16.0) VENTING

CARBON MONOXIDE HAZARD

Heaters installed in an unvented mode require a minimum ventilation flow of 4 CFM per 1,000 Btu/hr of total installed capacity.

In buildings with airborne contamination such as poultry houses the heater must be installed with fresh air for combustion.

Failure to do so may result in death, serious injury, property damage or illness from Carbon Monoxide poisoning.

A.BASIC FLUE VENTING — Venting must comply with the latest edition of the National Fuel Gas Code (ANSI Z223.1-latest edition) or the authority having jurisdiction. Other venting references are in the equipment volume of the ASHRAE Handbook.

Model

Heat

Maximum vent length ft.

Maximum Fresh air

Max. combination of

 

exchanger

(4” diameter)

intake length ft (4”

fresh air and vent ft. (4”

 

length ft

 

diameter)

diameter)

PTS/U 40/25

20

45

50

75

PTS/U 50/30

20

45

50

75

PTS/U 50/30

30

35

40

65

PTS/U 75/50

20

45

50

75

PTS/U 75/50

30

35

40

65

PTS/U 100/65

30

45

50

75

PTS/U 100/65

40

35

40

65

PTS/U 125/80

30

60

50

75

PTS/U 125/80

40

50

40

65

PTS/U 125/80

50

40

30

55

PTS/U 150/100

40

60

50

75

PTS/U 150/100

50

50

40

65

PTS/U 150/100

60

40

30

55

PTS/U 175/110

50

60

50

75

PTS/U 175/110￿

60

50

40

65

PTS/U 175/110￿

70

40

30

55

PTS/U 175/110￿

50

60

40

65

PTS/U 200/125

60

50

30

55

PTS/U 200/125￿

70

40

30

45

Vent lengths shown in the table are for horizontal and vertical venting. If a longer length of vertical or horizontal venting is required contact the manufacturer for assistance with vent sizing.

SINGLE HEATER VENTING (VERTICAL THROUGH THE ROOF)

1.When venting the heater to outside of building through a roof, use single-wall metal pipe. This is to be constructed of galvanized sheet metal or other approved noncombustible corrosion-resistant material as allowed by state or local codes.

2.A vent passing through a combustible roof shall extend through an approved clearance roof thimble. Double-wall, Type B vent must be used for the portion of the vent system which passes through the roof. An approved vent cap (Leslie “VersaCap”-Type B or equal) must be attached to end of the flue.

3.The maximum equivalent length of vent pipe should be carefully observed. A safety switch in the heater is designed to shut the heater off before excessive flue restriction causes bad combustion. Refer to the Vent Sizing Table for maximum vent lengths and vent pipe diameter.

4.Joints between sections of piping shall be fastened by sheet metal screws or other approved means and should be sealed to prevent leakage of flue gas into building. Aluminum or Teflon tape suitable for 550ºF (3M Company tapes 433 or 363) or silicone sealant is recommended.

5.All portions of the vent pipe shall be supported to prevent from sagging (6’ spacing is recommended).

6.When the vent pipe passes through areas where the ambient temperature is likely to induce condensation of

 

Form #43343530

–34–

JJuly 08

Page 35
Image 35
Gas-Fired Products 100, N7/L7, 40, 150, 175, 200 manual Single Heater Venting Vertical Through the Roof