6. The furnace must be installed downstream from or on the
POSITIVE PRESSURE SIDE
of the air
circulating blower
7. Air flow through the furnace may be in either direction. However, on units with an air distribution baffle assembly, the
air flow must enter the furnace from the baffle side. If entering air is desired from the opposite side, the baffle
assembly must be relocated to that side of the heat exchanger. High SCFM models do not require this baffle
assembly and are recognized by the suffix letter “H” in the furnace model number. (Example: IHRDV-400
H
ME).
8. High SCFM model furnaces require heating air temperature rise be maintained at between 10º to 60º F. On units with
the baffle assembly temperature rise must be maintained between 40º to 100º F.
9. Filters, if used, must be cleaned or replaced as often as is necessary so as not to restrict air delivery.
10. Furnaces installed in areas of high air contamination may require FREQUENT cleaning. Refer to section on
CLEANING for recommended frequency..
11. The (I) (IS) HRDV furnaces are design certified for operation with modulating or two-stage gas controls. When either
modulating or two-stage controls are ordered, a thermostatic type fan control switch must NOT be used. With these
gas controls, constant fan operation, simultaneous fan and gas valve operation, or a fan time delay relay must be
employed.
12. If a fan control is not used, the blower must operate continuously or whenever the gas valve opens.
NOTE: AS AN ADDED PRECAUTION, INSTALL EITHER AN AIR PROVING SWITCH OR A
SINGLE POLE, NORMALLY OPEN RELAY IN THE ELECTRIC GAS VALVE CIRCUIT. THE
AIR PROVING SWITCH WOULD SENSE AIR CIRCULATION THROUGH THE SYSTEM.
THE RELAY WOULD BE ENERGIZED BY THE LOAD SIDE OF THE BLOWER MOTOR
STARTER. EITHER SWITCH WOULD THEN ACTIVATE THE GAS VALVE TO OPEN, BUT
ONLY WHEN THE BLOWER WAS OPERATING.
13. The high limit control switch is a safety control that provides protection if furnace overheats due to blower failure,
restricted air flow, or faulty controls. If unit overheats the limit switch breaks the circuit to the electric gas valve and
closes gas supply. When the temperature of the heat exchanger drops to a safe degree, the limit switch automatically
rests and permits the gas valve to open again. Cause of trouble must be corrected IMMEDIATELY to avoid serious
damage to the furnace. The limit switch is a safety control, NOT AN OPERATING CONTROL.
14. Special precautions for furnaces used in conjunction with AIR COOLING and MAKE-UP AIR SYSTEMS:
a. Type 409 STAINLESS STEEL heat exchangers may be used in all applications, but is recommended for make up
air systems where inlet air temperature is ABOVE 40º F.
b. If furnace is used in either make-up air or air cooling applications, significant quantities of condensate may form.
15. Field installed ductwork on the unit discharge end must be secured to the flanges on the heat exchanger and not on
unit front cabinet.
Failure to properly install could cause fire, explosion, damage to equipment or even death
.
16. Venting (I) ISHRDV indoor duct furnaces. Venting must be installed by a qualified installer in accordance with all local
codes. In the absence of local codes, venting must be installed in accordance with the latest edition of the National
Fuel Gas Code, ANSI Z223.1/NFPA#70, Part 7, venting of equipment. In Canada, venting must be in accordance
with the latest edition of the Natural Gas Installation Code CAN/CGA-B149.1; propane installation code CAN./CGA-
BA49.2. A bult-in power venter is provided – do not connect into any additional mechanical draft systems operating
under a positive pressure. Improper installation can create a hazardous condition such as explosion, fire, carbon
monoxide poisoning, resulting in property damage, personal injury or death.
C. INSTALLATION:
·
Regulations:
Installation of this appliance must conform to applicable federal, state, and local codes and regulations, and with guidelines established by
A.G.A (American Gas Association), NFPA(National Fire Protection Association), N.E.C. (National Electrical Code), the National Board of Fire
Underwriters and CAN/CGA B149. Listed are codes appearing in this text, the Associations, and their addresses where they may be
obtained.
1. The National Fuel Gas Code
2. All NFPA codes, National Electrical Code
Contact: American Gas Association (Administrative)
Contact: National Fire Protection Association, Inc.
1515 Wilson Boulevard
Batterymarch Park
Arlington, Virginia 22209
Quincy, Massachusetts 02269
3. Standard of National Board of Fire Underwriters
4. Canadian Gas Association
Contact: National Board of Fire Underwriters
Contact: Canadian Gas Association
85 John Street
178 Rexdale Boulevard
New York, New York 10036
Etobicoke, Ontario, Canada M9W 1R3
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