A furnace is a device used for heating. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature The name derives from Latin fornax, oven. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. An oven is an enclosed compartment for Heating, Baking or Drying.
In American English, the term furnace on its own is generally used to describe household heating systems based on a central furnace (known either as a boiler or a heater in British English), and sometimes as a synonym for kiln, a device used in the production of ceramics. Phonology North American English regional phonology In many ways compared to English English, North American English is conservative in its Phonology. House generally refers to a Shelter or Building that is a Dwelling or place for Habitation by Human beings. A boiler is a closed vessel in which Water or other Fluid is heated A heater is any object that emits Heat or causes another body to achieve a higher Temperature. Kilns are thermally insulated chambers or Ovens in which controlled temperature regimes are produced The word ceramic is derived from the Greek word κεραμικός ( keramikos) In British English the term furnace is used exclusively to mean industrial furnaces which are used for many things, such as the extraction of metal from ore (smelting) or in oil refineries and other chemical plants, for example as the heat source for fractional distillation columns. British English or UK English ( BrE, BE, en-GB) is the broad term used to distinguish the forms of the English language used in the For other uses of this term see Industry (disambiguation An industry (from Latin industrius, "diligent industrious" The related terms resource extraction and resource extraction industry both refer to the practice of locating acquiring and selling any resource but typically a Natural The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining Chemical reduction, or smelting, is a form of Extractive metallurgy. An oil refinery is an industrial Process plant where Crude oil is processed and refined into more useful Petroleum products, such as Gasoline Fractional distillation is the separation of a mixture into its component parts or fractions such as in separating Chemical compounds by their Boiling point by heating
The term furnace can also refer to a direct fired heater, used in boiler applications in chemical industries or for providing heat to chemical reactions for processes like cracking, and is part of the standard English names for many metallurgical furnaces worldwide. English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States
The heat energy to fuel a furnace may be supplied directly by fuel combustion, by electricity such as the electric arc furnace, or through induction heating in induction furnaces. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. Induction heating is the process of Heating an electrically conducting object (usually a Metal) by Electromagnetic induction, where Eddy currents An induction furnace is an electrical Furnace in which the heat is applied by Induction heating of a conductive medium (usually a Metal) in a Crucible
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Household Furnaces
A household furnace is a major appliance that is permanently installed to provide heat to an interior space through intermediary fluid movement, which may be air, steam, or hot water. The household is the basic unit of analysis in many Social, Microeconomic and Government models Refrigerator1svg|left|100px]]A major appliance, or domestic appliance, is usually defined as a large Machine which accomplishes some routine housekeeping task which Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Water is a common Chemical substance that is essential for the survival of all known forms of Life. The most common fuel source for modern furnaces in the United States is natural gas; other common fuel sources include LPG (liquefied petroleum gas), fuel oil, coal or wood. Fuel is any material that is burned or altered in order to obtain energy The United States of America —commonly referred to as the Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Liquefied petroleum gas (also called LPG, GPL, LP Gas, or Autogas) is a mixture of Hydrocarbon Gases used as a Fuel Fuel oil is a fraction obtained from Petroleum Distillation, either as a distillate or a residue Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs In some cases electrical resistance heating is used as the source of heat, especially where the cost of electricity is low. Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is
Combustion furnaces always need to be vented to the outside. Traditionally, this was through a chimney, which tends to expel heat along with the exhaust. A chimney is a system for venting hot Flue gases or Smoke from a Boiler, Stove, Furnace or Fireplace to the outside Modern high-efficiency furnaces can be 98% efficient and operate without a chimney. In Thermodynamics, the thermal efficiency (\eta_{th} \ is a dimensionless performance measure of a thermal device such as an Internal combustion The small amount of waste gas and heat are mechanically ventillated through a small tube through the side or roof of the house.
