Section 27-892
§ 27-892 Construction. Vent connectors for conversion burners without
draft hoods, or other gas-fired equipment without draft hoods, shall be
constructed of materials having resistance to corrosion and temperature
not less than that of no. 24 galvanized sheet gauge steel.
(a) Vent connectors used for gas-fired equipment having draft hoods
and for conversion burners having draft hoods, shall be constructed of
type B gas vent material or materials having resistance to corrosion and
temperature not less than that of no. 26 galvanized sheet gauge steel.
(b) The vent connector between the equipment and the vertical gas vent
or chimney shall have the greatest possible initial rise consistent with
the headroom available in the equipment area and with the required
clearance to combustible material. The horizontal run of the vent
connector shall be as short as possible and the equipment shall be
located as near the gas vent or chimney as practicable. The maximum
length of an uninsulated horizontal run of vent connector shall not
exceed seventy-five percent of the height of the gas vent or chimney.
(c) No vent connector shall pass through floor or ceiling
construction.
Section 27-893
§ 27-893 Clearances. (a) Minimum clearance. Minimum clearances at vent
connectors to combustible materials shall not be less than those listed
in table 15-10.
(b) Reduced clearances. These clearances may be reduced when the
combustible construction is protected as provided in table 15-11.
Table 15-10 Vent Connector Clearance for Gas-Fired Equipment
========================================================================
Minimum Distances from Combustible
Materials (in.)
----------------------------------------
Type B Gas Vent Other Than Type
Equipment Material B Materials
------------------------------------------------------------------------
Boiler As required by Std. 6
Warm air furnace As required by Std. 6
Water heater As required by Std. 6
Room heater As required by Std. 6
Floor furnace As required by Std. 6
Conversion burner (with
draft hood) 6 9
Equipment with draft hoods 6 9
Equipment without draft
hoods Not Permitted 18
========================================================================
Table 15-11 Reduced Clearances for Vent Connectors with
Specified Forms of Protection (a)
========================================================================
Reduced Clearances Where the Required
Specified Form of Protection (b) Clearance with No Protection is:
--------------------------------------
18 in. 9 in. 6 in.
------------------------------------------------------------------------
(a) 1/4 in. asbestos millboard
spaced out 1 in. (c) 12 6 3
(b) 28 gauge sheet metal on 1/4 in.
asbestos millboard 12 4 2
(c) 28 gauge sheet metal spaced out
1 in. (c) 9 4 2
(d) 28 gauge sheet metal on 1/8 in.
asbestos millboard spaced out 1
in. (c) 9 4 2
(e) 1 1/2 in. asbestos cement
covering on heating appliance 18 9 6
(f) 1/4 in. asbestos millboard
on 1 in. mineral fiber bats
reinforced with wire mesh or
equivalent 6 4 2
(g) 22 gauge sheet metal on 1 in.
mineral fiber bats reinforced with
wire or equivalent 3 2 2
(h) 1/4 in. asbestos cement board
or 1/4 in. asbestos millboard 18 9 4
(i) 1/4 in. cellular asbestos 18 9 3
====================================================================
Notes:
a. Except for the protection described in (e) above, all clearances
should be measured from the outer surface of the appliance to the
combustible material disregarding any intervening protection applied to
the combustible material.
b. Applied to the combustible material unless otherwise specified and
covering all surfaces within the distance specified as the required
clearance with no protection. Thicknesses are minimum.
c. Spacers shall be on noncombustible material.
Section 27-894
§ 27-894 Thimbles. (a) When passing through combustible constructions,
bent connectors constructed of type B gas vent material shall be
installed so that the clearances required by the standard are
maintained.
(b) Vent connections made of single-wall metal pipe shall not pass
through any combustible walls or partitions unless they are guarded at
the point of passage by ventilated metal thimbles not smaller than the
following:
(1) For equipment conforming to standards -- four inches larger in
diameter than the vent connector.
(2) For equipment having draft hoods -- six inches larger in diameter
than the vent connector.
(3) For equipment without draft hoods -- twelve inches larger in
diameter than the vent connector.
Section 27-895
§ 27-895 Size of connectors. The vent connector shall not be smaller
than the size of the flue collar or the draft hood outlet of the
gas-fired equipment. Where a single item of equipment has more than one
draft hood outlet, the vent connector shall equal the combined area of
the draft hood outlets for which it acts as a common connector to the
gas vent or chimney.
To the extent possible under law, Friends of Devin Balkind for Public Advocate has waived all copyright and related or neighboring rights to New York City Administrative Code. This work is published from: United States.
Special thanks to Benjarmin Kallos and Thom Neale who made this content publicly available as a bulk download.