Wisconsin Legislature: SPS 327.44(2)(a)

a. The net free area of the opening shall be a minimum of one square inch per 3000 Btu/h of combined input rating of the fuel-burning appliances drawing combustion and dilution air from the room, and not less than the combined cross-sectional flow areas of the appliance flue collars or draft hood outlets.

b. The cross-sectional area of the duct shall be equal to or greater than the required size of the opening.

4. The appliances shall have a minimum clearance to the surfaces of the room of one inch at the sides and back of the appliance and 6 inches at the front of the appliance.

(d)

1. A combination of openings to the outside and openings to other rooms may be used in accordance with this paragraph.

a. One opening shall connect directly to the outdoors, connect to the outdoors through a horizontal duct, or connect to the outdoors through a vertical duct.

b. The net free area of the openings shall be calculated in accordance with sub. (5).

c. The net free area of the opening shall be a minimum of one square inch per 5000 Btu/h of combined input rating of the fuel burning appliances drawing combustion and dilution air from the room.

d. The cross-sectional area of a duct, if used, shall be equal to or greater than the required size of the opening.

a. 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 installed in that space.

b. The space may be made up of more than one room if the rooms are connected through openings without doors or connected through sets of openings described in subd. 4.

a. 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.

b. The net free area of openings shall be calculated in accordance with sub. (5).

c. 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.

(5) Net free area calculation.

(a) The required size of openings for combustion and dilution air shall be based on the net free area of each opening.

(b) The net free area of an opening shall be that specified by the manufacturer of the opening covering or by a source approved by the department.

(c) In the absence of such information, openings covered with metal louvers shall be deemed to have a net free area of 75 percent of the area of the opening, and openings covered with wood louvers shall be deemed to have a net free area of 25 percent of the area of the opening.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.42 Mechanical draft systems. Where a mechanical draft system, such as a fan is used, provision shall be made to prevent the flow of gas to the main burners when the draft system is not performing so as to satisfy the operating requirements of the system for safe performance.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.43 Equipment maintenance information. Required regular maintenance actions for equipment shall be clearly stated and incorporated on a readily accessible label. The label may be limited to identifying, by title or publication number, the operation and maintenance manual for that particular model and type of equipment. Maintenance instructions shall be furnished for equipment which requires preventive maintenance for efficient operation. Manufacturer’s manuals for all installed heating and cooling equipment and service water heating equipment shall be provided.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.44 Ductwork.

(1) Duct use. Ducts designed for the transmission of air shall be used for no other purpose.

(2) Interior ducts. All interior ducts shall be constructed in accordance with the following:

(a) Supply and return air ducts. Supply and return air ducts shall comply with this paragraph except that ducts attached to appliances may be constructed of materials specified in the appliance listing.

1. Kitchen exhaust ducts and ducts for air exceeding 250 degrees Fahrenheit shall be constructed of sheet metal or lined with sheet metal or constructed of other noncombustible noncorrugated materials.

2. Ducts connected to furnaces shall be constructed of sheet metal for at least 6 feet from the furnace.

3. Spaces formed by unlined wood joists, studs or wood I-joists with solid webs may be used as return air ducts. Spaces used as return air ducts shall be cut off from all remaining unused portions of the space by tight-fitting stops of sheet metal or of wood joist material. Bridging shall be removed from the joist space.

(b) Under-floor plenums. An under-floor space may be used as a plenum in a camping unit in accordance with this section.

1. Except for the floor immediately above the under-floor plenum, supply ducts shall be provided extending from the plenum to registers or other floor levels.

2. The under-floor spaces shall not be used for storage, shall be cleaned of all loose scrap material and shall be tightly and substantially enclosed.

3. The enclosing material of the under-floor space, including the side wall insulation and vapor barriers, shall not be more flammable than one-inch wood boards.

4. Access shall be through an opening in the floor which shall be 18 inches by 24 inches.

5. The furnace supplying warm air to the under-floor space shall be equipped with an automatic control which will start the air circulating fan when the air in the furnace bonnet reaches a temperature not higher than 150 degrees Fahrenheit. The control shall be one that cannot be set higher than 150 degrees Fahrenheit.

6. The furnace supplying warm air to the under-floor space shall be equipped with an approved temperature limit control that will limit outlet air temperature to 200 degrees Fahrenheit.

7. A noncombustible receptacle shall be placed below each floor opening into the air chamber. The receptacle shall be securely suspended from the floor members and shall be not more than 18 inches below the floor opening. The area of the receptacle shall extend 3 inches beyond the opening on all sides. The perimeter of the receptacle shall have a vertical lip at least one inch high at the open sides if it is at the level of the bottom of the joist, or 3 inches high if the receptacle is suspended.

8. Floor registers shall be designed for easy removal to permit access for cleaning the receptacles.

9. Exterior walls and interior stud partitions shall be firestopped at the floor.

10. Each wall register shall be connected to the air chamber by a register box or boot.

11. A duct conforming to par. (a) shall extend from the furnace supply outlet at least 6 inches below combustible framing.

