Piping Insulation Guidelines

13. The vent outlet MUST be installed to terminate in the same

atmospheric pressure zone as the combustion air inlet.

14.The vent system can be installed in an existing unused chimney provided that:

•Both the exhaust vent and air intake run the length of the chimney.

•No other gas fired appliance or fireplace (solid fuel) is vented into the chimney.

•The top of the chimney MUST be sealed flush or crowned up to seal against rain or melting snow so ONLY the piping protrudes.

•The termination clearances shown in Figure 7 are main- tained.

15.Furnace applications with vertical vents requiring vent di-

ameter increaser fittings must have increaser fittings

installed in vertical portion of the vent. Condensate will be trapped in the vent if the vent diameter is increased prior to having an elbow turned upward. This could cause nui- sance tripping of the pressure switch.

NOTE: Use closed cell, neoprene insulation or equivalent. If Fi- berglass or equivalent insulation is used it must have a vapor bar- rier. Use R values of 7 up to 10', R-11 if exposure exceeds 10'. If Fiberglass insulation is used, exterior to the structure, the pipe MUST be boxed in and sealed against moisture.

When the vent or combustion air pipe height above the roof exceeds 30", or if an exterior vertical riser is used on a hori- zontal vent to get above snow levels, the exterior portion MUST be insulated.

When combustion air inlet piping is installed above a sus- pended ceiling, the pipe MUST be insulated with moisture resistant insulation such as Armaflex or other equivalent type of insulation.

Insulate combustion air inlet piping when run in warm, hu- mid spaces such as basements.

Sizing Combustion Air and Vent Pipe

Consult Table 3 or Table 4 to select the proper diameter exhaust

and combustion air piping. Exhaust and combustion air piping is sized for each furnace Btuh size based on total lineal vent length (on inlet or outlet side), and number of 90 ° elbows required. Two 45 ° elbows can be substituted for one 90 ° elbow. The elbow or el-

bows used for vent termination outside the structure ARE counted, including elbows needed to bring termination above ex- pected snow levels. The elbow inside the furnace on the *9MPD IS NOT included in the count.

Pipe Diameter Table

N9MP1 & *9MPD Models

50,000, 75,000 & 80,000 Btuh Furnaces

40'& (5) 90 ° elbows with 2" PVC pipe or 70'& (5) 90 ° elbows with 3" PVC pipe

100,000 Btuh Furnace

40'& (5) 90 ° elbows with 3" PVC pipe or 70'& (5) 90 ° elbows with 3" PVC pipe & Long Vent Kit (See Tech. Manual)

125,000 Btuh Furnace

40'& (5) 90 ° elbows with 3" PVC pipe

Elbows are DWV Long Radius Type for 2" and 3" vents,

If more than five elbows are required, reduce the length of

both the inlet and exhaust pipes 5' for each additional elbow used.

NOTE: It is allowable to use larger diameter pipe and fitting than shown in the tables but not smaller diameters than shown.

Pipe Diameter Table

N9MP2 Models

50,000 & 80,000 Btuh Furnaces

40'& (5) 90 ° elbows with 2" PVC pipe or 70'& (5) 90 ° elbows with 3" PVC pipe

75,000 Btuh Furnaces

25'& (3) 90 ° elbows with 2" PVC pipe or 40'& (5) 90 ° elbows with 2" PVC pipe & Long Vent Kit (See Tech. Manual) or 70'& (5) 90 ° elbows with 3" PVC pipe

100,000 Btuh Furnace

40'& (5) 90 ° elbows with 3" PVC pipe or 70'& (5) 90 ° elbows with 3" PVC pipe & Long Vent Kit (See Tech. Manual)

125,000 Btuh Furnace

40'& (5) 90 ° elbows with 3" PVC pipe

Elbows are DWV Long Radius Type for 2" and 3" vents.

If more than five elbows are required, reduce the length of

both the inlet and exhaust pipes 5' for each additional elbow used.

For "Concentric Termination Kit" Venting table, see

"Section 11" in this manual.

Vent Termination Clearances

CARBON MONOXIDE POISONING, FIRE AND EXPLO- SION HAZARD

Inlet and outlet pipes may NOT be vented directly above each other.

Failure to properly vent this furnace can result in death,

personal injury and/or property damage.

1.Determine termination locations based on clearances spe-

cified in following steps and as shown in Figure 7, Figure 19, through Figure 27.

For "Concentric Termination Kit" clearances, see Figure 45,

Figure 46, Figure 47, Figure 48 and Figure 49 in "Section 10" in this manual.

2.The vent termination must be located at least 12" above

ground or normally expected snow accumulation levels.

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9MPD, N9MP1, N9MP2 specifications

The Sears N9MP2, N9MP1, and 9MPD are prominent models in the realm of residential heating systems, specifically designed to provide efficient and effective heating solutions. These models are part of Sears' commitment to quality and innovation, making them a popular choice among homeowners seeking reliability and performance.

The N9MP2 is a high-efficiency multi-speed gas furnace that boasts an impressive AFUE (Annual Fuel Utilization Efficiency) rating. This feature allows the furnace to convert a significant portion of fuel into usable heat, which effectively translates to lower energy bills for homeowners. The unit is equipped with a two-stage gas valve that provides increased comfort by adjusting the heating output based on demand, ensuring an even temperature throughout the home.

The N9MP1, like its counterpart, is known for its reliability and efficiency. It offers a single-stage operation that is ideal for homes needing consistent heating without the necessity for the more complex stages present in two-stage systems. This model also has a good AFUE rating, making it a cost-effective solution for families looking to reduce their heating expenses. Its design is tailored for easy installation and maintenance, allowing homeowners to keep their heating systems running at optimal performance without hassle.

The 9MPD model takes a step further with its advanced technology integration. It features a sophisticated control board that allows for easier diagnostics and enhanced system management. The 9MPD is also designed with quiet operation in mind, employing advanced sound-reduction technologies to minimize noise levels during heating cycles. Homeowners will appreciate the peace and quiet it brings, particularly in shared living spaces.

All three models are equipped with high-quality insulation and specialized heat exchangers that enhance their thermal efficiency. Additionally, they are designed with safety features such as automatic shut-off systems and robust flame rollout protection, ensuring a safe heating experience.

In terms of characteristics, these models are generally constructed with durable materials, designed to endure harsh weather conditions while providing consistent heating. They can be connected to various home automation systems, which adds to their appeal for tech-savvy consumers.

In conclusion, the Sears N9MP2, N9MP1, and 9MPD represent a comprehensive lineup of reliable, efficient, and technologically advanced heating systems suitable for contemporary homes. Their dedication to performance ensures that homeowners enjoy a warm and energy-efficient environment throughout the chilly seasons.

Sears N9MP2, N9MP1, 9MPD manual Piping Insulation Guidelines, Sizing Combustion Air and Vent Pipe

Models: 9MPD N9MP1 N9MP2