The required clearance to combustibles for chimney connectors shall be 18 inches. This clearance may be reduced in accordance with Table 323.045-B. The specified protection shall be applied to and cover all combustible material as specified in Figure 323.045-A.
Connectors and chimneys for solid fuel-burning appliances shall be designed, located and installed to permit ready access for internal inspection and cleaning.
The horizontal length shall not exceed 75% of the total vertical height of the entire venting system measured from the appliance outlet.
The connector shall maintain a rise of at least 1/4 inch per foot from the appliance outlet to the chimney inlet.
Connectors shall be securely supported and joints fastened with a minimum of 3 sheet metal screws or rivets.
Appliances used mainly for wood burning shall have the joints assembled so that the crimped end points towards the stove. Appliances burning coal shall have the joints assembled so that the crimped end points away from the appliance.
A connector to a masonry chimney shall extend through the wall to the innerface of the liner but not beyond.
The effective area of the connector shall not be less than the area of the appliance flue collar.
No chimney connectors may pass through any floor, ceiling, window, door or combustible wall nor be concealed in any closet, attic or similar space. A connector may pass through a combustible wall if the connector is guarded at the point of passage by one of the following methods:
Metal ventilated thimble not less than 12 inches larger in diameter than the connector.
All combustible material in the wall is cut away from the connector a sufficient distance to provide the required 18-inch clearance. Any material used to close up such openings shall be noncombustible.
A manual, cast iron damper to control draft shall be provided in the chimney connector. The damper shall not obstruct more than 80% of the connector area. Listed solid-fuel appliances whose listing prohibits the use of manual dampers in the connector shall not require a manual damper to be installed.
CONSTRUCTION USING COMBUSTIBLE MATERIAL
“B" Equals the reduced clearance permitted in accordance with Table 323.045-B. The wall protection should extend far enough in each direction to make `C' equal to `A'.
CONNECTOR CLEARANCES WITH SPECIFIED FORMS OF PROTECTION1,2,3,4
- See PDF for table
SPS 323.045 Note
1 Spacers and ties shall be of noncombustible material.
SPS 323.045 Note
2 All methods of protection require adequate ventilation between protective material and adjacent combustible walls and ceilings.
SPS 323.045 Note
3 Mineral wool batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1550° F.
SPS 323.045 Note
4 If a single wall connector passes through the masonry wall there shall be at least 1/2 inch of open ventilated air space between the connector and the masonry.
(5) Mounting on floors.
Appliances shall be placed on surfaces as described in Table 323.045-C. Solid-fuel-burning appliances listed specifically for installation on a floor constructed of combustible material may be installed in accordance with the terms of the listing and the manufacturer's instructions.
(5m) Mounting on the ground.
Ground-based solid-fuel-burning appliances shall be installed in accordance with the manufacturer's specifications.
Solid-fuel-burning appliances shall be installed with clearances not less than specified in Table 323.045-D, except as provided in pars. (b)
Listed appliances exception.
Listed appliances shall be installed in accordance with the terms of their listing if greater clearances other than those specified by Table 323.045-D are required in accordance with the listing.
Clearance with protection exception.
Solid-fuel-burning appliances may be installed with reduced clearances provided the combustible material is protected as described in Table 323.045-E. The specified protection shall be applied to and cover all combustible material as specified in Figure 323.045-B.
Accessories for solid fuel-burning appliances such as heat exchangers, stove mats, floor pad and protection shields, shall be listed and shall be installed in accordance with the terms of their listing.
(8) Supplemental units.
Supplemental solid-fuel-burning units connected to a furnace shall be connected to the warm air side of the furnace as illustrated in Figures 323.045-C to E, and shall be installed in accordance with all of the following:
(a) Return air duct.
The area of the return air duct shall be at least equal to the area of the warm air supply duct. The return air duct shall be of the same material as specified for supply air ducts. Return air grilles shall not be located in bathrooms, kitchens, garages, utility spaces or in a confined space defined under s. SPS 323.06
in which a draft diverter or draft regulator is located.
The blower on the furnace shall maintain the manufacturer's specifications for cubic feet per minute air flow and static pressure when the supplemental unit is in operation.
(c) Outside air intake.
The outside air intake shall be connected to the cold air return plenum of the furnace. A volume damper shall be placed in the duct for the fresh air intake.
The thermostat control on the supplemental heating unit shall activate the blower motor at a temperature between 100°
(e) Supplemental units.
Supplemental solid-fuel-burning units shall be installed to maintain a 3-foot clearance between the unit and the furnace or shall be installed in accordance with the listings of both the supplemental unit and the furnace if such an installation is specifically covered by the listings.
- See PDF for table
STANDARD CLEARANCES FOR
PROTECTION OF COMBUSTIBLE WALLS
(9) Supply ducts.