- "High-efficiency" in this sense may be misleading, because furnace efficiency is typically expressed as a "first-law" efficiency, whereas the exergy efficiency of a typical furnace is much lower than the first-law thermal efficiency. In Thermodynamics, the thermal efficiency (\eta_{th} \ is a dimensionless performance measure of a thermal device such as an Internal combustion Exergy efficiency (also known as the second-law efficiency or rational efficiency) computes the efficiency of a process taking the second law of thermodynamics into By comparison, cogeneration has a higher exergy efficiency than is realizable from burning fuel to generate heat directly at a moderate temperature. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both However, as the vast majority of consumers (as well as many government regulators) are unfamiliar with exergy efficiency, Carnot efficiency, and the Second Law of Thermodynamics, the use of first-law efficiencies to rate furnaces is well-entrenched. Exergy efficiency (also known as the second-law efficiency or rational efficiency) computes the efficiency of a process taking the second law of thermodynamics into A heat engine is a physical or theoretical device that converts Thermal energy to mechanical output The second law of Thermodynamics is an expression of the universal law of increasing Entropy, stating that the entropy of an Isolated system which
Modern household furnaces are classified as condensing or non-condensing based on their efficiency in extracting heat from the exhaust gases. Condensation is the change of the physical state of aggregation (or simply state of matter from gaseous phase into liquid phase Furnaces with efficiencies greater than approximately 89% extract so much heat from the exhaust that water vapor in the exhaust condenses; they are referred to as condensing furnaces. General properties of water vapor Evaporation/sublimation Whenever a water molecule leaves a surface it is said to have evaporated A condensing boiler is a water heating device designed to recover Energy normally discharged to the Atmosphere through the flue Such furnaces must be designed to avoid the corrosion that this highly acidic condensate might cause and may need to include a condensate pump to remove the accumulated water. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are A condensate pump is a specific type of Pump used to pump the condensate ( Water) produced in an HVAC (heating or cooling or Refrigeration Condensing furnaces can typically deliver heating savings of 20%-35% assuming the old furnace was in the 60% Annual Fuel Utilization Efficiency (AFUE) range. The annual fuel utilization efficiency ( AFUE; pronounced 'A'-'Few' is a Thermal efficiency measure of combustion equipment like Furnaces Boilers
Heat Distribution
The furnace transfers heat to the living space of the building through an intermediary distribution system. If the distribution is through hot water (or other fluid) or through steam, then the furnace is more commonly termed a boiler. A boiler is a closed vessel in which Water or other Fluid is heated One advantage of a boiler is that the furnace can provide hot water for bathing and washing dishes, rather than requiring a separate water heater. Water heating is a thermodynamic process using an energy source to heat Water above its initial Temperature. One disadvantage to this type of application is when the boiler breaks down, not only do you not have heat, you don't have domestic hot water either.
Air convection heating systems have been in use for over a century, but the older systems relied on a passive air circulation system where the greater density of cooler air caused it to sink into the furnace, and the lesser density of the warmed air caused it to rise in the ductwork, the two forces acting together to drive air circulation in a system termed "gravity-feed; the layout of the ducts and furnace was optimized for short, large ducts and caused the furnace to be referred to as an "octopus" furnace.
By comparison, most modern "warm air" furnaces typically use a fan to circulate air to the rooms of house and pull cooler air back to the furnace for reheating; this is called forced-air heat. A mechanical fan is an electrically powered device used to produce an airflow for the purpose of creature comfort (particularly in the heat ventilation, exhaust A Forced-air or Warm air Heating system is one which uses Air as its Heat transfer medium Because the fan easily overcomes the resistance of the ductwork, the arrangement of ducts can be far more flexible than the octopus of old. Friction is the Force resisting the relative motion of two Surfaces in contact or a surface in contact with a fluid (e In American practice, separate ducts collect cool air to be returned to the furnace. At the furnace, cool air passes into the furnace, usually through an air filter, through the blower, then through the heat exchanger of the furnace, whence it is blown throughout the building. A heat exchanger is a device built for efficient Heat transfer from one medium to another whether the media are separated by a solid wall so that they never mix or the media In Architecture, Construction, Engineering and real estate development the word building may refer to one of the following Any man-made One major advantage of this type of system is that it also enables easy installation of central air conditioning by simply adding a cooling coil at the exhaust of the furnace. The term air conditioning refers to the cooling and dehumidification of indoor air for Thermal comfort.
