1 / 77

EXHAUSTO: Venting Design

EXHAUSTO: Venting Design. Appliance Categories ASHRAE Equation & Chimney Pressures Common Code Violations Chimney Automation Systems Combustion Air Supply Boiler Room Simulator Overdraft Damper System Dryer Venting. Appliance Categories. ANSI Venting Categorization. Appliance Categorization.

shima
Télécharger la présentation

EXHAUSTO: Venting Design

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EXHAUSTO: Venting Design

  2. Appliance CategoriesASHRAE Equation & Chimney Pressures Common Code Violations Chimney Automation Systems Combustion Air SupplyBoiler Room SimulatorOverdraft Damper SystemDryer Venting

  3. Appliance Categories • ANSI Venting Categorization

  4. Appliance Categorization Fan Assisted Forced Draft Atmospheric Scotch Marine Draft Hood Draft Diverter I III Negative Positive Fan Assisted (high efficiency) Condensing II IV

  5. Acceptable Venting Material Atmospheric Fan Assisted Forced Draft UL103 P-Stack Welded Steel B-Vent Masonry (interior) B-Vent Masonry I III Negative Positive Condensing Fan Assisted (85+ efficiency) II IV (90+ efficiency) AL29-4C single wall CPVC (tested with appliance) (85 – 90 % efficiency) AL29-4C double wall AL29-4C double wall

  6. Masonry Chimney Liners Reference: ANSI Z223.1-2002 10.4.1 and 13.1.9, NFPA211 4-2.2 • Atmospheric • Fan Assisted • Forced Draft • Clay tile liner • Clay tile liner (interior chimney) • Steel liner (exterior chimney) Exception: Clay tile liner can be used with exterior chimney if an Atmospheric appliance is connected to the same chimney • Positive pressure steel liner Ex. Welded steel, Inner liner of pressure stack I III Negative Positive II IV • Condensing • Fan Assisted • (85+ efficiency) • AL29-4C Liner • AL29-4C Liner

  7. 1996 Edition Theoretical Draft (-) Pressure Losses (+) Outlet Pressure Chimney Design Equation • INPUTS: • Appliance Type • Fuel Type • MBH Input • CO2% in Flue Gases • Flue Gas Temperature • Ambient Temperature • Altitude • Flue Layout + • RESULTS: • Flue Gas Volume • Flue Gas Velocity • Theoretical Draft • Total Pressure Losses • Appliance Outlet Pressure

  8. Boiler Efficiency versus Draft

  9. Annual Draft Variations

  10. Chimney Draft – Steady-State

  11. Draft Variations During Operation Vent = 30’ vert./10’ horiz., 18” diam. 4 Fan-assisted Cat I boilers with 1,000 MBH input each Constant ambient of 60°F Draft requirement: 0.05”WC

  12. Modulating Boiler Systems Gravity Stack Design

  13. Chimney Automation Systems

  14. CASV – Chimney Automation System

  15. CASI – Chimney Automation System

  16. Modulating Boiler Systems Controlled Draft Design

  17. First Cost Analysis

  18. National Fuel Gas Code NFPA 54 IFGC ANSI Z 223.1 • Horizontal distances • Large stack area • Self venting connector rise • Fan Min capacities • Different type of appliances • Existing masonry chimneys • Location of draft inducer

  19. Common Code Violations Chimney Automation System (NFPA 54) Z223.1-2002 (Venting of Equipment) 10.6.1.4 The total horizontal distance of a vent plus the horizontal vent connector serving draft hood-equipped appliances shall not be greater than 75 % of the vertical height of the vent. Table 13.1 and 13.2 The total horizontal length of the vent plus the vent connector for a single Category I appliance is: 100% of the height (vent 6 – 30 ft high); 30 ft (vent 31 – 50 ft high); 50% of the height (vent 51 – 100 ft high)

  20. Common Code Violations Chimney Automation System (NFPA 54) Z223.1-2002 13.2 (Sizing of Venting Systems) 13.2.2 The maximum vent connector horizontal length shall be 18 in./in of connector diameter. 13.2.4 The length of the common vent manifold shall not exceed 18 in./in. of common vent diameter. 13.2.5 The horizontal length of the common vent offset shall not exceed 18 in./in. of common vent diameter.

