Nordyne SERIES M1B Manuel D’Utilisation

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CIRCULATING AIR REQUIREMENTS
 WARNING:
Do not allow combustion products 
to enter the circulating air supply. 
Failure to prevent the circulation 
of combustion products into the 
living space can create potentially 
hazardous conditions including 
carbon monoxide poisoning that 
could result in personal injury or 
death.
All return ductwork must be secured 
to the furnace with sheet metal screws. 
For installations in confi ned spaces, 
all return ductwork must be adequately 
sealed. The joint between the furnace 
and the return air plenum must be 
air tight.
The surface that the furnace is 
mounted on must provide sound 
physical support of the furnace with 
no gaps, cracks or sagging between 
the furnace and the fl oor or platform.
Return air and circulating air ductwork 
must not be connected to any other 
heat  producing  device  such  as  a 
fireplace insert, stove, etc. This 
may result in fi re, explosion, carbon 
monoxide poisoning, personal injury, 
or property damage.
Return Air Connections
U.S.A. home manufacturers shall comply with 
all of the following conditions to have acceptable 
return air systems for closet installed forced air 
heating appliances:
•  The return air opening into the closet shall not 
be less than specifi ed in the appliance’s listing.
•  The cross-sectional area of the return duct 
system leading into the closet, when located 
in the fl oor or ceiling shall not be less than 235 
square inches (or 390 square inches for 5 ton 
ready M1/M5 Furnaces).
 CAUTION:
HAZARD OF ASPHYXIATION: Do not 
cover or restrict return air opening.
• Means shall be provided that prevent 
inadvertent closure of fl at objects placed over 
the return air opening located in the fl oor of the 
closet (versus the vertical front or side wall).
•  The total free area of openings in the fl oor or 
ceiling registers serving the return air duct 
system must be at least 235 sq. in. At least 
one register should be located where it is not 
likely to be covered by carpeting, boxes and 
other objects.
•  Materials located in the return duct system 
must have a fl ame spread classifi cation of 
200 or less. This includes a closet door if the 
furnace is in a closet.
• Noncombustible pans having 1” upturned 
fl anges are located beneath openings in a 
fl oor duct system.
•  Wiring materials located in the return duct 
system shall conform to Articles 300-22 of the 
National Electrical Code (ANSI C1/NFPA-70).
•  Gas piping is not run in or through the return 
duct system.
 CAUTION:
HAZARD OF ASPHYXIATION: 
Negative pressure inside the 
closet, with closet door closed 
and the furnace blower operating 
on high speed, shall be no more 
negative than minus 0.05 inch 
water column.
•  Test the negative pressure in the closet with 
the air-circulating fan operating at high speed 
and the closet closed. The negative pressure is 
to be no more negative than minus 0.05 inch 
water column.
•  Air conditioning systems may require more 
duct register and open louver area to ob-
tain necessary airflow. Use NORDYNE’s 
certiduct program to determine proper duct 
size for A/C.
Supply Air Connections
For proper air distribution, the supply duct system 
must be designed so that the static pressure 
measured external to the furnace does not 
exceed the listed static pressure rating shown 
on the furnace rating plate.