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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.

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


Appliance categories
Appliance Categories

  • ANSI Venting Categorization


Appliance categorization
Appliance Categorization

Fan Assisted

Forced Draft

Atmospheric

Scotch Marine

Draft Hood

Draft Diverter

I

III

Negative

Positive

Fan Assisted

(high efficiency)

Condensing

II

IV


Acceptable venting material
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


Masonry chimney liners
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


Chimney design equation

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





Draft variations during operation
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


Modulating boiler systems
Modulating Boiler Systems

Gravity Stack Design





Modulating boiler systems1
Modulating Boiler Systems

Controlled Draft Design



National fuel gas code
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


Common code violations
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)


Common code violations1
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.


Common code violations2
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.


Common code violations3
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.


Side wall venting
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.


Side wall venting1
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.


Side wall venting2
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.


Roof top venting
Roof-top Venting

Z223.1-56 (Venting of Equipment)


Gravity stack terminations
Gravity Stack Terminations

NFPA Fig. 12a

NFPA Fig. 12b


Gravity stack terminations1
Gravity Stack Terminations

Experience Shows


Mechanical draft systems defined
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


Mechanical draft systems defined1
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.




Rsib power venter
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



Casv applications stack downsizing
CASV Applications – Stack Downsizing

Hazen High School – Renton, WA

Soldier Field - Chicago, IL


Casv applications aesthetics
CASV Applications - Aesthetics

Rigel – South San Francisco, CA

Getty Center – Los Angeles, CA


Casv applications aesthetics1
CASV Applications - Aesthetics

SBC Center – San Antonio, TX


Casv applications
CASV Applications

National Landmarks

Hospitals

Resorts

Museums

Stadiums

Arenas

Schools


Mods modulating overdraft damper system

MODSModulating Overdraft Damper System



Mods components
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


Mods applications
MODS Applications

Kaiser Center - Oakland, CA

Wells Fargo - Great Falls, MT

Markham Road - Toronto


Mcas mechanical combustion air supply

MCASMechanical Combustion Air Supply


Codes and standards
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


Codes and standards1
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.


Codes and standards2
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


Codes and standards3
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.


Codes and standards4
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


Mcas modulating combustion air supply system
MCAS – Modulating Combustion Air Supply System


Mcas components besf besb fan
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).


Mcas components sfta fan
MCAS Components – SFTA Fan

Seven Models

1,500 – 30,000 cfm

  • Fan can be mounted indoors

  • Impeller – cast allunimum.

  • Housing in steel

  • 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).


Ebc30 modulating control
EBC30 Modulating Control

Chimney Automation System

Modulating Combustion Air Supply System


Mcas mechanical combustion air supply1

MCASMechanical Combustion Air Supply


Sbc center san antonio tx
SBC Center – San Antonio, TX

Two 16 inch ducted combustion air inlets

Instead of

Two 10 foot high by 15 foot long Louvers



Marriott waterfront annapolis md
Marriott Waterfront – Annapolis, MD

One 24 inch ducted combustion air

Instead of one 90 ft.² louver


Mdvs modulating dryer venting system

MDVSModulating Dryer Venting System


Types of clothes dryers
Types of Clothes Dryers

  • Type 1 dryers: “Domestic” dryers to be used primarily in a family living environment.

    • Residences

    • Individual apartments or condominiums

  • Type 2 dryers: “Public” dryers designed to be used in business with direct intercourse of the function with the public.

    • Laundromats

    • Laundry rooms (apartment complexes, dormitories, etc.)

    • Business laundries (hotels, hospitals, health clubs, etc.)


Typical dryer manufacturer s requirements
Typical Dryer Manufacturer’s Requirements

  • Where possible use a single exhaust duct per dryer

  • Dryers are to run with a positive outlet pressure.

    • Type 1 dryers between +0.10 and +0.90 inch W.C.

    • Type 2 dryers between +0.10 and +0.30 inch W.C.

  • Maximum exhaust duct length:

    • Type 1 dryers = 35 equiv. feet (each elbow = 5 feet)

    • Type 2 dryers = 15 equiv. feet (each elbow = 5 feet)


Typical dryer manufacturer s requirements for multiple dryers
Typical Dryer Manufacturer’s Requirements for Multiple Dryers

  • Vertical venting must not exceed 8 feet and can include up to 3 elbows

  • Horizontal venting cannot exceed 15 feet and 1 elbow.


