GRAD combined air handling unit is developed on the basis of our decades of experience in the air conditioning unit production. We introduced advanced technologies and production techniques and followed the European standard, EN1886-1997.

The shell of the combined air handling unit is made of two-layer color steel plate which is filled with polyurethane foam or polystyrene. The frame is made of special steel or aluminum alloy. The sealing performance between shell and frame is great, so limited air could leak from the seam. Copper pipe coved by aluminum corrugated fin is adopted for the heat exchanger, making the heat transfer coefficient very high.

As an air conditioner component, our combined air handling unit can be divided into several sections: blowing-in section, heat exchanging section, humidifying section, steam heating section, middle efficiency filtering section, mixing section, energy recovery section, and air returning section. Besides, the structure could be customized according to clients' requirements.

Feature of different sections
Mixing section
In this section, the return air will be mixed with fresh air. Unless specified, this section comes with an access door, but the air flow valve is not included.

Air flow control section
The air flow control section of the combined air handling unit can adjust the air flow of the air conditioning system. Actually, it is the combination of the air extraction section and air returning section (or fresh air section). If there is no specific statement, this section does not include air flow valves for all of these sub-sections. However, there is an air flow control valve for the entire air flow control section, and an access door is available for this section.

Energy recovery section
A certain amount of energy of the exhaust will be transferred to fresh air in the energy recovery section. The recovery rate could be higher than 70%. Thus the power consumption is greatly reduced.

Heat exchanging and water retaining section
The temperature and humidity of the air will be reduced in this section. To heat the temperature, you can use warm water below 65℃. The water tray and condensed water outlet pipe are available at the bottom of this unit. A water retaining board is needed when the face velocity is above 2.5m/s.

Steam Heating Section
This section has a composite structure of steel and aluminum, featuring high heating efficiency, high internal pressure, corrosion resistance and bacteria free.

Steam Humidifying Section
Humidify the air with steam humidifier

Filtration Section
Various kinds of filters are available for you to choose, G3 for primary filtration, F6 for intermediate filtration.

Air Output Section
Equipped with a high-efficiency centrifugal fan and a built-in damper, the air output section has a stable performance. The output air mainly comes from a horizontal and vertical direction.

Application
For modular AC units of ZK series, there are various working sections, including air output section, fan coil cooling section, heating section, humidifying section and filtration section. You are welcome to choose and combine those functional sections in consideration of your special requirements and total budget. Because of the multiple choice and combination, our ZK series is exactly an ideal AC for restaurants, office buildings, hospitals, theaters and shopping mall. It also finds a huge market in such industries as electromechanical, electronic, textile, pharmaceutical, chemical, energy and food.

Advantage
This combined air handling unit comes with reasonable structure, elegant appearance, and multi-functions. Its various sections can be freely combined, and the operation is quite stable. It is also quite convenient to install and maintain the machine. There are two prominent advantages that we'd like to point out. The first one is the special sterilization device which can keep the air in the room clean. The second one is the energy recovery device that can reduce the operating cost and power consumption.

Technical Parameters of the Combined Air Handling Unit
Working condition of return air: Dry bulb temperature of inlet air is 27℃, wet bulb temperature 19.5℃; temperature of input water is 7℃, temperature of output water 12℃.

Working condition of fresh air: Dry bulb temperature of inlet air is 35℃, while wet bulb temperature 28℃. Temperature of input water is 7℃, while temperature of output water is 12℃.