1. No, this definition is specific to liquids, gases, vapors and steam as applicable to a mechanical system installation. 2. No, unless by design they are incorporated into a boiler system as pertinent to Chapter 10 of the 2024 Uniform Mechanical Code. 3. No, not specifically – they might be integrated into a mechanical system or into other systems, such as medical gas, that are regulated by the Uniform Plumbing Code or NFPA 99.
Section 906.1 of the 2024 Uniform Plumbing Code (UPC) states, “Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than six (6) inches above the roof nor less than one (1) foot from any vertical surface”. Though the 2024 UPC does not define “flashing”, it can best be described as an impervious material that is used in building construction to prevent water from passing into a structure through an exterior penetration. Although flashings for plumbing vents are usually designed for roof penetrations, side wall flashings do exist. Vents penetrating the side wall of a structure, by means of a flashing, would be permitted if installed to the requirements found in Section 906.0.
The requirements of this section of the 2012 Uniform Mechanical Code are mandatory when adopted by the jurisdiction as a sustainable practice in order to meet energy requirements. Some jurisdictions do not adopt this section or other appendices of the code. Section E301.1 would also be applicable as the manufacturer installation and operating instructions would also need to be applied to the installation.
1. The depth is measured from the surface of the ground to the top of the pipe, which would provide the required one foot of earth coverage for the entire pipe, as required by Sections 313.5 and 718.2 of the 2024 Uniform Plumbing Code. 2. It is the opinion of this committee that the clearances would be measured edge to edge.
1. Yes. This exhaust air could be considered as class 4 due to the potential for acid vapor as the lead-acid is corrosive. Hydrogen is flammable, when the hydrogen concentration rises to levels above 4% there is a substantial risk of an explosion. 2. Yes. 3. Section 502.2.2 of the 2024 Uniform Mechanical Code is not the only regulation the termination would need to comply with. Consideration would also need to be given to NFPA 70 section 706.10, with additional reference to the Fire Code and IEEE 1635-2012/ASHRAE 21-2012.
UL 1995 is not acceptable as a more stringent substitute for UL 1812. Section 504.5 of the 2024 Uniform Mechanical Code only states UL 1812. UL Standard 1812 is specifically applicable to ducted heat recovery ventilators, whereas UL Standard 1995 has a much broader application as it references HVAC in general. The criteria of UL 1812 includes construction and performance standards for equipment listed for outdoor-use where UL 1995 does not.
Section 710.7 of the 2024 Uniform Plumbing Code states that the the use of pipe and fittings for gravity waste systems may be used for “fixtures, sumps, receiving tanks, and mechanical waste-lifting devices.
Yes, Electrical Equipment that serves the Chiller and also other Equipment in the building may reside in the same room as the chiller, provided the refrigerant is Group A1. The electrical equipment that serve the chiller room needs to meet section 1108.2 of the 2024 Uniform Mechanical Code. Electrical equipment that is essential for the refrigeration process, maintenance of the equipment, or for the illumination of the room can be placed in the machinery room as long as the electrical equipment complies with the electrical code, whereas electrical equipment that serves solely other parts of a building cannot be placed in a machinery room. As stated in the comment the chiller uses a safe refrigerant classed A-1 and most of the equipment listed serves the refrigeration process in one way or another therefore the Authority Having Jurisdiction deemed them safe and essential to the process, Exclusion would be applied to equipment, piping, ducts, vents, or similar devices that are not essential for the refrigeration process. If it is not essential for the chiller room it clearly states that it shall not be in the chiller room under the provisions of section 11098.1 of the 2024 Uniform Mechanical Code. In describing this specific Refrigeration Machinery Room the equipment serves both the chiller and other equipment in the building. Sections 1107.1.8, 1108.1 and 1108.2 of the 2024 Uniform Mechanical Code state that the machinery rooms with Safety Group A1 or B1 refrigerants are not required to be classified as a Class1, Division1 hazardous location; and when other refrigerants are used, instances the machinery room would be considered either a Class1, Division1 or Class1, Division 2 hazardous location for the fans and associated equipment to operate the emergency purge of the machinery room. The flammability ratings increase in Safety Group A2 and A3, or B2 refrigerants; while both the flammability along with the toxicity increase in the Safety Group B3 refrigerants. The intent of the UMC is to recognize the use of certain refrigerants if properly treated are not necessarily any more dangerous to work in than other locations. In those machinery rooms where other than Safety Group A1 or B1 refrigerants are used, the electrical components of the fans and associated equipment to operate the emergency purge of the machinery room would need to intrinsically safe.
The rate of “free air” flow has to do with the air compressor. There are several ways to measure the capabilities of an air compressor, CFM, SCFM (Standard cubic feet per minute), FAD (Free Air Delivery). CFM is the imperial method of describing the volume flow rate of compressed air. It must be defined further to take account of pressure, temperature and relative humidity. SCFM is the flow in CFM measured at some reference point but converted back to standard air conditions (Standard Reference Atmosphere) 14.7 psia, 60°F. Free Air (Free Air Delivery FAD) is the actual quantity of compressed air converted back to the inlet conditions of the compressor. The units for FAD are CFM in the imperial system and l/min in the SI system. The units are in general measured according the ambient inlet standard conditions. Table 1305.2 requires the Nitrogen flow rate to be based on the free air delivery rating. The other gases in the Table are to be rated by CFM or SCFM. An example of rating a compressor by FAD: As an additional bit of information, nitrogen used in medical settings is more apt to be used for powering pneumatic tools than any therapeutic application.
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