B. VENTING:

Fig. 7: Alternate constructions that allow reduced clearances to combustible materials.

REDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION:

Type of protection applied to and covering all surfaces of combustible material within the distance specified as the required clearance with no protection unless otherwise noted, all dimensions in inches, refer to Fig. 7.

Required clearance with no protection from the appliance or

18 inches

9 inches

6 inches

chimney connector is:

 

 

 

 

 

 

 

 

Ceiling

Wall

Ceiling

Wall

Ceiling

Wall

a.

3-1/2" thick masonry wall without ventilation air space….

--

12

--

6

--

5

b. 1/2" insulation board over 1" glass fiber or mineral wool batts…

12

9

6

5

4

3

c. 0.024(24 gauge) sheet metal over 1" glass fiber or mineral

9

6

5

3

3

3

wool batts reinforced with wire on rear face with ventilated air

 

 

 

 

 

 

space…

 

 

 

 

 

 

d.

3- 1/2" thick masonry wall with ventilation air space..

--

6

--

6

--

6

e.

0.024 (24 gauge) sheet metal with ventilated air space.

9

6

5

3

3

2

f. 1/2" thick insulation board with ventilation air space..

9

6

5

3

3

3

g. 0.024 ( 24 gauge) sheet metal with ventilated air space over

9

6

5

3

3

3

0.024 (24 gauge) sheet metal with ventilated air space….

 

 

 

 

 

 

h. 1" glass fiber or mineral wool batts sandwiched between two

9

6

5

3

3

3

sheets 0.024 (24 gauge) sheet metal with ventilated air space

 

 

 

 

 

 

A.Equal the required clearance with no protection.

B.Equals the reduced clearance permitted in accordance with the preceding clearance chart.

C.The protection applied to the construction that covers the combustible material should extend far enough in each direction to make C equal to A.

The vent connector pipe between the furnace and chimney shall be of equal diameter as the flue outlet of the furnace. The vent connector pipe must be made of 24 gauge (or thicker) corrosion-resistant steel. The vent connector pipe should be as short as possible and installed so that it has a continuous rise from the furnace to the chimney. The horizontal length of a connector to a natural draft chimney or vent serving a single appliance shall not be more than 75 percent of the height of the vertical portion of the chimney or vent above the connector. Elbows should be minimized and the pipe should be joined with metal screws and supported by straps. All horizontal runs of vent connector pipe should be pitched upward a minimum of ¼ inch per foot of run. A thimble should be used to connect the vent connector pipe to the chimney so the pipe may be readily removed in case of inspection or replacement. See Fig. 6 on preceding page.

B. VENTING:

9

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Image 12
Thermo Products OL6FA072DV5(B/R), OL6RA072D48(B/R), OL6FA072D48(B/R), OL6RA072DV5(B/R), OL6RX072DV5(R) B. Venting