Land Use and Environmental Service Agency (Code Enforcement) NC Mechanical Code 2011

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1 Table of Contents Chapter 1 Administration Chapter 2 Definitions Chapter 3 General Regulations Chapter 4 Ventilation. Chapter 5 Exhaust Systems Chapter 6 Duct Systems Chapter 7 Combustion Air Chapter 8 Chimneys & Vents Chapter 9 Specific Appliances Chapter 10 Boilers, Water Htrs Chapter 11 Refrigeration Chapter 12 Hydronic Piping Chapter 13 Fuel Oil Piping Chapter 14 Solar Systems POLICY OTHER Chapter 1 Administration: 1) (Q) Is it the responsibility of a plans examiner or inspector to inform a designer or contractor of additional requirements of other State agencies or licensing boards? (A) No. It is not the responsibility of the inspector or plans examiner. It shall be the responsibility of the permit holder, design professional, contractor, or occupational license holder to determine whether any additional requirements exist ) (Q) Are explosion proof condensate pumps allowed to be installed on the floor of a garage? (A) Yes. Although a condensate pump, by definition would not be considered an appliance, when used in conjunction with heating and/or air conditioning equipment, it becomes an appurtenance to that appliance. Condensate pumps, used as an appurtenance to a heating/cooling appliance which generates a glow, spark or flame, capable of igniting gasoline vapors and located in a garage shall be installed with burners, burner ignition devices or heating elements and switches at least 18 inches above the floor level. Condensate pumps installed on the floor of the garage must be listed and labeled for installation in a Class 1, Division 2 location, as specified in the NEC, Article 500. An "explosion proof" rating, by itself, does not necessarily mean the equipment will meet this requirement. Listed equipment will be marked to show the class, group (division) and operating temperature or temperature range in which the equipment can be used. The identification numbers are marked on the equipment nameplate. Ref: Chapter 3 General Requirements: 1) (Q) What are the requirements for systems installed in a flood plain? (A) Section Flood hazard: For structures located in flood hazard areas, mechanical systems, equipment and appliances shall be located at or above the design flood elevation. Exception: Mechanical systems, equipment and appliances are permittedto be located below the design flood elevation provided that they are designed andinstalled to prevent water from entering or accumulating within the components and to resist

2 hydrostatic and hydrodynamic loads and stresses, including theeffects of buoyancy, during the occurrence of flooding to the design flood elevationin compliance with the flood-resistant construction requirements of the International Building Code High-velocity wave action. In flood hazard areas subject to high-velocity wave action, mechanical systems and equipment shall not be mounted on or penetrate walls intended to break away under flood loads. See also section for similar the requirements covering the duct system. 2) (Q) Would the discharge line of an appliance condensate pump need to be protected from freezing temperatures? (A) Chapter 307 does not address the protection of condensate discharge lines, installed in areas subject to freezing temperatures, however, we would be remiss if we did not require this protection in areas such as a ventilated attic space. Other areas of concern would be where the line exits the foundation wall. We would recommend that these installations be sloped downward and increasing in pipe size to limit blockages. 3) (Q) What type of access would be required for a boiler installation where the boiler devices may be subject to vandalism or component theft? (A) Chapter 306 covers the typical installation of equipment. Section Would allow us the flexibility to allow alternative access on a case by case basis. 4) Q) Where are the seismic strapping requirements for air conditioners and/or heat pumps in the NC Mechanical Code? (A) Seismic requirements and zone information is in the Building Code as referenced by of the Mechanical Code. 5) (Q Do copper condensate lines or return piping of heating/cooling units that are in direct contact with galvanized sheet metal duct and/or plenum constitute a potential for galvanic action? (A) It is recommended that piping be protected from potential corrosion by protecting or isolating the piping ) (Q) What is the proper way to protect an appliance in a residential garage? (A) From the information we have from DOI and past practice if you pulled a straight edge from the garage door opening to the rear of the opening, if the appliance in question was not in the normal path of the vehicle, then no protection is required. No what if s Ref: ) (Q) A mechanical contractor requested an interpretation as to whether traps were required on the condensate from an evaporator coil and if we knew of any conflicts with the energy code involving cleanout vent/ tees on a blow-through unit discharging into an unconditioned area (attic/crawl space)?

