Rooftop DX Type Air Handling Units AHU

The wire controller is simple and convenient, flexible in application, and widely used in small and medium-sized office-level business spaces.  

Building systems based on the MODBUS protocol can be directly connected to the centralized control system through the MODBUS communication interface standard on the unit, no need to access conversion equipment, and are suitable for large and medium sized air-conditioning locations.

Dual Temperature Sensors
Innovative design with two temperature sensors, one at return vent, and one at the control panel, to detect the indoor temperature around the room, and make sure the hot wind(winter heating mode) would be sent to each corner of the room uniformly.

As the core element of the refrigeration system, the heat exchanger directly determines whether the air conditioning system is reliable and energy-saving.
Holtop combined with many years of outdoor unit development experience and market demand, developed a new generation of U-shaped heat exchanger. Such advanced and efficient heat exchangers have made Holtop's HFM series highly efficient and energy-saving, and also meeting the Holtop Vision of "making air treatment more healthy and energy-saving".
The airflow of the fan is effectively used, and the heat exchange area is fully expanded without increasing the space of the unit, and the heat exchange efficiency is greatly improved.
Compact structure, high strength, more convenient for installation and maintenance.
The use of hydrophilic membrane aluminum fins improves the heat transfer wet film heat transfer coefficient and provides the overall heat transfer coefficient of the unit.

The copper tube adopts φ7.94 thread copper tube, the flow rate is moderate, and the comprehensive performance of heat exchange defrosting is optimal.
The distance between φ7 copper tubes is the smallest, the frost has a great influence on the heat transfer, and the frost layer is thick, which affects the
defrosting time.
The diameter of φ9.52 is large, the disturbance to the heat transfer boundary layer is small, and the heat transfer efficiency is low.

The Holtop HFM series SUSPENDED DX AIR HANDLING UNIT uses R410A as refrigerant, with zero ODP, to avoid damage to the ozone layer and at the same time, greatly improve cooling capacity. 

The whole unit uses frameless foaming boards to construct, and self-tapping screws to connect these boards, making it very easy to be disassembled for maintenance.  

The indoor unit generates a high ESP, making it possible to cover the whole area to avoid uneven distribution of temperature. Such feature makes solution and design much easier.  

Even at 15°C, the cooling function can be activated normally; Heating function can be activated at -10°C in winter. 

The HFM outdoor unit can work with both return air and fresh air Indoor unit, to meet different customers’ needs.