Common exhausting of multiple dryers
Common Exhausting of Multiple Dryers Dryers

  • Common horizontal duct diameter is sized with maximum 0.10 inch W.C. pressure drop

  • Pressure drop in main exhaust shaft is only limited by fan’s total pressure capability

  • Cleanouts must be provided in the common horizontal as well as the main exhaust shaft for removal of lint

  • The BESB fan can be located anywhere down-stream of the last dryer


Use an mdvs for multiple dryer exhausting

Multistory exhausting Dryers

of dryers

Common exhausting of

multiple dryers

Use an MDVS forMultiple Dryer Exhausting


Multistory exhausting of dryers
Multistory Exhausting of Dryers Dryers

  • Type 1 or Type 2 dryers

  • If main exhaust shaft does not need to be fire rated – attach connector to main shaft at 45° as previously shown

  • If main exhaust shaft does need to be fire rated – attach connector via a 22 inch subduct riser as shown

    • Main exhaust shaft and subduct riser must be made of appropriate materials to meet local codes

    • In order to offset the subducts, a square or rectangular main exhaust shaft should be considered


Main issues when common exhausting dryers
Main Issues when DryersCommon Exhausting Dryers

  • For multistory dryer systems where the 22 inch subduct is used to maintain fire rating, a fan MUST BE USED and it must be in operation at all times to comply with code requirements

    • IBC 2006

716.5.3 Penetrations of shaft enclosures. Shaft

enclosures that are permitted to be penetrated by ducts

and air transfer openings shall be protected with

approved fire and smoke dampers installed in accordance

with their listing.

Exceptions:

1. Fire dampers are not required at penetrations

of shafts where:

1.1 Steel exhaust subducts extend at least 22 inches

(559 mm) vertically in exhaust shafts pro-vided

there is a continuous airflow upward to

the outside.

2. In Group B and R occupancies, equipped throughout with and automatic sprinkler system in accordance with Section 903.3.1.1 smoke dampers are not required at penetrations of shafts where:

2.1. Kitchen, clothes dryer, bathroom and toilet room exhaust are installed with steel exhaust subducts, having a wall thickness of 0.019(0.48 mm); and

2.2 That extend at least 22 inches vertically; and

2.3 An exhaust fan is installed at the upper terminus of the shaft, that is powered continuously in accordance with Section 909.11, so as to maintain a continuous upward airflow to the outside.


Multistory exhausting of dryers1
Multistory Exhausting of Dryers Dryers

  • Main exhaust shaft is made of smooth (fire-rated) material

  • Main exhaust shaft sized to max 0.10 inch W.C. pressure drop

  • Access door or cleanout to be located at bottom of main exhaust shaft for lint removal

  • BESB fan can be located anywhere above top most dryer


Mdvs versus single speed

MDVS Dryers

ETL Listed mechanical dryer exhaust system

Usually runs at low rpm = low power

Uses little to no conditioned air = low additional building heat or A/C

Single Speed

No listing for lint-laden air

Runs at full rpm 24 hr/day X 365 days/yr = high power

Uses a large quantity of conditioned air = large additional building heat and A/C

MDVS versus Single Speed


Mdvs versus single speed1
MDVS versus Single Speed Dryers

Location = Atlanta, GA (3000 DDH, 1700 DDC)

Power = $0.10 per KW/h

Heating = $1.00 per therm

A/C = .75 KW/ton X $0.10 per KW/h

Total Annual Savings = $2526


Mdvs mechanical dryer venting system
MDVS Dryers – Mechanical Dryer Venting System


Mdvs components besb fan
MDVS Components - BESB Fan Dryers

Four Models

1200 – 5500 cfm

  • Cast aluminum, backward curved impeller reduces lint build-up. Statically and dynamically balanced with permanently attached balancing weights.

  • Insulated hinged fan housing easily opens to provide easy access to duct and impeller

  • Direct drive with variable speed TEFC motor located outside housing for easy access. Frequency drive should be located inside the building.

  • ETL Listed to UL705 with special consideration for operation with lint-laden air



Mcas modulating combustion air supply for dryers

MCAS DryersModulating Combustion Air Supplyfor Dryers


Why mcas for dryers
Why MCAS for Dryers? Dryers

Make-Up Air.

  • Z223.1-2002

9.4 Clothes Dryers.

9.4.3.2 Provisions for Make-Up Air. Provisions for make-up air shall be provided for Type 2 clothes dryers, with a minimum free area of 1 sq.in. for each 1000 Btu per hr total input rating of the dryer(s) installed.


Manufacturer s requirement
Manufacturer’s Requirement Dryers

  • National Fuel Gas Code requires a minimum free area opening of 1 sq.in./1000 Btuh

  • Most manufacturers require even larger – approximately 1 sq.in / 700 Btuh. Ex. A twin 30# tumbler dryer with a total input of 204,000 Btuh (1100 cfm) requires a minimum 2 sq.ft. free area opening.

  • Most laundry facilities have problems with make-up air. The industry believes it is one of their biggest problems.


Mcas components sfta fan1
MCAS Components – SFTA Fan Dryers

Seven Models

1,500 – 30,000 cfm

  • Fan can be mounted indoors

  • Impeller – cast allunimum.

  • Housing in steel

  • 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).


Marriott waterfront annapolis md1
Marriott Waterfront – Annapolis, MD Dryers

One 24 inch ducted combustion air inlet

Instead of

One 90 ft.² louver


Simulators casv mcas mdvs

Simulators DryersCASV / MCASMDVS


Thank You! Dryers


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