.

Cooler: the selected parameters of surface air cooler are designed by CAD/coi1 software. A standard cooler normally has copper pipes of φ6. It is tightened by an overall rise up of brass strung by corrugated aluminum fin tubes. Staggered copper pipes have good heat transfer performance, low airflow resistance and superior corrosion resistance, ensuring the cooler has a higher heat transfer coefficient and a longer life.

 

Note: 1. method to decide units type: facing the air inlet (i.e., along with air-flow direction), if the inlet and outlet tube is on the left, it is left form, if on the right, it is right form.

2. According to client’s specific need, our company can configure additional electrical protection devices and air quantity speed regulation (including variable frequency controller and thyristor controller).

3. Structures corresponding with the external air duct: as shown below, A is the default choice.

Air handling unit performance (Table I ~ Table VI)

1. Air-conditioning working condition means that the dry bulb temperature of intake air is 27℃, wet bulb 19.5℃ while cooling, and dry bulb 21℃ while heating.

2. Fresh air working conditions (l00% fresh air) means when cooling, dry bulb temperature of intake air is 350℃, wet bulb temperature 28℃, dry bulb temperature of intake air -5℃ while heating.

3. Cold water temperature: supply water is 7℃, back water is 12℃. Hot water supply temperature is 60℃.

4. The motor power values from table I to tableVI correspond with its different residual pressure. The residual pressure is flexible, which can be decided by our customers according to needs.

5. The noise values from table I to table VI are tested in the muffling section 1m (GB/T9068) away from each surface of the units.

6. Cooling capacity ratioαchanges with the refrigerants temperature ( i.e. tw) as follows.

7. Cooling capacity ratio αchanges with the wet bulb temperature of intake air( i.e. ts) as follows.

Air-handling unit installation instructions
● In units neighboring, especially the side with maintenance door and external water pipe, enough space should be reserved for filter extraction and maintenance.
● A horizontal base is indispensable. Any slant base will affect normal water drainage of water pond and working fan’s dynamic balance.
● Air is sucked in by unit. The heating hot water temperature must not be higher than 65℃. The water must be cleaned (soft water). A water filter is needed if necessary.
● The condensate pipe of units must be equipped with steam trap. The height of it can be measured through residual pressure + height of 100nn water (following picture is the specific requirement), and a smooth condensate pipe and drainage slope be higher than 0.005 must be assured.
● Weight of air pipes and water pipes connected to the units must be born by a hanger or support column not the unit itself.
● The electric motor power supply must have protection when the power lacks phase or is overloaded. Voltage reduction should be started in a motor with power more than 11Kw. Units power supply is 380V, 50Hz.
● After the installation, before switching on the power, please rotate the leaves of fan with hand to check if they are in good condition. Don’t forget to check the voltage to see if it is the right one, without missing phase or is an imbalance triphase. After power on, first of all, switch on the electric power to check if the fan rotates in the right direction, if not, please change the phase sequence. Only without exceptions can the unit be put to use. No empty running for the unit.
● Before the unit starts, air inlet and outlet valve should be half open. After the start, please adjust the opening space of air valve to make sure that the motor runs within rated current.
● Air filter should be cleaned regularly. During non-use period in winter, measures of freezing-proof are necessary, or empty the coil to prevent it from frost cracking.
● After two years of operation, a comprehensive maintenance is necessary for the unit, including cleaning dirt on heat exchanger fins and scale in water pipes.
● A professional technician is needed if the unit breaks down.
Ordering Guide
◆ Please be sure of the size, model, cool and heat quantity and left/right form in selecting air handling unit.
◆ Electrical controller is not part of the unit. However, the electric protector and air quantity speed regulation (including variable frequency controller and thyristor controller) is addable according to clients’ needs. Neither is inlet and outlet air quantity valve part of the unit. Please inform us before ordering if you need it.
◆ Our products are not limited to our routine units. According to clients’ special needs, unit can be equipped with additional electrical (auxiliary) heater, humidifier (steam humidifier, wet membrane humidifier, high-pressure spray humidifier and electrode humidifier), silencerand so on.
Our company follows the principle of constantly improving our products. Please kindly excuse us if we do not inform you in time about changes or improvement of product performance, specifications, and materials, and keep in touch with us to obtain the latest information.

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