Air is circulated through ductwork, which may be made of sheet metal or plastic "flex" duct and insulated or uninsulated. Ducts are used in heating ventilation and air conditioning ( HVAC) to deliver and remove air Unless the ducts and plenums have been sealed using mastic or foil duct tape, the ductwork is likely to have a high leakage of conditioned air, possibly into unconditioned spaces. Another cause of wasted energy is the installation of ductwork in unheated areas, such as attics and crawl spaces; or ductwork of air conditioning systems in attics in warm climates.
The following rare but difficult-to-diagnose failure can occur. If the temperature inside the furnace exceeds a maximum threshold, a safety mechanism with a thermostat will shut the furnace down. A thermostat is a device for regulating the Temperature of a System so that the system's temperature is maintained near a desired setpoint A symptom of this failure is that the furnace repeatedly shuts down before the house reaches the desired temperature; this is commonly referred to as the furnace "riding the high limit switch". This condition commonly occurs if the temperature setting of the high limit thermostat is set too close to the normal operating temperature of the furnace. Another situation may occur if a humidifier is incorrectly installed on the furnace and the duct which directs a portion of the humidified air back into the furnace is too large. The solution is to reduce the diameter of the cross-feed tube, or install a baffle that reduces the volume of re-fed air.
Metallurgical furnaces
In metallurgy, several specialised furnaces are used. Metallurgy is a domain of Materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their These include:
- Furnaces used in smelters, including:
- The blast furnace, used to reduce iron ore to pig iron
- Steelmaking furnaces, including:
- Furnaces used to remelt metal in foundries. Chemical reduction, or smelting, is a form of Extractive metallurgy. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux Steelmaking is the second step in producing Steel from Iron ore. Puddling was an Industrial Revolution means of making iron and Steel. A reverberatory furnace is a metallurgical or process Furnace that isolates the material being processed from contact with the Fuel, but not from contact The Bessemer process was the first inexpensive Industrial process for the mass-production of Steel from molten Pig iron. Open hearth furnaces are one of a number of kinds of Furnace where excess carbon and other impurities are burnt out of Pig iron to produce steel. A basic oxygen furnace, also known as an LD converter, is the place within an integrated steel mill where molten iron from the blast furnace is changed into liquid An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. An induction furnace is an electrical Furnace in which the heat is applied by Induction heating of a conductive medium (usually a Metal) in a Crucible A foundry is a Factory which produces Metal Castings from either Ferrous or non-ferrous alloys
- Furnaces used to reheat and heat treat metal for use in:
- Rolling mills, including tinplate works and slitting mills. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. A rolling mill is a Machine or Factory for shaping Metal by passing it between a pair of Work rolls. Tinplate is sheet steel covered with a thin layer of Tin. Before the advent of cheap mild steel the backing metal was iron. The slitting mill was a Watermill for slitting bars of Iron into rods
- Forges. A forge is the workplace of a smith or a Blacksmith. A forge is sometimes referred to as a smithy.
See also
Industrial process furnaces
An industrial furnace or direct fired heater, is an equipment used to provide heat for a process or can serve as reactor which provides heats of reaction. A vacuum furnace is a type of Furnace that can heat materials typically metals to very high temperatures and carry out processes such as Brazing, Sintering Extractive Metallurgy is the practice of extracting Metal from Ore, purifying it and recycling it A flue gas stack is a type of Chimney, a vertical pipe channel or similar structure through which Combustion product gases called Flue gases are exhausted A fire test is a means of determining whether or not Fire protection products meet minimum performance criteria as set out in a Building code or other applicable legislation In Chemical engineering, chemical reactors are vessels designed to contain Chemical reactions The design of a chemical reactor deals with multiple aspects of Furnace designs vary as to its function, heating duty, type of fuel and method of introducing combustion air. Fuel is any material that is burned or altered in order to obtain energy However, most process furnaces have some common features.
