» Heating Basics » Upgrading Old Equipment » Glossary of Terms	Glossary of Terms A.F.U.E.: Annual Fuel Utilization Efficiency represents the percentage of fuel that is converted into usable heating energy - the balance is vented through your chimney or other venting systems. It is an industry agreed upon standard. All furnaces and brands are tested the same way to provide "apples to apples" comparisons. Air Conditioner - a device used to decrease the temperature and humidity of air, which moves through it. Typical air conditioners include central air conditioning which utilizes existing forced air ductwork and “Ductless Splits”. Anode Rod - a sacrificial metal used to protect against corrosion in a hot water heater. Baseboard Heating - heating elements located around the perimeter of a room, used to warm room air by transferring the heat from the hot water circulating through them. Blower – an air handling device used with a furnace to circulate air through a network of ducts. Boiler: A heating appliance that heats water to a pre-set temperature and feeds it to a circulator, which transfers the water to radiant heating units including some or all of cast iron radiators, slim baseboard radiators, under floor tubing or wall panels. Some boilers produce steam for heating purposes. B.T.U.: British Thermal Units are the standard efficiency comparison between heating fuels. One BTU is the amount of heating energy that will raise one pound of water one degree Fahrenheit. B.T.U./Hr.: British Thermal Units Per Hour. Used to express capacities of furnaces and boilers. Burner - a device which supplies a mixture of air and fuel to the combustion area. Cast Iron - a durable metal with an exceptional capability to hold and transfer heat. Chimney Liner: A clay-tile or metal liner that is inserted into a chimney. Chimney Venting - a vertical vent used to transfer products of combustion from a furnace or boiler to the outdoors. Combustion - the process of converting fuel into heat. This requires oxygen. Combustion Air: An air supply brought into the furnace's combustion chamber - supplied from within the basement, or from outdoors. Combustion air is necessary to burn fuel. Controls: Devices such as a thermostat that regulate a heating or cooling system. Convection: The transfer of heat through a moving gas (air) and a surface, or the transfer of heat from one point to another within a gas. In hydronic heating, cool air falls to the floor where it is heated by metal fins in a baseboard radiator and then rises to transfer heat to the environment through natural convection. Convective Heat: the natural circulation of air across a heat source to heat the air. Degree Days: A system by which heating oil dealers measure and record the daily temperature. This information is compared to what they know about your heating system to ensure automatic delivery before your system uses all of the oil in the storage tank. Direct Venting: A process in which the products of combustion are vented to the outdoors via sidewall venting, (without the use of a chimney). Direct Vent - a furnace or boiler design where all the air for combustion is taken from the outdoors and all exhaust products are released to the outdoors, also known as sealed combustion. Direct Vent is also known as balanced flue venting in oil furnaces and boilers. Distribution System: The component of a heating or cooling system that delivers warmed or cooled air, or warmed water, to the living space. Draft Hood - a device that prevents a backdraft from entering the heating unit or excessive chimney draw from affecting the operation of the boiler or furnace. Ductless Split A/C System - A system that cools and dehumidifies air without the use of conventional duct work. The equipment location is split, with the condenser and heat pump outside of the home and the air handler and controls inside. Efficiency Rating - the ratio of heat actually generated versus the amount of heat Theoretically possible from the amount of fuel inputted. Flame Retention Burner: A modern oil burner which retains the flame near the mouth of the burner, for improved efficiency and operational savings. Flue: An enclosed passage that is designed to convey hot flue gases. (Also known as a breech). Flue Gases: The gases (eg. carbon dioxide, water vapour and nitrogen) that are formed when the fuel oil, natural gas, or propane is burned with the air. (Products of combustion are technically all of the flue gases less the nitrogen that was present before combustion). Forced Air: A distribution system in which a fan circulates air from the heating or cooling unit to the rooms through a network of supply air and return air ducts. Furnace: A heating appliance that warms air around a heat exchanger. The air is conveyed by fan, into a central duct system to distribute warm air to all areas of the home or building. Heat Exchanger: A structure that transfers heat from the hot combustion gases inside the furnace heat exchanger to the circulating room air flowing across the exterior of the heat exchanger. Heat Loss: Term used for all areas of your home