VENTING

Venting

1.Flue pipe must be as large as the flue collar on the draft diverter.

2.Maintain an upward slope of at least 1/4 inch (6mm) per foot of horizontal run.

3.Run flue pipe as directly as possible with a minimum of elbows.

4.Flue pipe should extend through the wall of a chimney to be flush with inner wall.

5.Flue pipe must be adequately supported by metal straps.

6.Single wall vent pipe may be attached directly to the draft hood of the fireplace heater when a clearance of 2 1/2 inches (64mm) is maintained between the single wall vent pipe and the combustible wall of the room in which the fireplace heater is located. Use double wall vent pipe for clearances less than 2 1/2 inches (64mm) to combustibles.

7.For flue pipe running through walls and roof, use B-1 [1 inch (25mm) clearance to combustibles] vent pipe.

8.Chimneys should extend at least 2 feet (.6m) above the roof and above any object or nearby building within 10 feet (3m).

9.Open tees should not be used in the flue pipe.

10.Appliance must not be connected to a chimney flue that is servicing a separate solid-fuel burning appliance.

For proper venting, do not attach a 90° elbow directly to draft diverter. If possible, attach 2 feet (.6m) of straight vent pipe before an elbow is used. Use of 45° elbows is recommended.

Uninsulated single-wall metal pipe shall not be used outdoors in cold climates for venting gas utilization equipment.

Ventilation and Combustion Air

Fireplace heaters shall be installed in a location in which the facilities for ventilation permit satisfactory combustion of gas and proper venting under normal conditions. In buildings of conventional frame, brick or stone construction without tight storm windows and doors, infiltration is normally adequate to provide for combustion and draft hood dilution.

Where appliances are installed in a confined space within a building, the building being of unusually tight construction, air for combustion and ventilation must be obtained directly from outdoors or from such spaces that freely communicate with the outdoors. Under these conditions, the confined space shall be provided with two permanent openings, one near the top of the enclosure and one near the bottom; each opening shall have a free area of not less than one square inch (6.5cm2) per 1,000 BTU's (.3KW) of total input. The draft hood must be in the same atmospheric pressure

zone as the combustion air inlet to the appliance and shall be so located so that the relief opening is accessible for checking vent operation.

Liner and Insulated Liner

When you install a vented fireplace heater into a masonry chimney you must follow these steps.

1.The chimney must be lined and sized properly. Most masonry chimneys are over sized and absorb too much heat to be considered a proper vent. If you have any doubts line the chimney with the right size liner. If it's unlined you must line it.

2.Use an insulated liner when the chimney is on the outside, three sides exposed to the weather, and there is no clay liner in the chimney. The insulation will help keep the flue gases warmer.

Insulated Vent Enclosure (Figure 15)

Vented fireplace heaters installed with the vent going directly to the outside and above the eaves can cause poor venting. The cold pipe will have a delay in proper venting and cause the fireplace heater to shut "off" by the vent safety switch. To prevent delayed venting as well as condensation of flue products an insulated enclosure is recommended.

Use type B 4" (102mm) diameter vent pipe and maintain at least a one inch (25mm) clearance to combustibles.

Use metal thimble to protect vent pipe as it passes through combustibles

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Figure 15

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Image 15
Empire Comfort Systems pmn manual Venting, Liner and Insulated Liner, Insulated Vent Enclosure Figure