3 (A) The code requires the inspector to rely on the manufacturer s data to determine if a trapped drain is required. If any conflicts with other codes are apparent then the contractor may need to consult with the manufacturer to resolve the problem and inform the inspector of the issues. Ref: Chapter 4 Ventilation: 1) (Q) What is the minimum ventilation required for toilet rooms? (A) Toilet rooms are not considered to be habitable space and so their ventilation requirements would be found in table which would require mechanical exhaust and not natural ventilation. Note: We have allowed natural ventilation in the past and we will begin enforcing the mechanical ventilation requirement on permits obtained after April 1, Chapter 5 Exhaust Systems: 1) (Q) Does Mecklenburg County allow an alternative method for type I hood clearances? (A) Mecklenburg County allows the use of NFPA 96, Chapter based on an interpretation by DOI dated 2/2/ ) (Q) In an automotive repair garage with a vehicle exhaust source capture system per NCMC , is it permitted to have one (1) exhaust capture connection for every two (2) bays or is one connection only allowed per bay? (A) The Mechanical Code is silent on this question, however the code language gives the inference that it requires a singular; a source capture system for each vehicle or service bay. One per bay is required. Ref: ) (Q) Even though the code requirements have been met for the installation of the grease duct the contractor wants to add several more cleanout openings because he also has the maintenance contract on the grease duct system. The duct is only 10 inches by 10 inches and the code access door manufacturer informs him the smallest door approved for grease duct installation per code is 12 inches by 12 inches. Can the contractor make his own door to access the grease duct? (A) Yes. Where the duct is smaller than the 12 by 12 minimum the mechanical contractor may provide cleanouts approved by the mechanical official at least equivalent to the minimum requirements of the code for manufactured access doors. Ref:

4 4) (Q)The Mechanical inspector has turned a residential range exhaust installation down because the contractor has used screws to join the pipe together and then sealed the pipe joints with mastic. The pipe extends up through the roof and is terminated per code. Is this inspector correct? Is this a code violation? (A) The inspector may consider this a code violation; reference is smooth inner walls, however there are minimal code restrictions on residential hood installations. While the code reference says smooth we would accept small screws and mastic to fasten the duct joints together. Ref: ) (Q) A contractor asks the inspector if he can combine the bathroom exhaust with the dryer exhaust to value engineer the job for the owner and appease the Architect who is complaining about all of the exterior wall penetrations disturbing the ambiance of his finished exterior walls. Can the inspector allow this installation? Will a redesign in duct sizing, fittings or joints be required? (A) No. No comingling of the dryer exhaust is allowed by code. Ref: ) (Q) A battery room is installed in an existing multistory building. The designer says it is virtually impossible to run the exhaust duct up to the roof because of the tenants and space in the ceiling above so he wants to run the duct into an area way in the middle of the building that is enclosed on all four sides similar to an interior courtyard in an office building. The only thing located in the area way are 10 compressors for AC to the various building tenants. His problem with running the duct to the area way is that he can only get 3 feet of clearance to terminate the exhaust duct. Can this installation be allowed per Code? (A) No, Ref: sub (1) for conveyance of flammable/explosive vapors. 7) (Q) A UL listed grease duct installation for a type I hood is called for inspection. Duct joints are not welded per code requirements; however, the installation instructions show approved joint connections without welded joints. What would the inspector be required to inspect? How does the inspector look at the installation for code compliance? What tests are required for system approval? (A) Inspection of the manufactured system would have to comply with all standard tests for grease duct required for type I hoods including Any tests specified in the manufacturers literature will also be the responsibility of the field inspector. Ref: ) (Q) Under what conditions can an outdoor grill and hood be installed under a covered porch? (A) The hood would be approved if installed per the manufacturer s installation instructions, including the correct fan, and unit sizing-and it is used in a single family detached dwelling. No townhouse/condo/apartment use would be allowed. Ref: ) (Q) A manufacturer has submitted a dryer booster fan to be used in a residential application

