AHJ – Authority Having Jurisdiction. Refers to a governmental organization or designated individual with legal responsibility for building codes, standards and inspection.
Air Quality Standards – The level of pollutants prescribed by law or regulation that cannot be exceeded during a specified time in a defined area.
AL 29-4C® - Superferritic stainless steel designed and produced by Allegheny Ludlum used in UL 1738 listed chimneys for venting Category II, III & IV appliances
Aluminized Steel - Steel on which an aluminum coating is applied to resist corrosion.
Ambient Temperature - The temperature at a point or area expressed as an average of the surrounding areas or materials. Ambient temperature is generally given to be 70-80°F (21 TO 27°C); an average of daily and seasonal variation.
Approved - Acceptable to the code official or other authority having jurisdiction.
ASHRAE - American Society of Heating, Refrigerating and Air Conditioning Engineers. Schebler Chimney Systems is a member.
ASME - The American Society of Mechanical Engineers. Schebler certification: ASME code for pressure vessel fabrication and repair.
Atmospheric Appliance - An appliance which requires natural draft for venting. Venting is under negative pressure.
B-Vent - A type B venting product with an aluminum inner liner and galvanized outer shell. Rated to 550 degrees. Nonpositive pressure rated.
Barometric Damper - A balanced air damper to allow outside air into the vent system to equalize the draft.
Barometric Pressure - Atmospheric pressure as determined by a barometer.
Blower - A fan used to force air under pressure.
Boiler - A closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating.
Boiler Efficiency - Difference between the energy input and energy output in a boiler.
Boiler Horsepower - Measure of a boiler’s capacity to produce steam.
Breeching - The horizontal portion of a chimney system or grease duct from the boiler, hot water heater, generator, dishwasher or kitchen appliance hood to the vertical portion of the system.
BTU - Abbreviation for British thermal unit, which is the quantity of heat required to raise the temperature of 1pound (454 g) of water 1°F (0.56°C) (1 Btu = 1055 J).
Building Heating Appliance - A fuel-burning or electric boiler operating at a gauge pressure not over 50 psi.
Burner - A burner introduces the mixture of fuel and air into an appliance at the desired rate per the specific appliance requirements.
Category I Appliance - An appliance that operates with a nonpositive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.
Category II Appliance - An appliance that operates with a nonpositive vent static pressure and with a gas vent temperature that is capable of causing excessive condensate production in the vent.
Category III Appliance - An appliance that operates with a positive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.
Category IV Appliance - An appliance that operates with a positive vent static pressure and with a vent gas temperature that is capable of causing excessive condensate production in the vent.
Chimney - A primarily vertical structure containing one or more flues for the purpose of carrying gaseous products of combustion and air from an appliance to the outside atmosphere.
Factory-built chimney - A listed and labeled chimney composed
of factory-made components assembled in the field in accordance with manufacturer's instructions and the conditions of the listing.
Masonry chimney - A field-constructed chimney composed
of solid masonry units, bricks, stones or concrete.
Metal chimney - A field-constructed chimney of metal.
Clearance to Combustibles - Distance required per UL listing between the single wall liner or outer shell of the double wall products to combustible material such as a shaft, roof, etc.
Clean Out - A spot in the chimney system or grease duct where inspection or cleaning of the system can be made. Done with a 90T or 90Y.
Continuous Weld - A metal joining method that produces a product without visible interruption or variation in quality.
Code - These regulations, subsequent amendments thereto or any emergency rule or regulation that the administrative authority having jurisdiction has lawfully adopted.
Code Official - The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative.
Condensate - The liquid that separates from gas, including flue gas, due to a reduction in temperature.
Corrosion - Eating away of metal due to chemical reaction. Schebler’s continuous seam welding and absence of spot welds minimizes chimney corrosion. (SEE Solutions > Corrosion Resistant)
cUL – Canadian Underwriters Laboratory. Schebler products carry specific certifications indicating satisfaction of safety standards set by Canadian Underwriters Laboratories. Also indicated by ULC (Underwriters Laboratory of Canada.)
Damper - A manually or automatically controlled device to regulate draft or the rate of flow of air or combustion gases.
Draft - The pressure difference existing between the appliance or any component part and the atmosphere, that causes acontinuous flow of air and products of combustion through thegas passages of the appliance to the atmosphere.
Mechanical or induced draft - The pressure difference created by the action of a fan, blower or ejector that is located between the appliance and the chimney or vent termination.
Natural draft - The pressure difference created by a vent or chimney because of its height, and the temperature difference between the flue gases and the atmosphere.
Dew Point - The temperature at which condensation starts.
