Sapphire Audio DV425TR owner manual VERTICAL INSTALLATION, cont, Step

DV425TR DIRECT VENT ROOM HEATER

VERTICAL INSTALLATION, cont.

Step 7.

Continue to assemble pipe sections until the height of the vent cap (H) (Figure 15) meets the minimum code requirements as outlined in the current CAN/CGA-B149 Installation Codes (in Canada), the National Fuel Gas Code NFPA 54/ANSI Z223.1 (in USA), or local codes. Note that for steep roof pitches, the vent height must be increased.

See Table 1 below. In high wind conditions, nearby trees adjoining rooflines, steep pitched roofs, and other similar factors can result in poor draft, or down drafting. In these cases increasing the vent height may solve this problem.

Fig. 15

H

Dimension "H"

Obtained From

Table 1

TABLE 1

	MINIMUM HEIGHT
ROOF PITCH	FEET	METERS
Flat to 7/12	1	0.30
Over 7/12 to 8/12	1.5	0.46
Over 8/12 to 9/12	2	0.61
Over 9/12 to 10/12	2.5	0.76
Over 10/12 to 11/12	3.25	0.99
Over 12/12 to 14/12	5	1.52
Over 14/12 to 16/12	6	1.83
Over 16/12 to 18/12	7	2.13
Over 18/12 to 20/12	7.5	2.29
Over 20/12 to 21/12	8	2.44

The height of the vent cap must meet the minimum building code requirements described above.

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