5 per IRC Would the inspector approve the booster fan if the contractor has the letter on site for the inspection? (A) Dryer booster fans are not allowed by the code. There is no code language to allow their use. Ref: ) (Q) A counter mounted, induction type, two burner range with a down draft exhaust filter is installed on a counter top in a restaurant open bar buffet. The appliance is cord and plug connected 208V three phase with two burners. The manufacturer does not think a hood or fire suppression system should be required since the unit will be used for sauté and warming only. Should a hood and fire suppression system be required? (A) Yes. The food is producing grease laden vapors and therefore should have a hood and suppression system installed per code. Ref: Chapter 6 Duct Systems: 1) (Q) What method can be used to protect the opening in a floor/ceiling or roof/ceiling assembly where supply duct from the HVAC unit penetrates the assembly? NOTE: There is not a fire damper currently manufactured that is approved for this application when the multi-story building is classified as an R2 occupancy with type V construction. (A) The current code approval for this application requires a smoke detector to be installed in the same room as the HVAC unit that will shut down the unit if smoke is detected. The smoke detector shall tie in to the smoke detector circuit provided for the apt/condo unit. A static damper is required at the ceiling penetration of the HVAC duct penetrations from the unit. This method of protecting the ceiling penetrations is only approved until a Fire Damper is manufactured that provides adequate protection for the openings. 2) (Q) What are the minimum requirements for plenum rated materials within an open air plenum space? (A) Not required. See plenum definition. Open air returns are typically in habitable areas and do not have to conform to the material requirements of enclosed plenums. Example: Home Depot. Ref: Chapter 2 plenum definition. & ) (Q) Unlisted duct tape has been installed on the metal to metal and flex to metal airduct joints of a furnace installation in a single-family dwelling. Is it required that the unlisted duct tape be removed before installing the approved tape or mastic? (A) No, approved tape may be installed over unlisted duct tape unless the listing, labeling or manufacturer s instructions supersede the allowance of such material. Ref: ) (Q) What is considered proper access for smoke/fire dampers? (A) states that the damper must be accessible for removal/maintenance. 5) (Q) Are fire dampers, smoke dampers, or combination dampers required in walls that separate a garage from the residential living space in a single family dwelling?

6 (A) The code has no provisions for a fire damper of any type to be required in this residential installation ) (Q) Are longitudinal seams required to be sealed in a duct used to exhaust a bath fan? (A) Yes. Our policy has always been to seal the seams in a longitudinal duct run in a residential application to prevent any duct leakage on the ceiling. Recent DOI interpretations of the 2012 code MC Section back the department position to seal the exhaust duct. The 2009 code vaguely describes contamination prevention in but exempts one and two family dwellings. Ref; ) (Q) A listed and labeled product (return air grill) is being installed in a panned 2 by 4 wall stud cavity. A return air grill is being installed in the wall cavity at a depth of 1 inch leaving only 2 inches between the return collar and the filter. Is this installation allowed by Code? (A) The inspector must look at the surface area to determine if this installation will meet code. Ref: 602.3, ) (Q) Charlotte Pipe has a new CPVC pipe called ChemDrain with a Zero flame spread rating and a smoke developed rating of between 8 and 22 based on ULC S Can we allow this new pipe in return air plenums? (A) Yes. As long as it is tested and approved for at least smoke and flame spread rating we would allow the product in return air plenums. Ref: ) (Q) A residential 3 story apartment building has louvered doors on a closet which is used for the return air to the AC unit. The closet doors are made out of wood. (a)is the closet allowed to be used as part of the return? (b)does the closet meet minimum requirements for a return air plenum? (c) Could the doors be used in a commercial office space? (A) (a) Yes. (b) Yes. (c) Plenums in dwellings are not required to meet the code requirements for non-combustible materials within plenum spaces. Materials in plenums for all other occupancies shall be non-combustible or meet requirements. Ref; 602.2, , exception # 3. 10) (Q) What are the minimum requirements for access to a fire damper located inside a duct when the ductwork is located behind a sheet rock wall? Would the requirements be the same for commercial and residential construction? (A) The access shall be by an approved means large enough to permit inspection and maintenance of the damper and its operating parts. The access opening shall not affect the integrity of fireresistance rated assemblies. Access doors in ducts shall be tight fitting and suitable for the required duct construction. Ref: [B]

