Filter
Top Products
Rinnai Corporation Hydronic Furnace (37AHB) Manual 31
Table 4: Hydronic Furnace’s Specifications
UNIT MODELS
37AHB04508KA5 37AHB06012KA5 37AHB07514KA5 37AHB09016KA5
Trade Name
AHB45 AHB60 AHB75 AHB90
RATING AND PERFORMANCE Descriptor (Typ.)
Nominal Output Capacity (BTU/h) † 45,000 60,000 75,000 90,000
Air Side Temperature Rise Rate in
o
F
( 68ºF Entering Air @ 150ºF Entering Water)
Heat Speed 50 50 50 50
External Static Pressure (in. W.C.) 0 to 1.0 0 to 1.0 0 to 1.0 0 to 1.0
Nominal Airflow (CFM)
Heating 800 ‡ 1200 ‡ 1400 ‡ 1600 ‡
Cooling Range 650 - 800 650 - 1200 1000 - 1600 1200 - 1750
ELECTRICAL
Power Supply V - HZ - PH 115-60-1
Minimum Circuit Ampacity MCA 9.6 9.6 12.43 16.2
Max. Rating of Overcurrent Protective Device MOP (Calculated) 13.6 13.6 18 23.7
Maximum Fuse or CKT BKR Size Amps 15 15 20 25
Transformer (24V) 40 VA (Primary: 120 VAC / Secondary: 24 VAC)
Printed Circuit Board PCB
INTEGRAL (with connections for A/C system, UV lamp, Humidifier, and
electronic air cleaner)
CONTROLS
Available Unit Configurations
A/C or HP Dip Switch Selectable (SW1)
Single or Two Stage Dip Switch Selectable (SW1)
FS or WH Shunt Selectable (P-7)
Safety Door Switch
Rated Voltage 125 VAC
Resistive Load 21 Amp
Blower Off Delay HTG/CLG Dip-switch Selectable/Fixed 30 Sec
Cool / Heat Blower On Delay Varies Cool: 1 second / Heat: 25 seconds (see Sequence of Operations)
INDOOR BLOWER MOTOR
Type DIRECT DRIVE MOTOR (ECM)
Motor HP 1/2 1/2 3/4 1
Motor (Full Load Amps) FLA 6.2 6.2 8.5 11.5
Run Capacitor mfd/volts N/A N/A
Volts-PH-HZ 115-1-60
CIRCULATING PUMP
Type
Wet Rotor
Volts-PH-HZ
115-1-60
Motor (Full Load Amps/Locked Rotor Amps)
FLA/LRA
1.8 / 2.6
Pump Motor HP
1/8
Run Capacitor mfd/volts 14/250
Maximum Working Pressure PSI 125
Min/Max Fluid Temperature ºF (ºC) 120 (49) / 160 (71)
HYDRONIC HEATING COIL
Coil Construction 3/8" OD copper tubes, aluminum fins, galvanized steel frame
Rows...Fins/In 2…16 2…16 3…14 3…15
Total Face Area Sq. Ft. 2.3 2.6 2.8 3.3
Approximate Internal Volume Gallons 0.47 0.53 0.86 1.02
PIPING CONNECTIONS - (QTY)
Type Copper Stubs
Supply Diameter Inches (1) 3/4
Return Diameter Inches (1) 3/4
RETURN-AIR FILTERS
Filter Type (Throwaway) Inches †† 12 X 20 X 1 16 X 20 X 1 20 X 20 X 1 (2) 12 X 20 X 1
UNIT WEIGHT
Shipping lbs 92 109 118 136
Installed (with water) lbs 107 127 138 159
† Tested in accordance with ANSI/ASHRAE Standard 37-Latest edition.
‡ Airflows shown are nominal (blower speeds are factory set). For air delivery
other than stated, refer to Air Delivery & Performance table.
†† Required filter sizes shown are based on the larger of the AHRI (Air
Conditioning & Refrigeration Institute) rated cooling airflow or the heating
airflow velocity of 300 ft/min for throwaway type or 450 ft/min for high-
capacity type.
Side intake filter to be (1) 20”x20”x1” typical for all models.
Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.
Rinnai is continually updating and improving products. Therefore, specifications are subject to change without prior notice.