The outdoor wood boiler is a variant of the classic wood stove adapted for set-up outdoors while still transferring the heat to interior buildings.
The outdoor wood boiler is a variant of the classic wood stove adapted for set-up outdoors while still transferring the heat to interior buildings.
The outdoor wood boiler is a variant on the indoor wood, oil or gas boiler. An outdoor wood boiler or outdoor wood stove is a unit about 4-6 feet wide and around 10 feet long. It is made up of four main parts- the firebox, which can be either round or square, the water jacket, the heat exchanger, and the weather proof housing. The fire box ranges from 2 to 5 feet long and can be as tall as 4 feet. The firebox and heat exchanger are surrounded by water or a glycol-water solution, which absorb heat from the burning wood. The heated water is generally circulated through insulated underground lines to a heating load, where the heat can be transferred from the water to various heat emitters. [1]
Standard outdoor wood boilers heat the firebox and the smoke goes out the exhaust straight. If not run hot enough, the exhaust gas will be thick and black, and the resulting ash will not be fully rendered. [2] While functional, these models take more work and are far less efficient [3] than some newer more efficient models.
Some newer outdoor wood boilers have a catalytic converter installed, to allow for a more efficient burn and treatment of the exhaust before it leaves the unit. There is a considerable difference in cost between these and standard units. These are far less popular than gasification outdoor wood boilers. [2] [4]
Gasifier wood boilers use secondary combustion air to burn additional wood gases. The most sophisticated systems use computer controls to direct air at different stages of the burn process at variable volume.
High efficiency outdoor wood boilers use down draft gasification must meet strict EPA Phase 2 Certification. Outdoor wood gasification boilers can burn between 30% - 50% less fuel than its traditional counterpart.
Outdoor wood boilers are a topic of environmental controversy. [5] An improperly used or built outdoor wood boiler can produce wood smoke with excessive unburned particulate matter, but when properly burned, studies show that burning wood is still one of the most environmentally friendly heating options. In 2007, EPA began a voluntary program to encourage manufacturers to reduce particulate levels. In 2015, the U.S. EPA updated its clean air standards for residential wood heaters, this is a mandatory standard for sales in the United States. The revised regulations apply only to new products and will not affect existing wood heaters. At this point, the only boilers that pass these emission controls are gasification models. [6]
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR.
A boiler is a closed vessel in which fluid is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation.
Fluidized bed combustion (FBC) is a combustion technology used to burn solid fuels.
Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated to steam have many uses.
A stove or range is a device that generates heat inside or on top of the device, for local heating or cooking. Stoves can be powered with many fuels, such as electricity, natural gas, gasoline, wood, and coal.
Wood fuel is a fuel such as firewood, charcoal, chips, sheets, pellets, and sawdust. The particular form used depends upon factors such as source, quantity, quality and application. In many areas, wood is the most easily available form of fuel, requiring no tools in the case of picking up dead wood, or few tools, although as in any industry, specialized tools, such as skidders and hydraulic wood splitters, have been developed to mechanize production. Sawmill waste and construction industry by-products also include various forms of lumber tailings.
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning systems, which can both cool and warm interior spaces.
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design.
A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam turbine connected to an electrical generator. The low-pressure exhaust from the turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate more high pressure steam. This is known as a Rankine cycle.
Pellet fuels are a type of solid fuel made from compressed organic material. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, and untreated lumber. Wood pellets are the most common type of pellet fuel and are generally made from compacted sawdust and related industrial wastes from the milling of lumber, manufacture of wood products and furniture, and construction. Other industrial waste sources include empty fruit bunches, palm kernel shells, coconut shells, and tree tops and branches discarded during logging operations. So-called "black pellets" are made of biomass, refined to resemble hard coal and were developed to be used in existing coal-fired power plants. Pellets are categorized by their heating value, moisture and ash content, and dimensions. They can be used as fuels for power generation, commercial or residential heating, and cooking.
A pellet stove is a stove that burns compressed wood or biomass pellets to create a source of heat for residential and sometimes industrial spaces. By steadily feeding fuel from a storage container (hopper) into a burn pot area, it produces a constant flame that requires little to no physical adjustments. Today's central heating systems operated with wood pellets as a renewable energy source can reach an efficiency factor of more than 90%.
Electric heating is a process in which electrical energy is converted directly to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.
A masonry heater is a device for warming an interior space through radiant heating, by capturing the heat from periodic burning of fuel, and then radiating the heat at a fairly constant temperature for a long period. Masonry heaters covered in tile are called cocklestoves. The technology has existed in different forms, from back into the Neoglacial and Neolithic periods. Archaeological digs have revealed excavations of ancient inhabitants utilizing hot smoke from fires in their subterranean dwellings, to radiate into the living spaces. These early forms have evolved into modern systems.
Renewable heat is an application of renewable energy referring to the generation of heat from renewable sources; for example, feeding radiators with water warmed by focused solar radiation rather than by a fossil fuel boiler. Renewable heat technologies include renewable biofuels, solar heating, geothermal heating, heat pumps and heat exchangers. Insulation is almost always an important factor in how renewable heating is implemented.
Underfloor heating and cooling is a form of central heating and cooling that achieves indoor climate control for thermal comfort using hydronic or electrical heating elements embedded in a floor. Heating is achieved by conduction, radiation and convection. Use of underfloor heating dates back to the Neoglacial and Neolithic periods.
Jetstream furnaces, were an advanced design of wood-fired water heaters conceived by Dr. Richard Hill of the University of Maine in Orono, Maine, USA. The design heated a house to prove the theory, then, with government funding, became a commercial product.
An oil heater, also known as an oil-filled heater, oil-filled radiator, or column heater, is a common form of convection heater used in domestic heating. Although filled with oil, it is electrically heated and does not involve burning any oil fuel; the oil is used as a heat reservoir (buffer).
An electric boiler is a device that uses electrical energy to boil water. It is different than a gas or oil boiler because an electric boiler uses electricity instead of fossil fuels.
A wood-burning stove is a heating or cooking appliance capable of burning wood fuel, often called solid fuel, and wood-derived biomass fuel, such as sawdust bricks. Generally the appliance consists of a solid metal closed firebox, often lined by fire brick, and one or more air controls. The first wood-burning stove was patented in Strasbourg in 1557. This was two centuries before the Industrial Revolution, so iron was still prohibitively expensive. The first wood-burning stoves were high-end consumer items and only gradually became used widely.
A rocket mass heater (RMH), also known as rocket stove mass heater, is a form of slow-release radiant heating system, designed to primarily heat people and secondarily to warm areas in line of sight around it. Variations of RMH can also be extended for the functions of cooking, heating water, and producing warm air for distribution.