where heated air may escape due to construction styles, age of house, windows, weather-stripping, etc. All homes will experience some level of heat loss. Heat Loss Calculation: This is the means by which a heating contractor will determine the required capacity of a furnace or boiler to adequately heat the home (or building). Heat Recovery Ventilator (HRV): A device used in central ventilation systems to reduce the amount of heat that is lost as household air is replaced with outside air. As fresh air enters the house, it is warmed as it passes through a heat exchanger, heated by the warm outgoing air stream. Heat Transfer: the transmission of heat from the source (flame) to air or water. Heating Capacity: the amount of usable heat produced by a heating unit. High-boy: a term used to describe a furnace which has a small "footprint" but is tall. The blower is under the heat exchanger. This is also known as an upflow furnace. Hot Water Boiler: a heating unit that uses water circulated throughout the home in a system of baseboard heating units, radiators, and/or in-floor radiant tubing. Hot Water Heater: a unit with its own energy source that generates and stores hot water. Hydronics: Hydronics, or heating with water, consists of a compact boiler (fired by any fuel) that heats water, which is distributed to a network of slim baseboard, panel or space radiators, or under floor tubing by a circulator. This term also applies to the science of heating (or cooling) with water. Indirect Hot Water Storage Tank: a unit that works in conjunction with a boiler to generate and store domestic hot water, it does not require its own energy source. In-floor Radiant Tubing: tubing, typically plastic or rubber, used in conjunction with heated boiler water to heat floors. Low-boy: a term used to describe a furnace which has a low profile. The blower is located on the same level plane as the heat exchanger. This furnace style has both the return air plenum and the supply air plenum on the top of the furnace. This furnace style is sometimes called a console style furnace. Low Water Cut-off: a device used to shut down a boiler in the event that a low water condition exists. This is required whenever radiators are located at a lower level than the boiler. Some jurisdictions require them on all boiler installations. Natural Gas: any gas found in the earth (e.g. methane gas) as opposed to gases which are manufactured. Nozzle: A burner component that atomizes, meters and patterns fuel oil into the heat exchanger / fire-pot. Oil Heating: the production of heat by burning oil. Propane: a manufactured gas typically used for cooking or heating. This is also known as L.P. gas. (liquid petroleum). Push Nipples: machined metal sleeves used to join adjacent sections of a boiler. Radiant Floor Heating: Under floor heat is provided by flexible, long-lasting tubing. The continuous tubing can be placed under any flooring, and circulated hot water provides invisible heat anywhere in the home, swimming pool or driveway. Radiant Heating: the method of heating the walls, floors or ceilings in order to transfer heat to the occupants of a room. Radiator: a heating element, typically metal, used in conjunction with water or steam to give off heat. Retrofit: Replacement of one or more components of an existing system. Safety Shut-off Device: any device used to shut down a heating appliance in the event an unsafe condition exists. Seasonal Efficiency: A performance rating that considers the heat actually delivered to the living space, the total energy available in the fuel consumed, and the impact the equipment itself has on the total heating load through an entire heating season. S.E.E.R.: Seasonal Energy Efficiency Rating. The standards by which equipment is measured. The higher the S.E.E.R., the more efficient the equipment (especially air conditioning). Sealed Combustion: a furnace or boiler design where all the air for combustion is taken from the outside atmosphere and all exhaust products are released to the outside atmosphere, also known as direct vent. Steam Boiler: a heating unit designed to heat by boiling water, producing steam, and circulating it to radiators or steam baseboard units throughout the home. Stack Damper: a device installed in the venting system that will automatically close when the appliance shuts down. This device is used to reduce the amount of warm indoor air being drawn up the chimney between heating cycles. Supply Tapping: opening in a boiler by which hot water enters the heating system. Setback Thermostat: A programmable thermostat with a built-in timer. You can adjust it to vary household temperature automatically. Tankless Heater: a copper coil submerged into the heated boiler water used to transfer heat to domestic water. Venting: An opening for combustion gases to exit the house. Can be a chimney or a vent through the wall of the house. Includes all parts of the venting system - vent connector, chimney, etc. Zone Control: A heating control system in which the space to be heated is divided into zones and each zone is controlled by a separate thermostat.