  21. Common Code Violations Chimney Automation System (NFPA 54) Z223.1-2002 13.2.17 (Sizing of Venting Systems) 13.2.17 Where two or more appliances are connected to a vertical vent or chimney, the flow area of the largest section of vertical or chimney shall not exceed seven times the smallest listed appliance categorized vent areas, flue collar area, or draft hood outlet area unless designed in accordance with approved engineering methods.

  22. Common Code Violations Chimney Automation System (NFPA 54) Z223.1-2002 10.10.4.2 (Venting of Equipment) 10.10.4.2 Vent connectors serving Category I appliances shall not be connected into any portion of mechanical draft systems operating under positive static pressure, such as those serving Category III or Category IV appliances.

  23. Side-wall Venting Z223.1-51-2002 (Venting of Equipment) 10.3.4.6 Mechanical Draft Systems. The exit terminals of mechanical draft systems shall be not less than 7ft above grade where located adjacent to public walkways.

  24. Side-wall Venting Z223.1-56 (Venting of Equipment) 7.8 Venting System Location. (a) A Venting system shall terminate at least 3 ft (0.9 m) above any forced air inlet located within 10 ft (3.1 m). Exception No. 1: This provision shall not apply to the combustion air intake of a direct-vent appliance. Exception No. 2: This provision shall not apply to the separation of circulating air inlet and flue gas discharge of listed outdoor appliances.

  25. Side-wall Venting Z223.1-56 (Venting of Equipment) 7.8 Venting System Location. (b) The venting system of other than a direct-vent appliance shall terminate at least 4 ft (1.2 m) below, 4 ft (1.2 m) horizontally from, or 1 ft (30 cm) above any door, window, or gravity air inlet into any building. The bottom of the vent terminal shall be located at least 12 in. (30 cm) above grade.

  26. Roof-top Venting Z223.1-56 (Venting of Equipment)

  27. Gravity Stack Terminations NFPA Fig. 12a NFPA Fig. 12b

  28. Gravity Stack Terminations Experience Shows

  29. Mechanical Draft Systems Defined 10.3.4.1 Mechanical draft systems shall be listed and shall be installed in accordance with the terms of their listing and both the appliance and the mechanical draft system manufacturer’s instructions. 10.3.4.2 Gas utilization equipment requiring venting shall be permitted to be vented by means of mechanical draft systems of either forced or induced draft design. Exception: Incinerators 10.3.4.5 Where a mechanical draft system is employed, provision shall be made to prevent flow of gas to the main burners when the draft system is not performing so as to satisfy the operating requirements of the equipment for safe performance Z223.1-2002 Standard for Venting of Equipment

  30. Mechanical Draft Systems Defined 503.6.9.3 Mechanical draft. Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods. IFGC - Section 503 (Venting of Equipment) Z223.1-2002 Standard for Venting of Equipment 10.5.3.1 Size of Chimneys. Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods.

  31. CASV – Chimney Automation System

  32. CASI – Chimney Automation System

  33. RSIB – Power Venter • SS16 construction • Removable access door • Direct drive • Class A insulated motor - eliminates the need for secondary fan cooling • Maintenance free • 575 ºF Continuous Duty • UL 378 – Draft Equipment • The RSIB fan can vent category I, II, III and IV appliances with or without barometric dampers • Simple design with few components reduces the risk of failure and simplifies service • RSIB is of Type B, Spark Resistant Construction