12. The entire ground surface and enclosing exterior walls of the under-floor space shall be covered with a vapor barrier having a vapor permeability rating of one perm or less and a flame spread rating of 200 or less.

13. Fuel gas lines may not be located within the under-floor space.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.45 Dampers, registers, and grilles.

(1) Volume and backdraft dampers.

(a) Volume duct dampers shall be provided to permit balancing of the system.

(b) Volume dampers shall be provided with access.

Note: Acceptable means of access include a manufactured access panel, an air grille used as a cover, a plastic ceiling cap, or a damper accessible through an air diffuser or grille.

(2) Air registers and grilles.

(a) Supply air registers. All supply air outlets shall be provided with registers or devices which will provide a uniform distribution of air.

(b) Return air grilles. Return air grilles shall not be located in bathrooms, kitchens, utility spaces, or a confined space in which a draft diverter or draft regulator is located. All other habitable spaces shall have permanent openings to a return air grille equal in area to the supply outlet serving those areas. At least one return air opening shall be provided for each floor.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.46 Piping.

(1) Pipe sizes and arrangement. All steam and hot water supply and return piping, air-line piping and auxiliary equipment shall be of appropriate sizes, elevations and arrangements to accomplish the calculated results without stress or other detriment.

Note: The sizes of pipe to be used for mains and risers may be selected from the ASHRAE Guide and Data Book, published by the American Society of Heating, Refrigerating and Air Conditioning Engineers; or the manuals published by the Institute of Boiler and Radiator Manufacturers or the Mechanical Contractors Association of America.

(2) Expansion and contraction. The piping for the heating system shall be equipped with anchors, expansion swings, or joints, supports and similar devices to relieve stress and strain caused by temperature change of the pipe material.

(3) Pipe insulation. Unguarded steam, hot water supply and return piping shall be covered with insulating material where the pipes pass through occupied areas and the surface temperature exceeds 180 degrees Fahrenheit.

(4) Steam and hot water pipes. No pipe carrying hot water or steam at a surface temperature exceeding 250 degrees Fahrenheit shall be placed within one inch of any combustible material, pass through a combustible floor, ceiling, or partition unless the pipe is protected by a metal sleeve one inch larger in diameter than the pipe or with approved pipe covering.

(5) Balancing. Balancing cocks shall be provided in each circuit of a hot water distribution system.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.47 Venting system location. A venting system shall terminate at least 3 feet above any forced air inlet located within 10 feet horizontally. This provision does not apply to the combustion air intake of a direct-vent appliance.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.48 Multiple appliance venting. Two or more listed gas-or liquid-fueled appliances may be connected to a common gravity-type flue provided the appliances are equipped with listed primary safety controls and listed shutoff devices and comply with the following requirements:

(1) The appliances shall be located in the same story, except for engineered venting systems.

(2) The appliances shall be joined at a manifold or Y-type fitting as close to the chimney as possible, unless the connector from each appliance enters a separate chimney inlet and the inlets are offset at least 12 inches vertically or the separate inlets occur at right angles to each other.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

SPS 327.49 Fuel storage.

(1) LP gas storage tanks.

(a) All LP gas storage tanks shall be constructed, installed, and maintained to conform with the applicable sections of ch. SPS 340.

(b) LP gas tanks may not be located inside camping units.

(2) Oil storage tanks.

(a) The total oil storage capacity inside any camping unit shall be limited to 550 gallons in one tank, or not more than 275 gallons in each of 2 tanks cross-connected to a single burner.

(b) Oil storage tanks on the inside of any camping unit shall be located at the same level as the burner it serves.

Note: Except as provided in pars. (a) and (b), the installation of oil storage tanks is regulated under ch. ATCP 93, Flammable, Combustible, and Hazardous Liquids.

(3) Gas piping systems. Gas piping systems, extending from the point of delivery to the connection with each gas-fired appliance or device, shall be installed to conform with NFPA 54, National Fuel Gas Code.

(4) Shutoff and control devices.

(a) Any oil-fired appliance or device connected to a fuel piping system shall have an accessible, approved manual shutoff valve installed upstream of any connector.

(b) Automatic gas-burning heating appliances shall be equipped with listed devices which will shut off the gas to the pilot light and main burner or burners in the event of pilot failure.

(c) Liquid fuel-burning appliances shall be equipped with primary safety controls which will shut off the flow of fuel to the burner or burners in the event of ignition failure.

History: EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4-1-18.

Subchapter IV — Electrical Standards

SPS 327.50 Electrical standards.

(1) All electrical wiring, installations, equipment and materials used in the construction of camping units shall comply with the requirements of the Wisconsin Administrative Electrical Code, Vol. 2., ch. SPS 316, except as provided in this section.