Every week we will be including additional questions and informal UPC and UMC interpretations
- UMC 2021 Section 609.1 requires air moving systems in excess of 2,000 CFM to be installed with automatic shutoff.
It further describes the method of shutdown to be accomplished by ....installation in the main supply air duct served by such equipment.
If I have a 400,000 sq. ft. warehouse with (9) 26,000+ CFM exhaust fans with make up air provided by louvers near the door bays.
Would the exhaust fans be considered a component of an "air moving system" and require the automatic shutoff be accomplished by an alternate means of the supply air duct location (total coverage smoke-detection, for example)?
- No, as defined in Chapter 2 of the 2021 Uniform Mechanical Code, air-moving systems pertain to air-handling units. An air-handing unit is defined as a blower or fan used for the purpose of distributing supply air to a room, space, or area. An exhaust system does not have the same requirements as an air-moving system. Section 608.1 applies specifically to air supply moving systems and not exhaust systems.
However the Authority Having Jurisdiction would determine the occupancy classification of the warehouse. Its use and occupancy would have a direct bearing on whether smoke detection or fire separation is required. Smoke detection required under this type of occupancy maybe required to be interlocked to the fan power source to provide shutdown upon detection of smoke.
- Is it permitted to stub out a gas line for a BBQ to be located under a covered (but not enclosed) patio?
- Yes, as long as the gas pipe is above ground. Section 1211.9 (2009), 1210.9 (2012/ 2015), 1210.7 (2018), 1210.8 (2021) lists several requirements for gas outlets.
- Does the Uniform Mechanical Code allow you to provide cooling to a refrigeration machinery room in a climate where the outside air may be 105°F or higher?
- Yes. The intent of the code is to limit the temperature rise within the machinery room to 104°F and does not specifically preclude the use of a cooling unit to satisfy the requirement.
- What are the codes and regulations relating to the use of kitchen-generated gray water?
- The provisions for the installation of Gray Water Systems are found in Chapter 15 (2015/2018/2021), Chapter 16 (2009/2012) Alternate Water Sources For Non Potable Applications. Kitchen sink waste is not allowed in a Gray Water System. The definition of Gray Water in Chapter 2 Definitions is untreated wastewater that has not come into contact with toilet waste, kitchen sink waste, dishwater waste or similarly contaminated sources. Gray water includes wastewater from bathtubs, showers, lavatories, cloth washers and laundry tubs.
- Is a low-pressure gas test limited to a 10 pound test using a 20 pound gauge, or would a 26 pound test using a 52 pound gauge comply with Uniform Plumbing Code requirements?
- A required 10 pound test mandates a gauge with minimum incrementations of 1/10 pound, while restricting the pressure range of the gauge to not greater than twice the pressure applied. Therefore, a required 10 pound test may be performed at any pressure (in excess of the minimum required pressure), provided the gauge incrementations do not exceed 1/10 pound and the test pressure applied is at least one-half of the pressure range of the gauge.
- Does the scope of UMC Chapter 11 include cooling systems used for human comfort? For example would a chilled water air handler, refrigeration system, split system DX fan coil or heat pump apply?
- Yes, comfort air is within the scope of Chapter 11 (2003/2006/2009/2012/2015/2018/2021).
- Is an anodeless type gas transition riser the only type that can be used for installation of plastic gas piping? Comment: Transition gas riser companies make a compression type gas riser that is used for connecting plastic underground and then terminating to the surface. Are these acceptable to the UPC?
- Anodeless risers shall be permitted in accordance with section 1211.1.7(2003/2006/2009) 1210.1.7(2012) 1208.5.4.2 (2015) 1208.6.7 (2018/2021) provided they meet all applicable listing and product approval criteria. Specifically, connections that transition between metallic & plastic piping shall conform to ASTM D2513, ASTM F1973 or ASTM 2509. If the riser is appropriately listed with compliant connections it may be approved.
- In Chapter 4 of the UMC, is there a requirement for the location of outside or ventilation intake?
- No, although there are sections in the code that refer to the termination of other items to an intake. For example, Section 504.5 (2003/2006/2009/2012/2015/2018/2021) for environmental air duct limitation, Sections 510.8.2.1 and 510.8.3 (2003/2006/2009/2012/2015/2018/2021) for commercial kitchen grease duct exhaust, and Sections 802.6 and 802.8 (2003/2006/2009/2012/2015/2018/2021) for gas vent limitations.
- Is a right/left nipple/coupling allowed to be concealed in the UPC?
- No, Section 1211.3.2 of the UPC (starting in 2009) specifically prohibits the use of right and left couplings in concealed locations. When NFPA 54 was inserted into the code in 2003, it changed a number of things we had always done under the UPC, the use of right and left hand couplings being one of them. The 2012/2015/2018/2021 UPC Section 1210.3.1 has been revised to now include the use of right/left nipple/couplings and to no longer permit the use of ground joint unions in concealed spaces.
- Is the removal of a door from a mechanical room in a single family dwelling acceptable in accordance with Section 701.5 of the 2021 UMC, to achieve proper combustion air requirements for combining spaces on the same story?
- No. Simply removing the door is not adequate. The intent of the code is to provide a permanent opening when combining communicating spaces. In addition to removing the door, the casing and door hardware would also need to be removed and the opening should be finished to provide a permanent opening so that the door cannot be readily installed. If the door to the mechanical room is in a bedroom or bathroom the door cannot be removed and combustion air shall be provided from outdoors as required in Section 904.1 of the UMC (2003/2006/2009/2012/2015/2018/2021).
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