General Description

iHAHU unit is an ideal air handling terminal unit for suspended ceiling installation and suitable for ducted air distribution. It is constructed of sandwich panels to achieve low noise level during operation. iHAHU air handling unit is shipped completely assembled and motor wiring is introduced into the control box to reduce on-site installation time and manpower. Every unit is thoroughly inspected and tested to clear up potential problems during startup. The unit contains side panels that provide easy access to fans, motors and filters.

FRAMEWORK

A frameless structure is used. The panel is integrated folding steel structure and tested to ensure that there is no air leakage.

CASING

Casing is double skinned and basically consists of two panels with internal insulation. Each panel is 1” thick. The inner and outer panels are made of plane galvanized steel and pre-coated galvanized steel. The insulation consists of a high-pressure PU foam sandwiched in between to reinforce the panel.

FILTER

Filter is washable, double-layer acrylic nylon with aluminum frame. G4 (Merv 8) or F8 (Merv 14) filter is optional.

COOLING COIL

The Cooling Coil is standard Cu/Al 3/8” OD. The manifolds are made of steel with threaded connections. The Cooling Coil is provided with manual Air-Vent valve. The aluminum fins are pre-coated for protection by hydrophilic blue fin process. Coils are tested at 30 bar (435 PSI) and recommended operating at no more than 20 bar (300 PSI).

DRAIN PAN

Drain pan is made of single wall painting steel with 3/16″ insulation on outer wall. The drain pan extends the full length and width of the coil and is sloped for positive drainage and includes 3/4” male pipe threaded galvanized drain connector.

FAN SECTION

Fans are mainly constructed of housing, impeller, mounting feet, and DC motor. The housing is made of hot-dip galvanized steel. The side panel includes inlet cones whose inlet conditions are designed for optimum aerodynamics. The scroll is fixed on the side panel by spot welding. The wheel is made of hot-dip galvanized steel. The forward curved blades feature an advanced aerodynamic design for maximum efficiency and minimum noise level. The impeller is fixed on the center plate and on the end ring with riveting compression. The impeller is designed for maximum strength and can withstand continuous operation with maximum power. All impellers and motor are fully balanced according to ANSI/AMCA-204 standard. The mounting feet are made of galvanized steel sheet with unique technical to ensure adequate strength.

iHAHU fans are equipped with YZWWSL external rotor BLDC motor. The motor consists of motor body and BLDC driver, controlled by 0~10VDC or Modbus RS485. This new designed motor significantly reduces motor torque fluctuation, vibration and noise resulting in high efficiency, reliability and long-life operation.

CONTROL SYSTEM (W4 /W5type)

A 0~10VDC motor modulating signal is received from thermostat which is powered by R and C or by indoor room terminals Vsp and GND. If the input signal is greater than 2Vdc, the unit is turned on. If the control signal is lower than 1.5VDC, the unit is turned off. Motor speed changes from 2~9.5VDC input signal. Motor RPM can be set from 300~1500. The unit is equipped with a 40VA 240~24VAC transformer as standard which supplies 24VAC power input to thermostat and other devices. The transformer is approved by ETL.

Microprocessor controls (EC-S8 type)

The main design features include:
~ 2-pipe, 2-pipe with booster electric heat, 2-pipe with primary electric heat, 4-pipe with 6 way valve installed. ~ Cool, Heat, Auto, Dehumidifier and Fan modes.
~ Sleep, Auto-Fan, Daily Timer, Auto-Restart with memory functions.
~ User friendly remote control handset.
~ Heat and cool temperature protections and safety cut out.
~ 2-way and 3-way on/off or modulating valve control.
~ Wired wall pad controller (optional)
~ Manual control panel in cabinet.
~ Auxiliary switch for cooling and heating signal.
~ Occupancy (remote on/off) contacts / economy mode contacts.
~ Open Modbus communication protocol.

Variable water flow system

Thewaterflowthroughthefancoiliscontrolledbyatemperaturedifferencebetweentheflowandreturnpipework – referredtoas Δt, toensurethecorrectheattransferfromthewatertotheair.Constant Δtkeeptheunitrunningefficiencyandconsequentlythewholelife running costs of the system.

SRCS2021 iHAHU-V/P-ECM-001

Accessories

Optional accessories can be selected: G4 (Merv 8) filter module, Mixing and recirculating chamber, 0~10V Modulating 2-way valve kit, On/Off 2-way valve kit, On/Off 3-way valve kit, Electrical heating module, AC/EC thermostat, AQI control PCB-S5, Complete function PCB-S6, Wired wall pad, Differential pressure transducer.