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Uniform Codes Questions & Answers
Uniform Codes Questions & Answers 

Every week we will be including additional questions and informal UPC and UMC interpretations:

The ceiling space in a nonresidential building is used as a return air plenum. It has exposed wood framing members. Although it is combustible material and cannot meet flame and smoke requirements, the space is protected with a metallic fire sprinkler system with sprinklers in the plenum. It also has smoke detectors in the plenum. Is this an allowable installation per the code?

No. Section 602.2 clearly states that material exposed within ducts or plenums shall meet minimum flame-spread index and smoke-developed rating requirements. There are no exceptions that would allow exposed wood within the plenum by adding a fire sprinkler system or smoke detectors.

Is the color coding that is required by Section 601.2 (2330/2006/2009/2012) 601.3 (2015) for potable and nonpotable water systems to be applied by the manufacturer or in the field by the installer?

The identification that is required by Section 301.1.2 (2003/2006/2009) 301.1.1 (2012), 301.2.1 (2015) is applied by the manufacturer. The identification that is required by Section 601.2 (2003/2006/2009/2012) 601.3 (2015)is applied by the installer.

Is Manual D the only approved and authorized method of sizing ductwork per the code?

No. Manual D is not the only approved method of sizing ductwork. ACCA Manual Q may be used for commercial applications. In addition, Section 601.2 states that other approved methods may be used. The Authority Having Jurisdiction would have to determine if the alternate method of sizing would be equivalent to the provisions set forth in the UMC.

Could the drain from a water-tight pan that is required under a water heater be discharged to a tailpiece of a lavatory or to an approved accessible inlet on a bathtub overflow as provided in Section 807.2 (2003/2006/2009/2012) 814.6 (2015) for condensate waste from air conditioning coils?

No. The intent of the Code is to protect the structure from damage and alert the occupant that a leak has occurred. Terminating the drainpipe into a physical connection defeats this objective. Therefore, it is necessary that the termination be at a point which is readily observable.

Do receivers and accumulators have to be located in a refrigeration machinery room for a refrigeration system using ammonia as the refrigerant where the system contains 35 pounds or more of refrigerant?

Yes. Receivers and accumulators for ammonia systems are considered to be part of the refrigeration system and should be placed in a refrigeration machinery room. The condition that triggers this requirement is the amount of refrigerant in pounds per 1,000 cubic feet of space as outlined in Table 11-1 (T1102.2 (2012)).

What is the building owner required to do by the UPC, if anything, with regard to upgrading his facility when a new tenant plans to occupy a space or floor in an existing building?

Plumbing fixtures shall be provided for the type of building occupancy and in the minimum number shown in Table 4-1 (2003/2006/2009). Table 422.1 (2012/2015) The final judgment in such matters is within the purview of the Authority Having Jurisdiction, with rights of appeal when agreement cannot be reached.

1. Would UMC section 609.0 require a smoke detector shutdown for each air handling unit or equipment with less than 2,000 cubic feet per minute where a number of individual systems less than 2,000 cubic feet per minute that do not intermix airflow or use common supply or return are present in a single building (i.e., 3 fan coil units each at 1,200 cubic feet per minute in separate areas of a building with aggregate total of 3,600 cubic feet per minute for the total building)? 2. Is this an aggregate total for the entire building that would then require a smoke detector shutdown for all air moving supply equipment (i.e., individual 500 cubic feet per minute fan coil units throughout a building with, say 8,000 cubic feet per minute supply air total)?

1. No. Section 609.0 applies to air-moving systems which are defined as “a system designed to provide heating, cooling or ventilation in which one or more air-handling units are used to supply air to a common space or are drawing air from a common plenum or space.” Since the example of the system you have provided does not intermix or supply and return from a common area, automatic shutoffs are not required. 2. Yes. An aggregate total is used for units that have a common supply or return. If there were several 500 cubic feet per minute units that shared a common supply and return that exceeded 2,000 cubic feet per minute, then each unit would require an automatic shutoff. The deciding factor is whether or not a common supply or return is used.

This question is regarding the location of a L.P.G. water heater in a laundry room which constitutes a confined space. The laundry room has two doors, one into the hall, and the other door into the bathroom. The only means of access into the bedroom is through the laundry room. Would this installation of a gas fired water heater in the laundry room be allowed by Section 505.1 (2003/2006/2009) 504.1 (2012/2015)?

No. It is not acceptable to install a water heater in a confined space (see Section 205.0) that opens into a bathroom. The only exception would be a direct vent water heater. Section 505.1 (2003/2006/2009) 504.1 (2012/2015) requires that no water heater which depends on the combustion of fuel shall be installed in a closet or confined space opening into a bath or bedroom.

Does the code require the installation of insulation on refrigerant lines outside of a structure used for condensing units located either at ground level or on the roof?

No. The code does not require insulation on refrigerant lines outside the structure.

When replacing the water distribution system of an existing apartment complex, would it be required to replace the shower valve with pressure balancing tub/shower valves?

Pressure balancing shower valves became a code requirement in the 1997 edition of the UPC. Section 101.5.3 (2009), 101.11.2 (2012), 102.2 (2015) does not require fixtures, such as the shower valves in your question, to the current standards unless the valves are being replaced. Replacement valves would need to meet current codes and standards per sections 418.0 (2009); 408.3 (2012/2015).

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