7 Chapter 9 Specific Appliances, Fireplaces and Solid Fuel-Burning Equipment: 1) (Q) What is the minimum clearance of a microwave oven hung under an existing stove cook top? The manufacturer s instructions require a 24 inch clearance. This clearance will work but just barely because of the existing cabinet height. The house is in a historic district and the governing board does not allow removal or alteration of existing cabinets in the district. Can the inspector allow the manufacturers approved clearance? (A) Yes. Install the equipment per manufacturer s clearances. Ref: Chapter 10 Boilers, Water Heaters and Pressure Vessels: (1) (Q) An out of state jurisdiction ask the department about the enforcement of ASME Boiler and Pressure vessel regulation enforcement for the state of North Carolina. Who enforces regulations for UNFIRED pressure vessels for (1) Newly installed pressure vessels to comply with ASME Boiler and Pressure Vessel Code, (2) Repairs and alterations for existing boilers, and (3) Other regulations or codes that also apply to boilers? (A) The Department of Labor Boiler and Pressure Vessel division has primary responsibility over boiler inspections, however there is a list of exempt boilers. The exempt boilers are governed by the North Carolina Mechanical and Fuel Gas codes as enforced by the Office of the State Fire Marshall through the Department of Insurance. Ref: Ch. 10 and NCGS / BPV Rules. (2) (Q) When the stamping on a pressure-retaining item becomes indistinct or the nameplate is lost, illegible, or loose, but traceability to the original pressure-retaining item is still possible, can a new nameplate be made and attached to the existing boiler? (A) Yes. All re-stamping must be done in accordance with the original code of construction. Requests for permission to re-stamp or replace nameplates must be made to the jurisdiction in which the pressure-retaining item is located. The jurisdiction may grant such requests if satisfied with the information submitted. Permission from the jurisdiction is not required for the reattachment of nameplates that are loose or not fully attached. When traceability cannot be established, the jurisdiction must be contacted. Ref; 105, 301.4, , (3) (Q) If multiple water heaters were piped together for space heating, would Btu's and volume combine to make the system a boiler? (A) No. See boiler definition Exception 7, NC Dept of Labor Chapter 95. Note: The combined BTU s will be used to calculate combustion and ventilation air requirements. Ref: definition and exception 7, NC Dept. of Labor Chapter 95.