Diameters, chimney – At up to 18’ in diameter, Schebler chimneys are the largest available. In any application, chimney diameters greater than 26” reduce cost and space of venting multiple boilers – fewer stacks, fewer roof penetrations, lower costs.
Direct-Vent Appliances - Appliances that are constructed and installed so that all air for combustion is derived.
Double Wall – A chimney constructed of an inner liner and outer shell, reducing conduction of heat to the outside. This allows the chimney to be installed without combustion danger to support materials.
Draft -The rising gas creates a pressure difference called draft, which draws combustion air into the appliance and expels the exhaust gas outside through the chimney.
Draft Hood - Located at the top of an atmospheric appliance where the breeching or chimney connects. Draft hood helps bring outside air into the vent to help draft.
Efficiency - The ratio of input of energy to output of energy
Engine Generator - device that converts mechanical energy into electrical energy with its own engine.
Engineered Stack - A chimney that is engineered to be self-supporting or free-standing. Schebler’s engineered stack expertise includes sizing, design, engineering, fabrication and installation. (See Engineered Stacks)
eVent SeriesTM - Prefabricated chimney system for high-efficiency condensing boilers. Three models are available in odd and even sizes from 5" to 48". UL 1738-Listed, corrosion-resistant, 24 and 20 gauge, AL 29-4C stainless steel products. (See Prefabricated Chimneys for links to all eVent models).
Fire Resistance Rating - The time, in minutes or hours, that materials or assemblies have withstood a fire exposure as established in accordance with the test procedures of
Field Fabricated – Non-UL fabrication of grease duct, flue, breeching or chimney products.
Flange Connection - ½” rolled lip on Schebler products that allows secure connection of products. Schebler’s flange connection increases pressure rating and eliminates condensate leakage.
Flanged Boiler Connection - Boiler outlet that has a rolled lip and requires a flanged boiler kit.
Flue - A passage for products of combustion – hot air, gas, steam or smoke; chimney.
Flue Gases - Products of combustion plus excess air in applianceflues or heat exchangers.
Flue Liner (Lining) - A system or material used to form the inside surface ofa flue in a chimney or vent, for the purpose of protecting the surrounding structure from the effects of combustion products and for conveying combustion products without leakage to the atmosphere.
Fuel Gas - A natural gas, manufactured gas, liquefied petroleum gas or mixtures of these gases.
Forced Draft - Air under positive pressure produced by fans at the point where air or gases enter a unit, such as a combustion furnace.
FyreGuard™ - double wall UL 1978-listed and UL 2221 Classified grease duct product, zero-clearance to combustibles and 2-hour fire rating. This eliminates the need for a fire-rated chase and secondary insulation.
Grease Ducts. A containment system for the transportation of air and grease vapors that is designed and installed to reduce the possibility of the accumulation of combustible condensation and the occurrence of damage if a fire occurs within the system.
Generator - a device that converts mechanical energy into electrical energy.
Guy Section – a bracing attachment for tall chimney structures that provides protection from wind displacement.
Heavy Wall Fabrication – An integral part of Schebler engineered stack production, featuring AWS-certified welders with expertise in a variety of high-integrity metals.
IMC - International Mechanical Code. Establishes minimum regulations for mechanical systems using prescriptive and performance-related provisions.
Induced Draft Fan - A fan located inside a system to assist exhaust of flue gas.
Insulation – Ceramic fiber material of various thicknesses used in Schebler chimney models to reduce cold-face temperatures and lower building cooling loads; to enable tight installations by reducing clearance to combustibles; and to diminish heat loss in low temperature environments.ISO – International Organization for Standardization. Schebler’s ISO 9001:2000 certification indicates fulfillment of worldwide quality management requirements.
Labeled - Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation that maintains periodic inspection of the production of the above-labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.
Listed - Equipment, materials, products or services included in a list published by an organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose.
Liner – The interior component of a double-wall chimney. Schebler 304, 317 and AL29-4C stainless steel liners are designed to last for decades under a variety of uses and conditions.
Combustible Material - Any material that will burn regardless of its auto ignition temperature.
Noncombustible Material - A substance that will not ignite and burn when subjected to a fire.
Make Up Air - Outside air introduced into mechanical room to help draft.Modulating - Modulating or throttling is the action of a control from its maximum to minimum position in either predetermined steps or increments of movement as caused by its actuating medium.
NFPA - National Fire Protection Association – an International Codes and Standards Organization.
NFPA 37 - Standard for the installation and use of stationary combustion engines and gas turbines.
NFPA 96 - Standards for ventilation control and fire protection of commercial cooking operations.
NFPA-211 - Standards for chimneys, fireplaces, vents and solid fuel burning appliances.