Fuel flows into the burner and is burnt with air provided from an air blower. There can be more than one burner in a particular furnace which can be arranged in cells which heat a particular set of tubes. Burners can also be floor mounted, wall mounted or roof mounted depending on design. The flames heat up the tubes, which in turn heat the fluid inside in the first part of the furnace known as the radiant section or firebox. In this chamber where combustion takes place, the heat is transferred mainly by radiation to tubes around the fire in the chamber. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Radiant energy is the Energy of Electromagnetic waves The quantity of radiant energy may be calculated by integrating Radiant flux (or power Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. The heating fluid passes through the tubes and is thus heated to the desired temperature. The gases from the combustion are known as flue gas. Flue gas is Gas that exits to the atmosphere via a Flue, which is a pipe or channel for conveying exhaust gases from a fireplace oven Furnace, Boiler After the flue gas leaves the firebox, most furnace designs include a convection section where more heat is recovered before venting to the atmosphere through the flue gas stack. Convection in the most general terms refers to the movement of molecules within Fluids (i Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five A flue gas stack is a type of Chimney, a vertical pipe channel or similar structure through which Combustion product gases called Flue gases are exhausted (HTF=Heat Transfer Fluid. Industries commonly use their furnaces to heat a secondary fluid with special additives like anti-rust and high heat transfer efficiency. Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air This heated fluid is then circulated round the whole plant to heat exchangers to be used wherever heat is needed instead of directly heating the product line as the product or material may be volatile or prone to cracking at the furnace temperature. In Petroleum geology and Chemistry, cracking is the process whereby complex organic Molecules such as Kerogens or heavy Hydrocarbons )
Radiant section
The radiant section is where the tubes receive almost all its heat by radiation from the flame. Thermal radiation is Electromagnetic radiation emitted from the surface of an object which is due to the object's Temperature. In a vertical, cylindrical furnace, the tubes are vertical. Tubes can be vertical or horizontal, placed along the refractory wall, in the middle, etc. A refractory is a material that retains its strength at high Temperatures ASTM C71 defines refractories as "non-metallic materials having those chemical and physical , or arranged in cells. Studs are used to hold the insulation together and on the wall of the furnace. The term thermal insulation can refer to materials used to reduce the rate of Heat transfer, or the methods and processes used to reduce heat transfer They are placed about 1 ft (300 mm) apart in this picture of the inside of a furnace. The tubes, shown below, which are reddish brown from corrosion, are carbon steel tubes and run the height of the radiant section. Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. The tubes are a distance away from the insulation so radiation can be reflected to the back of the tubes to maintain a uniform tube wall temperature. Tube guides at the top, middle and bottom hold the tubes in place.
Convection section
The convection section is located above the radiant section where it is cooler to recover additional heat. Convection in the most general terms refers to the movement of molecules within Fluids (i Heat transfer takes place by convection here, and the tubes are finned to increase heat transfer. In thermal physics, heat transfer is the passage of Thermal energy from a hot to a colder body The first two tube rows in the bottom of the convection section and at the top of the radiant section is an area of bare tubes (without fins) and are known as the shield section, so named because they are still exposed to plenty of radiation from the firebox and they also act to shield the convection section tubes, which are normally of less resistant material from the high temperatures in the firebox. Radiant energy is the Energy of Electromagnetic waves The quantity of radiant energy may be calculated by integrating Radiant flux (or power The area of the radiant section just before flue gas enters the shield section and into the convection section called the bridgezone. Flue gas is Gas that exits to the atmosphere via a Flue, which is a pipe or channel for conveying exhaust gases from a fireplace oven Furnace, Boiler Crossover is the term used to describe the tube that connects from the convection section outlet to the radiant section inlet. The crossover piping is normally located outside so that the temperature can be monitored and the efficiency of the convection section can be calculated. The sightglass at the top allows personnel to see the flame shape and pattern from above and visually inspect if flame impingement is occurring. Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. Flame impingement happens when the flame touches the tubes and causes small isolated spots of very high temperature.