Supply ducts connected to solid-fuel-burning appliances shall have the following minimum clearances to combustibles:
(a) Horizontal ducts.
The clearance from combustibles for horizontal ducts shall be as specified in Table 323.045-F.
SPS 323.045 Note
1 Clearance can be reduced in accordance with Table 323.045-B
Air shall travel 6 feet and change directions equivalent to one 90°
turn before entering an enclosure of combustible material.
Ducts shall have 3/16 inch clearance between the duct and any combustible material.
(10) Combination appliances.
Appliances capable of burning multi-types of fuel shall be listed and installed in accordance with their listing.
SPS 323.045 History
Cr. Register, February, 1985, No. 350
, eff. 3-1-85; am. (1), (3) (a) 1., (4) (b), (5), (6) (a), (6) (b) 2., (8) (intro.) and (9) (a), renum. Tables 23.045-B to E to be Tables 23.045-C, D, B and F and am. B and F, Figures 23.045-C to E renum. from Figures 23.01-A to C, cr. (2) (c), (3) (b) to (e) and (8) (e), Table 23.045-E and Figure 23.045-B, r. and recr. (6) (b) 1., Register, January, 1989, No. 397
, eff. 2-1-89; am. (1), (2) (b) (intro.), (3) (a) 1., (8) (a) and Table A, cr. (2) (b) 4., r. and recr. Table C, Register, March, 1992, No. 435
, eff. 4-1-92;
am. Table C, Register, November, 1995, No. 479
, eff. 12-1-95; r. (2) (b) and renum. and am. (2) (c) to be (2) (b), Register, March, 2001, No. 543
, eff. 4-1-01; CR 08-043
: am. (2) (b) Register March 2009 No. 639
, eff. 4-1-09; correction in (3) (a) 2., (4) (a), (b), (5) (a), (6) (a) (intro.), 1., 2., (8) (intro.), (a), (9) (a), Figure 323.045-A, Table 323.045-E, 323.045-F made under s. 13.92 (4) (b) 7.
, Stats., Register December 2011 No. 672
; CR 15-041: renum. (5) (a) to (5), cr. (5m), cr. (6) (a) (title), renum. (6) (a) (intro.) to (a) and am. (intro.), am. (8) (intro.) Register December 2015 No. 720, eff. 1-1-16.
SPS 323.05 Safety controls.
High limit, maximum outlet air temperature and similar safety controls shall be provided on heating equipment.
SPS 323.05 History
Cr. Register, November, 1979, No. 287
, eff. 6-1-80.
Naturally vented appliances and other appliances that require air for combustion and dilution of flue gases to be taken from within the building shall comply with this section.
Appliances that are provided with a direct supply of outside air for combustion in accordance with the manufacturer's installation instructions and listing are not required to comply with this section.
Where the appliance listing and manufacturer's instructions are more stringent than the provisions of this section, the listing and manufacturer's instructions apply.
Listed fireplace stoves are not required to comply with this section if permitted in the manufacturer's instructions.
Listed factory-built fireplaces shall comply with the manufacturer's recommendations and shall conform with the requirements of s. SPS 321.32
(2) Methods for providing air.
Air for combustion and dilution shall be provided in accordance with one of the following:
If the vapor retarder is not continuous on walls and ceilings exposed to the outside atmosphere as allowed by s. SPS 322.38
, air may be provided from inside the building in accordance with sub. (3)
Air may be provided from outside the building in accordance with sub. (4)
The appliance may be installed in accordance with its listing and manufacturer's instructions. Where all walls and ceilings exposed to the outside atmosphere are provided with a continuous vapor retarder, any requirements for unusually tight construction shall be met.
An engineered system providing an adequate supply of air for combustion ventilation and dilution of flue gases may be installed if approved by the department.
The equipment shall be located in a space with a volume not less than 50 cubic feet per 1000 Btu/h of the combined input rating of all fuel-burning appliances drawing combustion and dilution air from that space.
The space may be made up of more than one room if the rooms are connected through doorways without doors or connected through sets of openings described in par. (b)
When needed to connect rooms, two openings shall be provided, one within one foot of the ceiling of the room and one within one foot of the floor.
The net free area of each opening shall be a minimum of one square inch per 1000 Btu/h of combined input rating of the fuel burning appliances drawing combustion and dilution air from the communicating rooms, but shall be not less than 100 square inches.
When air for combustion and dilution is provided from outside the building, as allowed under sub. (2) (b)
, one of the methods specified in pars. (b)
shall be used.
Openings may be provided to connect rooms containing appliances to the outdoors.
Two openings shall be provided, one within one foot of the ceiling of the room and one within one foot of the floor.
Openings may connect directly to the outdoors or to the outdoors through a horizontal or vertical duct.