Electric Duct HeatersIDHB & IDHC SeriesMay20141
Duct HeatersGreenheck has a complete line of configurable electric duct heaters that are perfectly suitedto your HVAC application. Our CAPS configuration tool helps you save time with its industryleading selection speed and information packed submittals. With quick lead times and aproven history of on time shipping, we can ensure that your heater will be available whenyou need it. Experience the difference by choosing Greenheck duct heaters for your project.ApplicationsGreenheck duct heaters are used in forced air applications to provide dedicated space heat or to supplementexisting heating systems. Typical applications are: Space heating Primary heating Secondary and/or auxiliary heating Reheat Multi-zone and VAV systems ReplacementModels: IDHB & IDHCGreenheck offers two heater styles: IDHB and IDHCseries. All heaters are factory assembled and wiredfor 50/60 Hertz.Both models feature: Fan interlock Ground lugs Automatic limit switch for primary overtemperature protection Manual reset limit switch for secondary overtemperature protection Disconnecting contactor Power terminal board Control panel constructed of heavy gaugecorrosion resistant steel Control terminal board Left hand offset control box (standard) Control components secured to a raised plate UL 1996 Listed 105 C appliance wireIDHB SeriesIDHC Series2
IDHB & IDHCTwo frame types are available: Slip in - allows you to slip the heater into the opening in the ductwork. Flange - allows you to bolt into place between two sections of flanged duct.FlangeSlip mentsTerminal orControl BoxTerminal orControl BoxWhy would I choose Greenheck heaters versus other brands?We provide: Bi-directional airflow in horizontally mounted applications Hinged access cover with latch All limit controls are resettable Proven wire rack system provides very low pressure drop and extended element life Zero clearance rating for installations into ducts All components (except the SCR) are mounted inside the control panelIDHBIDHCVoltages/Stages120/1 - 480/3 120/1 - 575/3Capacity0.5 - 39.9 kW 0.5 - 500 kWMinimum Size8x88x8Maximum Size36 x 36120 x 144Controls1 or 2 stageStagePneumaticStepSCR controlVernier SCR (Larger kW)PneumaticThermostatRoomRoomDuct3
Options/AccessoriesControl Panel Removable hinged access door with latch(standard) Detailed wiring diagram Configurable with left or right offsetAvailable options: Dust tight construction with gasketed cover andsealed seams Vapor barrier Recess for internally insulated ducts Flush mount configuration1 - Airflow SwitchFan Interlock switch (standard/UL required)Optional airflow switch senses air pressure acrossthe heater surface closing the electrical switchand allowing the heater to activate. This switch isavailable with fixed or adjustable set point.82 - Disconnect SwitchA door interlocking disconnect switch is used toprevent the control door from being opened untilpower to the heater is disconnected.3 - Power FusingUL and NEC codes require heaters in excess of48 amps be subdivided into circuits of 48 amps orless. If 48 amps or greater, fusing comes standard.Less than 48 amps, fusing is optional.4 - Terminal BlocksTerminal blocks are standard on all heaters for quickand easy integration with field installed controlwiring.5 - ContactorsDisconnecting contactors break all ungrounded lineson UL listed duct heaters and are UL approved for250,000 cycles. There are two types available: Magnetic - standard for all heaters Mercury - used where silent operation and/orfrequent cycling is desired (optional)47
Options/Accessories6 - Control TransformerControl transformers are used to provide single pointwiring when the control voltage differs from the linevoltage. The transformer is available as fused orunfused.7 - Capacity Controls12Staged ControlOne to four stages are provided standard.PneumaticPneumatic controls allow a pneumatic buildingcontrol system to operate heaters with up to threestages. An airflow switch is standard with this option.Proportional Controls6354Model IDHC is available with the followingproportional control options which are compatiblewith a 0-10Vdc or 4-20mA analog signal from a BMS,Room or Duct T-stat.Electronic Step ControllerAn electronic step controller provides electronicsequencing control of an electric duct heater upto 12 steps. When interruption of power occurs allstages cycle off. Upon restoration of power the stepsequence resumes.SCR (pictured)Solid state relays are used to provide continuousmodulation. SCR is the most precise form of heatercontrol.Vernier SCR (Step and SCR)Vernier SCR control combines the benefits of Stepand SCR control to provide precise proportionalcontrol on heaters in excess of 135 amps.8 - ElementsStandard heater elements are 60% Ni grade C wirewhich exhibit excellent performance in standardapplications. Elements are supported with a wirerack system that significantly reduces element sagand pressure drop. Optional features include: 80/20 NiCr, grade A element wire provides superiorcorrosion resistance in reheat and high humidityapplications Derated coils aid in longer element life in singleand multi-zone air handler applications5
