Section SPS 371.21 - General installation requirements(1) ACCESS, LOCATION AND CLEARANCES. (a)Access. Components shall be accessible for required routine maintenance without trespassing on adjoining property or disassembling any major portion of the solar energy system, building or dwelling.(b)Location.1. Components within 10 feet horizontally of a chimney or vent shall be at least 2 feet below the top of the chimney or vent.2. The location of components may not interfere with the operation of required doors, windows or other building components. Note: Components may be subject to local zoning requirements.
(c)Clearances.1. Combustible materials may not be exposed to components having maximum operating temperatures that can cause ignition. Clearances to combustible materials specified in the component listing or by the component manufacturer shall be maintained.2. Clearance between combustible materials and unlisted components shall be maintained in accordance with Table 371.21-A. Table 371.21-A.
Clearance Between Combustible Materials and Unlisted Components
Maximum Sustained Surface Temperature | 1Required Clearance (inches) |
200ºF or less | 0 |
201ºF to 250ºF | 1 |
251ºF to 500ºF | 6 |
Over 500ºF | Approval required |
1If approved insulation protects the component, the required clearance may be reduced by 50%.
(2)MATERIAL TESTS AND STANDARDS. The installation of, as well as all materials used in the construction of, solar energy systems shall meet the applicable requirements specified in chs. SPS 320 to 325, 361 to 366, and 381 to 387 and this chapter. Where different chapters specify different requirements, the most restrictive material test and installation standard shall apply.(3)INSULATION. (a)General. Insulation of piping, ducts and thermal storage containers shall be of a type satisfactory for its intended purpose and installed in accordance with recognized standards and practices.1. `Flame spread rating.' The flame spread rating for all insulation materials may not exceed the following values: Plastic foam: 75 Other insulation materials: 1502. `Compressive loads.' Insulation shall be protected against compressive loads from pipe and duct supports and storage tanks.3. `Exterior insulation.' Exterior insulation shall be capable of withstanding moisture, ultraviolet radiation, and environmental exposure.(b)Piping. Pipes of nominal size of one and one-half inch or larger shall be insulated to a thermal resistance value of R-4 or greater. All other piping in the solar energy system shall be insulated to a thermal resistance value of R-3 or greater. A vapor barrier, if installed, shall be located on the warm side of the insulation.(c)Ducts. Ductwork located in unheated spaces shall be insulated to a thermal resistance value of R-11 or greater, where space permits. Ductwork in heated spaces shall be insulated to a thermal resistance value of R-3 or greater. A vapor barrier, if installed, shall be located on the warm side of the insulation.(d)Thermal storage.1. `Thermal storage - liquid systems.' Thermal storage for liquid systems located in unheated spaces shall be insulated to an overall thermal resistance value of R-16 or greater. Thermal storage for liquid systems installed in heated spaces shall be insulated to an overall thermal resistance value of R-11 or greater.2. `Thermal storage - air systems.' Thermal storage for air systems located in unheated spaces shall be insulated to an overall thermal resistance value of R-38 or greater. Thermal storage for air systems installed in heated spaces shall be insulated to an overall thermal resistance value of R-11 or greater.(4)PROTECTION. (a)Protection against vermin. All penetrations of the building or dwelling by components shall be properly sealed with noncombustible material to prevent the entrance of vermin.(b)Protection against vehicular or pedestrian traffic. Components exposed to vehicular or pedestrian traffic shall be protected against impact damage.(c)Protection against water penetration. All penetrations by components into a building or dwelling from the outside shall be properly sealed and waterproofed with approved materials to prevent leaks, insects and drafts from entering the building or dwelling. All penetrations shall be made using weatherproof devices which will allow for expansions and contractions.(d)Protection against decay and termites. Wood used in the construction of the collector or mounting, and exposed to outdoor conditions shall be pressure-treated with preservative or shall be a naturally durable, decay resistant species of lumber and shall be protected against termites.(e)Protection from heated components. Components which are maintained at temperatures above 170° F shall be protected from human contact. The protections may be in the form of insulation, metal or plastic guards.(5)SMOKE DETECTORS. All dwellings that contain air systems with wood-frame collectors shall be provided with smoke detectors as specified in s. SPS 321.09.(6)FIRE PROTECTION. The design and installation of the solar energy system and components shall provide a level of fire safety consistent with chs. SPS 320 to 325 for one- and 2-family dwellings, or chs. SPS 361 to 366 for commercial buildings. (a)Vents, pipes and ducts.1. `Existing buildings.' An existing building's vents, pipes, and ducts, installed for the operation of the solar energy system, shall comply with chs. SPS 361 to 366.2. `Existing dwellings.' Existing dwellings shall be provided with draftstopping at openings around vents, pipes and ducts installed for the operation of the solar energy system. Draftstopping materials may not be less than 1/2 -inch gypsumboard, 3/8 -inch plywood, mineral-based insulation or other approved materials.(b)Collectors. A collector intended for installation integral with or forming a part of the building or dwelling roof structure and its associated roof covering material, may not reduce or impair the fire resistance of the designated roof covering material.(7)LOADS. The structural design of the solar energy system, including connections and supporting structural elements, shall be based on loads anticipated during the design life of the solar energy system. Roof loading due to the following loading effects shall be included in the design of all structural elements influenced by these loads:(a)Dead loads.1. `Collector.' The collector and supporting structure, including building components, shall be designed and constructed to support the weight of the collector, other components and heat transfer fluids.2. `Thermal storage.' The thermal storage and supporting structure shall be designed and constructed to support the weight of the storage container, components, heat transfer fluids and storage medium.(b)Live loads.1. `Use.' Surfaces that must support maintenance personnel shall resist a load of 250 pounds distributed over a 4-inch square area.2. `Wind, snow and seismic.' The collector, including any mounting hardware and building components, shall be designed and constructed to resist the wind and snow loads specified in chs. SPS 320 to 325 for one- and 2-family dwellings, or the wind, snow and seismic loads specified in chs. SPS 361 to 366 for commercial buildings. See Image
Wis. Admin. Code Department of Safety and Professional Services SPS 371.21
Cr. Register, June, 1986, No. 366, eff. 7-1-86; CR 01-139: am. (2), (5), (6) (intro.), r. and recr. (7) (b) 2., r. (7) (b) 3. Register June 2002 No. 558, eff. 7-1-02; correction in (6) (a) 1. made under s. 13.93(2m) (b) 7, Stats., Register June 2002 No. 558; correction in (1) (c) 2., (2), (5), (6) (intro.), (a) 1., (7) (b) 2. made under s. 13.92(4) (b) 7, Stats ., Register December 2011 No. 672.