Reznor's HRPD Rooftop Dual Duct Furnaces are designed to be used in series: as the heating component in either a heating, heating/cooling, or makeup air system. Each of the dual furnaces is certified for 80% thermal efficiency for use with either natural or propane gas, as specified.

Eight sizes are available from 250,000 through 800,000 BTUH input. Each furnace includes an integral power vent system which provides metered combustion air, dilutes flue products, and eliminates the need for vent caps. The weatherized, aluminized steel cabinets are mounted on 12 gauge zinc grip rails designed for setting directly on a roof or slab surface.  Note: A separate blower system, such as Reznor Model RBL, is required for air delivery

Heating Range ( MBH )

Airflow Range ( CFM )

Heating Efficiency ( Gross )


  • Orifices for natural gas
  • Aluminized steel heat exchangers (When inlet air temperatureis below 40F or temperature rise is less than 40F,optional stainless steel heat exchanger is recommended.)
  • Aluminized steel burners with stainless steel insert
  • 120-volt supply voltage
  • 24-volt control voltage transformers
  • Redundant, single-stage combination gas valves
  • Spark-ignited intermittent safety pilots with electronic flamesupervision
  • High limit safety cutouts
  • Power venters
  • Differential air pressure switches to verify vent flow
  • Terminal block wiring
  • Fan Control
  • Left side access for burners and controls (slide out burnerdrawers)
  • Weatherized cabinet with interlocking joints and mounting rails

Optional Features - Factory Installed

  • Orifices for propane gas
  • Elevations to 9,000 ft
  • 409 or 321 stainless steel heat exchangers
  • 409 stainless steel burners
  • 409 stainless steel bottom pans
  • Burner Controls for Recirculated Heating
    • Two-stage gas valve on each furnace (operate intandem from 2-stage room thermostat)
    • Electronic modulation, 50-100% tandem operationfrom room thermostat
  • Gas Controls for Makeup Air
    • Two-stage operation with 1-stage gas valve and 2-stage ductstat (50 or 100%)
    • Four-stage operation with 2-stage gas valves controlledfrom 2-stage ductstats with either unit-mounted controlsor remote electronic controls with or without displaymodule
    • Mechanical modulation (50 to 100%) with unit-mountedcontrols (50-100F) with or without high fire bypass
    • 4:1 Turndown Electronic modulation (25% of fulloutput) with duct probe (55-90F) with unit setpoint, withremote adjustment, or with signal conditioner for customer-provided computer control
    • 8:1 Turndown Electronic modulation (12% of full fireoutput) 20-100% firing rate on first furnace controlledfrom ductstat with remote adjustment and 2-stage withoutside air stat on second furnace or same turndowncapability with signal conditioner for customer-providedcomputer control -- 8:1 turndown electronic modulationrequires stainless steel heat exchangers, burners, andbottom pans (8:1 turndown not available on Size 700)
  • Voltage supply, 208, 230, or 460 single phase
  • Intermittent spark pilots with timed lockout
  • Right side controls (right when facing airstream)
  • High and low gas pressure switches
  • Airflow proving switch
  • Curb cap base

Optional Features - Field Installed

  • Vent extension kits
  • 24V, one or two stage, heating only or heating/coolingthermostats
  • Room override thermostat for electronic modulation
  • Thermostat guard with locking cover
  • Packaged switches, 2 or 3 position
  • Disconnect switch (UL listed)

2 Files


Duct Heater Marketing Catalog
Duct Heater Marketing Catalog
Download File
858.0 kB
Heating, Cooling, Ventilation & VRF Product Line
Heating, Cooling, Ventilation & VRF Product Line Sheet
Download File
630.7 kB

Technical Data
1 File

Technical Data

Catalog - Duct Heater
Duct heater catalog
Download File
1.6 MB

9 Files


Unit Installation Manual - Outdoor Duct Furnaces
Installation manual for Models RP & HRPD
Download File
1.3 MB
Parts Manuals - RP-RPBL-RPB-HRPD-RBL
Parts manual for Models RP, HRPD, RPB, RPBL, & RBL
Download File
2.3 MB
Field Service - Replacement Gear Motor Kit
Instructions for installing replacement gear motor kit for Models SC, SSCBL, HRPD, RP, RPB & RPBL
Download File
755.5 kB
Parts Manuals - Functional Replacement Fan/Blower Controls and Limit Controls
 Parts manual for functional replacement fan/blower controls and limit controls
Download File
322.8 kB
Field Service - Replacement Relay Kit - PN 259521
Replacement relay kit for Reznor part number 259521 - applies to power vented units using Reznor part number 46233 or 259518 time delay relay
Download File
646.2 kB
Field Service - Ignition Control Replacement - Various Models
Ignition control replacement kit for pilot code 62, 63, 65, 66, & 84 (found in first set of digitis of serial number)
Download File
250.4 kB
Field Service - Replacment Relay Kit - PN 262375
Replacement relay kit for Reznor part number 262375, applies to all power vented units using Reznor part number 206146 time delay relay
Download File
1.2 MB
Field Service - Replacement of Discontinued Relays
Installation for kits designed to replace relays no longer available from suppliers. Applies to all Reznor units using obsolete relays.
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340.4 kB
Unit Installation Manual - Chauffe-conduits - Instructions D'Installation
Installation / Fonctionnement / Entretien Application: chauffe-conduits extérieursséries RP et HRPD
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1.2 MB

Other Files
1 File

Other Files

Warranty Statement
Reznor equipment limited warranty statement
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183.4 kB