  34. Installation Options - RSIB

  35. CASV Applications – Stack Downsizing Hazen High School – Renton, WA Soldier Field - Chicago, IL

  36. CASV Applications - Aesthetics Rigel – South San Francisco, CA Getty Center – Los Angeles, CA

  37. CASV Applications - Aesthetics SBC Center – San Antonio, TX

  38. CASV Applications National Landmarks Hospitals Resorts Museums Stadiums Arenas Schools

  39. MODSModulating Overdraft Damper System

  40. Modulating Overdraft Damper System

  41. MODS Components • MDF Damper • Sizes – 12 in. to 48 in. diameters • Multiple opposed blades made of 16 gauge type 316 stainless • Pressure stack flange connections • Rated to 700°F • EBC30 • Prime function • Additional over-pressure protection for Forced-draft boilers

  42. MODS Applications Kaiser Center - Oakland, CA Wells Fargo - Great Falls, MT Markham Road - Toronto

  43. MCASMechanical Combustion Air Supply

  44. Codes and Standards Code Requirements – Air for Combustion and Ventilation • Z223.1-2002 8.3.3 Outdoor Combustion Air. • 8.3.3.1 Two Permanent Openings Method. Two permanent openings, one commencing within 12 in. of the top and one commencing within 12 in. of the bottom of the enclosure, shall be provided. The openings shall communicate directly, or by ducts, with the outdoors or spaces that freely communicate with the outdoors as follows: • Where directly communicating with the outdoors or through vertical ducts, each opening shall have a minimum free area of • 1 in.²/4000 Btu of total input rating of all equipment in the enclosure. • (2) Where communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of not less than 1in.²/2000 Btu of total input rating of all equipment in the enclosure

  45. Codes and Standards Code Requirements – Air for Combustion and Ventilation • Z223.1-2002 8.3.3 Outdoor Combustion Air. • 8.3.3.2 One Permanent Opening Method: One permanent opening, commencing within 12 in. of the top of the enclosure, shall be provided. The opening shall directly communicate with the outdoors or shall communicate through a vertical or horizontal duct to the outdoors or spaces that freely communicate with the outdoors and shall have a minimum free area of the following: • 1 in.²/3000 Btu of the total input rating of all equipment located in the enclosure, and • Not less than the sum of the areas of all vent connectors in the space.

  46. Codes and Standards Sizing of Gravity Louvers • Louver(s) Sizing: • 1 sq.in./4000 Btu per louver • 4000 MBH = 1000 in2 • of free area per louver. • Typical louver has 30-60% free area. • Depending on louver design actual louver size will be: • Using 45% free area louvers = Two 5’ x 4’ louvers 2000 MBH 2000 MBH

  47. Codes and Standards Code Requirements – Air for Combustion and Ventilation – Mechanical Combustion Air Supply (MCAS) • Z223.1-2002 8.3.6 Mechanical Combustion Air Supply. Where all combustion air is provided by a mechanical air supply system, the combustion air shall be supplied from outdoors at the minimum rate of 0.35 ft³/min per 1000 Btu/hr for all appliances located within the space. 8.3.6.1 Where exhaust fans are installed, additional air shall be provided to replace the exhausted air. 8.3.6.2 Each of the appliances served shall be interlocked to the mechanical air supply system to prevent main burner operation where the mechanical air supply system is not in operation.

  48. Codes and Standards Sizing of Mechanical Combustion Air • Louver Sizing: • Engineered using ASHRAE Chimney Design Equation. • Flue Gas Volume corrected for temperature • = 1,400 cfm of combustion air • 1400 cfm/500 fpm • = 2.8 ft2 of louver free area • Using a 45% free area louver • = One 3’ x 2’ louver 2000 MBH 2000 MBH

  49. MCAS – Modulating Combustion Air Supply System

  50. MCAS Components – BESF/BESB Fan Seven Models 450 – 5500 cfm • Fan can be mounted indoors or outdoors. • Impeller - statically and dynamically balanced. • Insulated housing in galvanized steel • Hinged fan housing easily opens to provide easy access to duct and impeller • Direct drive, variable speed, TEFC motor located outside housing for easy access. • Variable Frequency Drive is used on three phase models (VFD should be located inside the building).

More Related