Burner
The burner in the vertical, cylindrical furnace as above, is located in the floor and fires upward. Some furnaces have side fired burners, eg: train locomotive. The burner tile is made of high temperature refractory and is where the flame is contained in. A tile is a manufactured piece of hard-wearing material such as Ceramic, stone, metal or even Glass. A refractory is a material that retains its strength at high Temperatures ASTM C71 defines refractories as "non-metallic materials having those chemical and physical Air registers located below the burner and at the outlet of the air blower are devices with movable flaps or vanes that control the shape and pattern of the flame, whether it spreads out or even swirls around. Flames should not spread out too much, as this will cause flame impingement. Air registers can be classified as primary, secondary and if applicable, tertiary, depending on when their air is introduced. The primary air register supplies primary air, which is the first to be introduced in the burner. Secondary air is added to supplement primary air. Burners may include a premixer to mix the air and fuel for better combustion before introducing into the burner. Fuel is any material that is burned or altered in order to obtain energy Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Some burners even use steam as premix to preheat the air and create better mixing of the fuel and heated air. The floor of the furnace is mostly made of a different material from that of the wall, typically hard castable refractory to allow technicians to walk on its floor during maintenance.
A furnace can be lit by a small pilot flame or in some older models, matches. A pilot light is a small Gas Flame, usually Natural gas or Liquefied petroleum gas, which is kept alight in order to serve as an ignition source . . Most pilot flames nowadays are lit by an ignition transformer (much like a car's spark plugs). The pilot flame in turn lights up the main flame. The pilot flame uses natural gas while the main flame can use both diesel and natural gas. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum When using liquid fuels, an atomizer is used, otherwise, the liquid fuel will simply pour onto the furnace floor and become a hazard. Using a pilot flame for lighting the furnace increases safety and ease. (compared to using a match)
Sootblower
Sootblowers are found in the convection section. As this section is above the radiant section and air movement is slower because of the fins, soot tends to accumulate here. Soot (ˈsʊt is a general term that refers to the black impure carbon particles resulting from the incomplete combustion of a hydrocarbon Sootblowing is normally done when the efficiency of the convection section is decreased. This can be calculated by looking at the temperature change from the crossover piping and at the convection section exit. Sootblowers utilize flowing media such as water, air or steam to remove deposits from the tubes. This is typically done during maintenance with the air blower turned on. There are several different types of sootblowers used. Wall blowers of the rotary type are mounted on furnace walls protruding between the convection tubes. The lances are connected to a steam source with holes drilled into it at intervals along its length. The term lance has become a catchall for a variety of different Pole weapons based on the Spear. When it is turned on, it rotates and blows the soot off the tubes and out through the stack.