8 Chapter 11 Refrigeration: 1) (Q) An existing chiller is being replaced. The existing chiller uses R-22. The chiller is in an existing mechanical room. The new chiller will be using the more environmentally friendly R-410-A refrigerant. The existing chiller room has a volume of 925 sq. feet and a cu ft. volume of 12,025. The new chiller has 160 lb of R-410A in its largest refrigerant circuit. The chillers quantity exceeds the capacity of the room as provided for in the chart in tbl NC mech. Code. Table has been changed in the 2012 North Carolina code and the quantity of R-410 has been reduced to 25lb/1000 cu. ft. There are no other changes in the code that would change the quantities. Can the code official allow the new code quantities to be used so a separate mechanical room will not be required? (A) Since there are no other changes that would require the designer to build a separate mechanical room the new table quantity is approved as an alternate design. Ref: Table and Table ) (Q) Can recovered refrigerants be re-used by the same owner? (A) Yes. They shall be filtered and dried and they may also be required to be reclaimed if clear signs of contamination exist. Ref; ) (Q) Can reclaimed refrigerants be used in a different owner s equipment? (A) Yes. The refrigerant must be tested and found to meet ARI 700 teat requirements. Ref: Policy: Includes Energy Conservation and Re-Hab Codes 1) (Q) When is a refrigeration permit required? (A) A refrigeration permit is required for any refrigeration equipment required to be assembled (excluding the walk-in cooler box) OR any equipment required to be hard wired electrically (not cord and plug type). 2) (Q) Is the outside air make-up air duct located on the non-insulated side of an attic space in a single family dwelling required to be insulated? (A) No. The temperature difference between the air in the make-up air duct and the air temperature in the attic are not sufficient to cause condensate that would require insulating the duct. Ref: , Exception #2, North Carolina Energy Conservation Code

9 3) (Q)When does a Mechanical Inspector enforce the Carbon Monoxide Alarm requirements adopted by the NC Department of Insurance in One-and-Two-Family Dwellings and Townhouses? Effective date: January 1, (A) 2009 NC Residential Code revisions to Section R313 as provided below: R Carbon Monoxide alarms. In new construction, dwelling units shall be provided with an approved carbon monoxide alarm installed outside of each separate sleeping area in the immediate vicinity of the bedroom(s) as directed by the alarm manufacturer. R Where required-existing dwellings. In existing dwellings, where interior alterations, repairs, fuel-fired appliance replacements, or additions requiring a permit occur, or where one or more sleeping rooms are added or created, carbon monoxide alarms shall be provided in accordance with Section R The required carbon monoxide alarms shall be audible in all bedrooms over background noise levels with all intervening doors closed. Single station carbon monoxide alarms shall be listed as complying with UL 2034 and shall be installed in accordance with this code and the manufacturer s installation instructions. 4) (Q Can R-4 insulated Flex be used in Icynene insulated attics where a thermal barrier is above the ductwork? (A) Yes. It can be used as long as the attic is now part of the thermal envelope and properly sealed. Ref: , NC Energy Conservation Code 5) (Q) Does the code limit the noise level produced by heat pumps and air conditioners? (A) No. There are not any requirements restricting the noise levels of this equipment in the current code. Local ordinances dictate noise levels and are not enforced by building code enforcement officials in Mecklenburg County. 6) (Q) When extending gas pipe to non-electrical gas equipment (barbecue, insert, are you required to bond the existing gas pipe connected to an existing gas or electrical appliance? (A) No, unless the alteration creates the potential to be energized. Administrative Information 1) (Q) A mechanical contractor is adding economizers to existing commercial air conditioning units on a roof. Are permits required to add economizers to the existing units? Are plans required before a permit can be issued? (A) Permits are required per the North Carolina Administrative Code. Plans may be required dependent upon the scope of work and energy code requirements. CTAC usually determines if this information is needed prior to issuing a permit. Ref: North Carolina State Building Code: Administrative Code and Policies 2) (Q) Does the Department of Insurance still maintain a list of third party approved agencies for Electrical, Mechanical, Plumbing and Fuel Gas products? It is my understanding they did away with the list.

10 (A) Yes. The Department of Insurance still has the approve list of third party testing agencies on its web site but only for Electrical and Mechanical Equipment. Go to: bcc third party. ASP 3) (Q) I am a homeowner and I have a complaint about a licensed Mechanical Contractor. The contractor did not complete the work in the contract. Who do I call to file a complaint? (A) Contact John Todaro, he is the area representative for the North Carolina Board of Plumbing, Heating and Fire Sprinkler Contractors. His address is: jtodaro@nclicensing.org.

11 Color code below denotes the calendar year quarter of each question listed above. 1 st 2 nd 3 rd 4th