Obround – a space-conserving chimney shape consisting of two semicircles connected by parallel straight sides.
Offset (Vent) - A combination of approvedbends that makes two changes in direction bringing one section of the vent out of line but into a line parallel with the other section.
Pressure Drop - The loss in pressure due to friction or obstruction in pipes, valves, fittings, regulators and burners.
Pressure Test - An operation performed to verify the gas-tight integrity of gas piping following its installation or modification.Pressure Relief Valve. A pressure-actuated valve held closed by a spring or other means and designed to relieve pressure automatically in excess of the device's setting.
Rain Test – UL test indicating that an unsatisfactory amount of water does not enter the rain cap of a chimney.
Sequence Draft Control™ - Schebler’s design service which offers boiler manufacturers and building owners a complete engineered venting system which maintains consistent stack pressure for hot water or steam appliances within manufacturer requirements. This system automatically compensates for all operating conditions ensuring proper appliance operation with common vented systems.
Shaft - An enclosed space extending through one or more stories of a building, connecting vertical openings in successive floors, or floors and the roof.
Skin Temperature Rise Tests – UL study subjecting a chimney to a series of burn tests at temperatures up to 1800° F. Determines safe clearances from the chimney outer shell to combustible materials.
SlimVent™ - the industry’s only double wall UL 1978-listed and UL 2221 Classified grease duct product that is designed as a safer alternative to field fabricated non-UL-listed grease ducts. SlimVent is designed for low overhead clearances where no round grease duct will fit.
Special Gas Vent - Vents intended for use with listed Category II, III, and IV appliances, and are investigated in accordance with the Standard for Safety for Venting Systems for Categories II, III and IV Gas-Burning Appliances, UL 1738.
Stack - A vertical conduit, which due to the difference in density between internal and external gases creates a draft at the base.
Stainless Steel - Material with different levels of corrosiveness used as the liner in UL listed chimneys and grease duct.
Structural Tests – UL study indicating support plates and wall supports have been physically tested to carry a load four times that allowed by the UL listing.
Thermal Expansion - Alteration to temperature inside a chimney or grease duct system that causes the metal surfaces to expand.
Tool-less End Cap – UL-listed end cap used on grease duct that doesn’t require tools to remove, making inspection and cleaning easier at clean out locations.
UL - Underwriters Laboratories. Schebler Chimney Systems products carry specific certifications indicating satisfaction of safety standards set by Underwriters Laboratories. cUL and ULC refer to Canadian requirements.
UL 103 - Safety standard for prefabricated chimneys intended for venting gas, liquid, and solid-fuel fired residential-type appliances and building heating appliances.
UL 1738 - Safety standard for venting systems intended for gas-burning appliances, Categories II, III and IV
UL 1978 - Standard for grease ducts and their clearance to combustibles.
UL 2221 - Indicates a zero-clearance to combustibles for fire-resistive grease ducts.
Vee Band - A stainless steel V-shaped band that draws the flanges together on two pieces of chimney products, securing them together.
Vent - A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products and air to the atmosphere, listed and labeled for use with a specific type or class of appliance.
Special gas vent - A vent listed and labeled for use with listed Category II, III and IV appliances.
Type B vent - A vent listed and labeled for use with appliances with draft hoods and other Category I appliances that are listed for use with Type B vents.
Type BW vent - A vent listed and labeled for use with wall furnaces.
Type L vent - A vent listed and labeled for use with appliances that are listed for use with Type L or Type B vents.
Vent Gases - Products of combustion from appliances plus excess air plus dilution air in the vent connector, gas vent or chimney above the draft hood or draft regulator.
Venting System - A continuous open passageway from the flue collar or draft hood of an appliance to the outside atmosphere for the purpose of removing flue or vent gases. A venting system is usually composed of a vent or a chimney and vent connector, if used, assembled to form the open passageway.
Forced-draft venting system - A portion of a venting system using a fan or other mechanical means to cause the removal of flue or vent gases under positive static vent pressure.
Induced draft venting system - A portion of a venting system using a fan or other mechanical means to remove flue or vent gases under nonpositive static vent pressure.
Mechanical draft venting system -A venting system designed to remove flue or vent gases by mechanical means, that consists of an induced draft portion under nonpositive static pressure or a forced draft portion under positive static pressure.
Natural draft venting system - A venting system designed to remove flue or vent gases under nonpositive static vent pressure entirely by natural draft.
Water Column - The amount of gas pressure necessary to displace a column of water a specified number of inches. 28 inches of water column equals 1 psi.
Wind Load Tests – UL test indicating load equivalents to 110-mph wind have been applied to the chimney with acceptable results.