Stack
The flue gas stack is a cylindrical structure at the top of all the heat transfer chambers. A flue gas stack is a type of Chimney, a vertical pipe channel or similar structure through which Combustion product gases called Flue gases are exhausted The breeching directly below it collects the flue gas and brings it up high into the atmosphere where it will not endanger personnel. Flue gas is Gas that exits to the atmosphere via a Flue, which is a pipe or channel for conveying exhaust gases from a fireplace oven Furnace, Boiler Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five
The stack damper contained within works like a butterfly valve and regulates draft (pressure difference between air intake and air exit)in the furnace, which is what pulls the flue gas through the convection section. A damper is a valve or plate that stops or regulates the flow of air inside a duct, Chimney, VAV box, Air handler, or other air handling equipment A butterfly valve is a type of flow control device typically used to regulate a fluid flowing through a section of pipe Stack effect is the movement of air into and out of buildings Chimneys, Flue gas stacks, or other containers and is driven by Buoyancy. Convection in the most general terms refers to the movement of molecules within Fluids (i The stack damper also regulates the heat lost through the stack. As the damper closes, the amount of heat escaping the furnace through the stack decreases, but the pressure or draft in the furnace increases which poses risks to those working around it if there are air leakages in the furnace, the flames can then escape out of the firebox or even explode if the pressure is too great. Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface
Insulation
Insulation is an important part of the furnace because it prevents excessive heat loss. The term thermal insulation can refer to materials used to reduce the rate of Heat transfer, or the methods and processes used to reduce heat transfer Refractory materials such as firebrick, castable refractories and ceramic fibre, are used for insulation. A refractory is a material that retains its strength at high Temperatures ASTM C71 defines refractories as "non-metallic materials having those chemical and physical A fire brick, firebrick, or refractory brick is a block of refractory Ceramic material used in lining Furnaces Kilns A refractory is a material that retains its strength at high Temperatures ASTM C71 defines refractories as "non-metallic materials having those chemical and physical High temperature insulation wool is a material manufactured from alumino silicate glass which is used for thermal insulation in high temperature applications and processes up to 700 The floor of the furnace are normally castable type refractories while those on the walls are nailed or glued in place. Ceramic fibre is commonly used for the roof and wall of the furnace and is graded by its density and then its maximum temperature rating. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different For eg: 8# 2,300°F means 8 lb/ft3 density with a maximum temperature rating of 2,300°F. An example of a castable composition is kastolite.
Outdoor Wood-Fired Boilers
Description
An outdoor wood-fired boiler (OWB) also known as a waterstove or outdoor wood furnace or simply a wood boiler, is a heating technology that has grown in popularity in the Northern United States. OWBs in most cases look like a small shack with metal siding. They are self-contained, and are only connected to the building they heat through underground insulated water pipes. OWBs contain a metal combustion chamber for a wood fire, which is surrounded by a water tank or water jacket. The fire heats the water, which is then circulated through the insulated water pipes into the heated building. Once the hot water from the boiler reaches the building, the heat from the hot water can be transferred to most existing heating systems and the building's hot water supply.
A damper and fan on the boiler interacts with a thermostat inside the building. If the building's temperature falls, the thermostat will trigger the damper to open, letting oxygen enter the combustion chamber, which causes the fire to burn more intensely. The fire will then raise the temperature of the water which increases the heat supplied to the home.
Benefits
OWBs have several benefits that increase their popularity. Their large combustion chamber accommodates more fuel than many other forms of wood heat, decreasing the number of times an owner has to add fuel to the fire. Home insurance may cost more for people who heat with an indoor form of wood heat than with an OWB [1]. Finally, for people with a large supply of free wood and willing to invest the time to prepare the wood and stock the OWB, an OWB can be less expensive than heating with gas, oil, or electricity.
Controversy
OWBs are not without controversy, as their emissions sometimes bother neighbors. Some states and municipalities have banned the devices[2]. They are not currently regulated by the United States Environmental Protection Agency (EPA), unlike other forms of wood heat [3]. (However, recently the EPA has worked with manufacturers to develop a method for manufacturers to identify OWBs that meet a voluntary emissions standard [4]. ) Studies conducted on OWBs suggest that these devices may produce more emissions, most notably particulate matter under 2. Particulates, alternatively referred to as particulate matter (PM or fine particles, are tiny particles of solid or liquid suspended in a gas 5 micrometers (PM2. 5) than other heating technologies, though manufacturers dispute these assessments [5]. Exposure to elevated levels of PM2. 5 has been associated with cardiopulmonary health effects and premature death [6]
As of July 2006, the HPBA, along with many of the major OWB manufactures, have requested users of their products follow the "Outdoor Wood Furnace Best Burn Practices" [7] These guidelines have been set up by the HPBA to help cut down on problems associated with OWBs.
