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Solar Thermal Systems (18-28-1501 et seq.)

Municipal Code of Chicago tit. 18, ch. 18-28, art. XV
in effect

Municipal Code of Chicago § 18-28-1501.1 Scope.

18-28-1501.1 Scope. This chapter shall govern the construction, installation, alteration and repair of systems, equipment and appliances intended to utilize solar energy for space heating or cooling, domestic hot water heating, swimming pool heating or process heating.

Municipal Code of Chicago § 18-28-1501.2 Potable water supply.

18-28-1501.2 Potable water supply. Potable water systems shall be protected against contamination in accordance with Chapter 18-29, Plumbing Systems.

Municipal Code of Chicago § 18-28-1501.3 Heat exchangers.

18-28-1501.3 Heat exchangers. Heat exchangers used in domestic water-heating systems shall be approved for the intended use. The system shall have adequate protection to ensure that the potability of the water supply and distribution system is properly safeguarded.

Municipal Code of Chicago § 18-28-1501.4 Solar energy equipment and appliances.

18-28-1501.4 Solar energy equipment and appliances. Solar energy equipment and appliances shall conform to the requirements of this chapter and shall be installed in accordance with the manufacturer's installation instructions.

Municipal Code of Chicago § 18-28-1501.5 Ducts.

18-28-1501.5 Ducts. Ducts utilized in solar heating and cooling systems shall be constructed and installed in accordance with Article 6 of this chapter. (Amend Coun. J. 9-14-21, p. 35949, Art. XIV, § 2)

Municipal Code of Chicago § 18-28-1502.2 Controlling condensation.

18-28-1502.2 Controlling condensation. If attics or structural spaces are part of a passive solar system, ventilation of such spaces is not required if other approved means of controlling condensation are provided.

Municipal Code of Chicago § 18-28-1502.3 Roof-mounted collectors.

18-28-1502.3 Roof-mounted collectors. Roof-mounted solar collectors that also serve as a roof covering shall provide moisture and weather protection in a manner consistent with good construction practice. Exception: Plastic solar collector covers shall be limited to those approved by the Building Commissioner.

Municipal Code of Chicago § 18-28-1502.3.1 Collectors mounted above the roof.

18-28-1502.3.1 Collectors mounted above the roof. If mounted on or above the roof covering, the collector array and supporting construction shall be constructed of noncombustible materials or fire-retardant-treated wood.

Municipal Code of Chicago § 18-28-1502.4.1 Pressure and temperature.

18-28-1502.4.1 Pressure and temperature. Solar energy system components that contain pressurized fluids shall be protected against pressures and temperatures that exceed design limitations with a pressure and temperature relief valve. Each section of the system in which excessive pressures are capable of developing shall have a relief device that is located so that no section of the system can be valved off or otherwise isolated from a relief device. Relief valves shall comply with the requirements of Section 18-28-1006.4 and discharge in accordance with Section 18-28-1006.6.

Municipal Code of Chicago § 18-28-1502.4.2 Vacuum.

18-28-1502.4.2 Vacuum. If solar energy system components are subjected to a vacuum while the system is in operation or during shutdown, the components shall be designed to withstand the vacuum or shall be protected from the vacuum with vacuum relief valves.

Municipal Code of Chicago § 18-28-1502.4.3 Protection from freezing.

18-28-1502.4.3 Protection from freezing. System components shall be protected from damage by freezing of heat transfer liquids at the lowest ambient temperatures that will be encountered during the operation of the system.

Municipal Code of Chicago § 18-28-1502.4.4 Expansion tanks.

18-28-1502.4.4 Expansion tanks. Liquid single-phase solar energy systems shall be equipped with expansion tanks sized in accordance with Article 10, Boilers, Water Heaters and Pressure Vessels.

Municipal Code of Chicago § 18-28-1502.6 Filtering.

18-28-1502.6 Filtering. Air transported to occupied spaces through rock or dust-producing materials by means other than natural convection shall be filtered at the outlet from the heat storage system.

Municipal Code of Chicago § 18-28-1503.1 Flash point.

18-28-1503.1 Flash point. The flash point of any heat transfer liquid used in solar system equipment and appliances shall not be less than the highest temperature as determined from the following: 1. Fifty degrees (28°C) above the design maximum operating (flow) temperature of the fluid in the solar system. 2. Two hundred degrees (111°C) below the design maximum non-operating (no-flow) temperature of the fluid attained in the collector, if the collector manifold assembly is located outside of the building and is exposed to the weather, and the relief valves located adjacent to the collector or collector manifold do not discharge directly into the building. 3. The design maximum no-flow temperature in other collector manifold and relief valve configurations.

Municipal Code of Chicago § 18-28-1503.2 Flammable gases and liquids.

18-28-1503.2 Flammable gases and liquids. No flammable liquid or gas shall be used as a heat transfer fluid. The flash point of liquids used in industrial (G1 and G2), Storage (H1 and H2) and Hazardous (Class 1) occupancies shall not be lower unless approved.

Municipal Code of Chicago § 18-28-1504.1 Collectors.

18-28-1504.1 Collectors. Factory-built collectors shall be listed and labeled, and shall bear a label showing the manufacturer's name and address, the collector's model number, the collector's dry weight, the collector's maximum allowable operating and non-operating temperatures and the types of heat transfer fluids that are compatible with the collector. The label shall make it clear that these specifications apply only to the collector.

Municipal Code of Chicago § 18-28-1504.2 Thermal storage units.

18-28-1504.2 Thermal storage units. Pressurized thermal storage units shall be listed and labeled, and shall bear a label showing the manufacturer's name and address, the unit's model number, the unit's serial number, the unit's maximum and minimum allowable operating temperatures, the unit's maximum and minimum allowable operating pressures and the types of heat transfer fluids compatible with the unit. The label shall make it clear that these specifications apply only to the thermal storage unit.
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2689263Fetched: 10/24/2026

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