OptionsPilot LightPilot lights are installed on the side panel and usedto indicate heater conditions as follows:- heater energized- step energized- airflow switch open Available with 24V or 120V control voltagesTime Delay RelayA time delay relay provides a delay of 30 to 60seconds when energizing or de-energizing the circuitcontrolled. Standard control voltages are 24V through 277VPressure Electric Switches (PE)A PE switch is used to control the heater with apneumatic air signal. Requires field adjustment for specific jobrequirementsThermostatRoom stat - Controls heater to maintain adjustablespace temperature when heater is usedas primary heating methodDuct stat - Controls heater to maintain adjustabledischarge temperature. This is thepreferred method of control for preheatand reheat applications. This option isonly available with SCR, Vernier SCR, orStep controller systems.Heater Selection – This diagram shows typical information that you will need when selecting a duct heater.DimensionsWidthHeight6Mounting TypeSlip-inFlangedCapacity (kW)Given orCalculated
Performance DataMinimum Air Velocities22,00020,00016,000NLETAIRAIRINLFI0 F91 TO110 BE10,000TO9LOW78 F12,000INLETETAIR14,00078 WATTS PER SQUARE FOOT, DUCT 001,400Velocity (fpm)Static Pressure Drop - inchesof water (w.g.)Pressure Drop Through Heater4.16.14GeneralA. The minimum airflow through a duct heateris directly related to the inlet air temperature.Consideration must be given to both airflow acrossthe heater and the inlet temperature.B. To calculate the watts per sq. ft. (square foot) of ductarea, divide the total watts required by the duct size(Watt density watts/duct area (ft2).Example: Duct size equal 2 ft. x 3 ft., total wattsequal 20,000 watts per sq. ft.20,000 33336C. If airflow in the duct is expressed in FPM, then adirect cross reference can be made by comparingthe temperature of the air (as it enters the ductheater) to the kW rating on the table at the rated airvelocity.1. Draw a line horizontally from the watts per sq. ftrequired to the inlet air temperature being used.2. From this point of intersection on the inlettemperature line, draw a line down vertically toestablish the air velocity.3. In cases where the velocity is less than thatdetermined from the chart, then the velocity mustbe increased, the kW required must be reduced,or both must be done.D. In cases where the airflow is expressed in CFM,convert to FPM by dividing the CFM by the ductarea.CFM FPMDuct Area(ft2)3.12.102.08.06.041.02200 4006008001,000 1,200 1,400 1,600 1,800 2,000 2,200Air Velocity - FPM1, 2, 3 and 4 - the number of rows of heater coils.When the number of rows of heater coils is unknown, assume 4.Power SourceVoltagePhaseControl TypeAccessoriesStagedSteppedProportional7
Formula for Calculating Line CurrentsSingle PhaseAMPS WATTSLINE VOLTAGETO CONVERT “kW” TO WATTSMULTIPLY “kW” BY 1,000Three PhaseAMPS WATTSLINE VOLTAGE x 1.73Line VoltageFactorLine Voltage x 1.73Capacity Calculator(Standard Air Conditions)208x1.73 359.8220x1.73 380.6230x1.73 397.9240x1.73 415.2440x1.73 761.2460x1.73 795.8480x1.73 830.4550x1.73 951.5600x1.73 1038.0kW CFM x 1.08 x T3414 T Temperature riseEnjoy Greenheck’s extraordinary service, before, during and after the sale.Greenheck offers added value to our wide selection of top performing, energy-efficient productsby providing several unique Greenheck service programs. Our Quick Delivery Program ensures shipment of our in-stock products within 24 hours ofplacing your order. Our Quick Build made-to-order products can be produced in 1-3-5-10-15or 25-day production cycles, depending upon their complexity. Greenheck’s free Computer Aided Product Selection program (CAPS), rated by many as thebest in the industry, helps you conveniently and efficiently select the right products for thechallenge at hand. Greenheck has been Green for a long time! Our energy-saving products and ongoingcorporate commitment to sustainability can help you qualify for LEED credits. Our 3D service allows you to download, at no charge, easy-to-use AutoDesk Revit 3Ddrawings for many of our ventilation products.Find out more about these special Greenheck services at greenheck.comOur CommitmentAs a result of our commitment to continuous improvement, Greenheck reserves the right to changespecifications without notice.Specific Greenheck product warranties are located on greenheck.com within the productarea tabs and in the Library under Warranties.8P.O. Box 410 Schofield, WI 54476-0410 Phone (715) 359-6171 greenheck.comPrepared to SupportGreen Building Efforts00.DMP.1015 R1 6-2014 IWCopyright 2014 Greenheck Fan Corp.