Early in January 2007, the United States Environmental Protection Agency (EPA) initiated a voluntary program [8] for manufacturers of outdoor wood furnaces. The EPA's primary intent is to encourage manufacturers to produce cleaner Outdoor Wood-fired Hydronic Heaters (OWHH) models. The EPA also wants those who buy an OWHH / OWB to buy the cleanest models available, which are those that meet EPA performance verified levels. To participate in this program, manufacturers commit their best efforts to develop cleaner models with goals of distributing their units starting in April 2007. [9]
The EPA now publishes a list of all OWHH / OWB units that pass the new voluntary program. [10] These furances come with the 'orange EPA OWHH tag' to notify the customer of the units particular emission level output.
References
- Gray, W. A. and Muller, R (1974). Engineering calculations in radiative heat transfer, 1st Edition, Pergamon Press Ltd. ISBN 0-08-017786-7 or ISBN 0-08-017787-5.
- Fiveland, W. A. , Crosbie, A. L. , Smith A. M. and Smith, T. F. (Editors) (1991). Fundamentals of radiation heat transfer. American Society of Mechanical Engineers. ISBN 0-7918-0729-0.
- Warring, R. H (1982). Handbook of valves, piping and pipelines, 1st Edition, Gulf Publishing Company. ISBN 0-87201-885-7.
- Dukelow, Samuel G (1985). Improving boiler efficiency, 2nd Edition, Instrument Society of America. ISBN 0-87664-852-9.
- Whitehouse, R. C. (Editor) (1993). The valve and actuator user's manual. Mechanical Engineering Publications. ISBN 0-85298-805-2.
- Davies, Clive (1970). Calculations in furnace technology, 1st Edition, Pergamon Press. ISBN 0080133665.
- Goldstick, R. and Thumann, A (1986). Principles of waste heat recovery. Fairmont Press. ISBN 0-88173-015-7.
- ASHRAE (1992). ASHRAE Handbook. Heating, ventilating and air-conditioning systems and equipment. ASHRAE. ISSN 1078-6066.
- Perry, R. H. and Green, D. W. (Editors) (1997). Perry's Chemical Engineers' Handbook, 7th Edition, McGraw-Hill. Perry's Chemical Engineers' Handbook was first published in 1934 and the most current eighth edition was published in October 2007. ISBN 0-07-049841-5.
- Lieberman, P. and Lieberman, Elizabeth T (2003). Working Guide to Process Equipment, 2nd Edition, McGraw-Hill. ISBN 0-07-139087-1.
See also
- Boiler
- Jetstream furnace
- HVAC
- Flue gas stacks
- Humidifier
- Solar power
- Cremation
- Fan heater
- Geothermal Systems
- Fire test
Notes
External links
A boiler is a closed vessel in which Water or other Fluid is heated Jetstream furnaces (later Tempest wood-burning boilers were an advanced design of wood-fired water heaters conceived by Dr HVAC (pronounced either "H-V-A-C" or occasionally " H-vak " is an Initialism or Acronym that stands for " Heating A flue gas stack is a type of Chimney, a vertical pipe channel or similar structure through which Combustion product gases called Flue gases are exhausted A humidifier is a household Appliance that increases Humidity (moisture in a single room or in the entire home Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life Cremation is the act of reducing a Corpse by burning, generally in a crematorium furnace or crematory fire A fan heater is a heater that works by using a fan to pass air over a Heating element. A geothermal heat pump system is a heating and/or an Air conditioning system that uses the Earth's ability to store heat in the ground and water Thermal A fire test is a means of determining whether or not Fire protection products meet minimum performance criteria as set out in a Building code or other applicable legislationDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic