Answers and Analysis
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Questions matching UMC Chapter 8
10 results
UMC 2003 801.1
UMC 2006 801.1
UMC 2009 801.1
UMC 2012 801.1
Topic: Connectors
1. Does the UMC harmonize its provisions for the clearances for connectors as stated in NFPA 211? We have a Peerless sectional cast iron unit (1,200,000 Btu input), AGA listed for use with a B-vent with draft hood, and noncombustible construction.
2. How do we determine and support which equipment class the boiler should be under?
2. How do we determine and support which equipment class the boiler should be under?
1. Yes, Section 801.1 states that low heat appliances shall be vented in accordance with this chapter and that other gas appliances shall be vented in accordance with NFPA 211 or other applicable standards.
2. Generally, the equipment classification will be supported by the equipment listing. This chapter only covers low-heat appliances (appliances producing combustion gases not in excess of 1,000°F under normal operating conditions, but capable of producing combustion gases of 1,400°F during intermittent forced firing for periods up to one hour).Therefore, the flue gases at the appliance flue outlet will determine if this code shall be used or if NFPA 211 is the correct applicable standard. Your boiler is most likely a low-heat appliance, which would be classified under, “listed equipment with draft hoods and equipment listed for use with Type B vents,” as noted in Table 8-2 (2003/2006/2009)or T802.7.3.4(1)/2012.
2. Generally, the equipment classification will be supported by the equipment listing. This chapter only covers low-heat appliances (appliances producing combustion gases not in excess of 1,000°F under normal operating conditions, but capable of producing combustion gases of 1,400°F during intermittent forced firing for periods up to one hour).Therefore, the flue gases at the appliance flue outlet will determine if this code shall be used or if NFPA 211 is the correct applicable standard. Your boiler is most likely a low-heat appliance, which would be classified under, “listed equipment with draft hoods and equipment listed for use with Type B vents,” as noted in Table 8-2 (2003/2006/2009)or T802.7.3.4(1)/2012.
UMC 2003 802.6.4
UMC 2006 802.6.4
UMC 2009 802.6.4
UMC 2012 802.6.4, 802.6.5 & 802.6.6
Topic: Multiple Appliance Venting
Section 802.6.4 states that multiple appliance venting shall be located within the same floor of the building, except engineered venting systems. Can two-story apartment buildings with an appliance on each floor use the provisions of Section 802.6.4 to comply with the intent of the code? Multiple-story apartment buildings with water heaters serving each floor level have multiple roof penetrations, thereby increasing the potential for leaks and other structural problems.
No. Section 802.6.4 requires that appliances which are connected to one common venting system shall be located within the same story of the building except for engineered venting systems as provided in Section 801.0.
Section 802.6.4 simply explains how vents are sized when two or more appliances within the same story of the building are connected to one common gravity-type venting system.
Section 802.6.4 simply explains how vents are sized when two or more appliances within the same story of the building are connected to one common gravity-type venting system.
UMC 2003 802.7
UMC 2006 802.7
UMC 2009 802.7
UMC 2012 802.7
Topic: Single Wall Gas Vents
1. Is 5/8 inch Type X gypsum wallboard considered combustible per the UMC in reference to clearances from single-wall gas vents?
2. Would it be acceptable per the UMC to reduce the clearances between a single-wall gas vent and 5/8 inch Type X gypsum wallboard by applying paint to the wallboard?
2. Would it be acceptable per the UMC to reduce the clearances between a single-wall gas vent and 5/8 inch Type X gypsum wallboard by applying paint to the wallboard?
1. Yes. Gypsum wallboard does not meet the definition of noncombustible as defined in Section 216.0.
2. No. Acceptable methods of clearance reduction can be found in Table 3-2 as per footnote 2 of Table 3-3 (2003/2006) Table 3-4 (2009)and T303.3(2)(2012). Other methods of clearance reduction would be considered an alternate method.
2. No. Acceptable methods of clearance reduction can be found in Table 3-2 as per footnote 2 of Table 3-3 (2003/2006) Table 3-4 (2009)and T303.3(2)(2012). Other methods of clearance reduction would be considered an alternate method.
UMC 2003 802.10.2
UMC 2006 802.10.2
UMC 2009 802.10.2
UMC 2012 802.10.1
Topic: Insulated Connector
Is a Type B gas vent equal to an insulated type connector?
Yes. A Type B vent is an insulated connector. The code states in part, that a portion of the connector shall be listed Type B or Type L vent material or be provided with equivalent means of insulation. This means equivalent to the thermal resistance of those vent systems.
UMC 2003 802.10.2.4
UMC 2006 802.10.2.4
UMC 2009 802.10.2.4
UMC 2012 802.10.1.2
Topic: Single Wall Gas Vents
1. Is an attached garage (unheated and uninsulated space with ventilation from the outside) considered a "cold area"? If so, then would a Type B or Type L vent connector be required?
2. Does the definition of "cold area" include a garage?
2. Does the definition of "cold area" include a garage?
1. Yes, the garage is considered a cold area. The UMC requires a Type B or L vent or other equivalent means of insulation.
2. A "cold area" is defined as having or being a temperature that is uncomfortably low for humans and not heated. In summary, the object is to prevent condensation. The interpretation of a "cold area" will depend on climate and the opinion of the Authority Having Jurisdiction.
2. A "cold area" is defined as having or being a temperature that is uncomfortably low for humans and not heated. In summary, the object is to prevent condensation. The interpretation of a "cold area" will depend on climate and the opinion of the Authority Having Jurisdiction.
UMC 2003 802.10.14.1, see also 802.10.9.9
UMC 2006 802.10.14.1, see also 802.10.9.9
UMC 2009 802.10.14.1, see also 802.10.9.9
UMC 2012 802.10.12, see also 802.10.7.1
Topic: Connectors
If the vent connector is required to be "installed within the space or area in which the appliance is located and shall be connected to a chimney or vent" and "connectors shall be short and straight as possible," then that portion of a pipe that leaves the "space or area" of the appliance might be considered a vent and not vent connector, therefore needs to meet vent requirements? If required to be as short as possible, would the length at this vent connector be contrary to that requirement?
Yes. The code allows a vent connector from a listed gas appliance with a draft hood to pass through walls or partitions if they are Type B or L vents installed according their listings. In addition, single wall metal pipe may be used when installed with a ventilated thimble. The code also allows the horizontal portion of the vent system to equal the vertical height. Note: The UMC limits single-wall penetrations to exterior walls only.
UMC 2003 803.1.7
UMC 2006 803.1.7
UMC 2009 803.1.7
UMC 2012 803.1.9
Topic: Sizing Category I Venting Systems
The flow area of the vertical vent shall not exceed seven times the flow area of the listed appliance categorized vent area, flue collar area, or draft hood outlet area. Does this apply to solid fuel and gas masonry fireplaces built on site? I say yes because it has a flue collar.
No. Masonry chimneys serving solid-fuel-burning appliances shall be built and installed in accordance with NFPA 211. Section 803.0 (2003/2006/2009/2012) is only applicable to Category I venting systems that serve listed gas-burning appliances.
UMC 2003 803.2.4, see also 803.2.6
UMC 2006 803.2.4, see also 803.2.6
UMC 2009 803.2.4, see also 803.2.6
UMC 2012 803.2.3, see also 803.2.5
Topic: Sizing Category I Venting Systems
By referencing Section 802.5.3(3) or 802.5.5.3 (2012), for sizing two draft hood equipped appliances, is it allowed to put unlimited pipe and elbows both horizontal and vertical in the system?
No. The length of horizontal runs and changes in direction for a Category I venting system are limited per Sections 803.2.4 and 803.2.6.
UMC 2006 802.3.4.6
UMC 2009 802.3.4.6
UMC 2012 802.3.3.5
Topic: Mechanical Draft Systems
Must the vent termination for a direct vent appliance meet section 802.3.4.6?
Yes, section 802.3.4.6 would apply if the direct vent appliance uses a mechanical draft system.
UMC 2018 802.2.6
Topic: Chimneys and Vents
Can high efficiency (Category IV) appliances be common manifolded on the vent?
No, requirements are given in the Uniform Mechanical Code for installation of Category II, III or IV appliances using a common vent in multiple-story buildings.