Glossary


A | B |C |D |E |F |G |H |I |J |K |L |M |N |O |P |Q |R |S |T |U |V |W |X |Y |Z


Air handler: An appliance that moves air across heating or cooling coils using a blower. Heating coils are also called warm air coils; cooling coils are also called direct expansion coils. High efficiency air handlers also use variable speed electronically commutated motors (ECM).

Air Box: Provides a PVC connection for outside air for combustion and ultra quiet operation; the air box encloses the burner.


Brookhaven National Laboratory: Located on Long Island in New York state, BNL is one of ten of the Department of Energy’s national laboratories . Find out more about heating system studies or the National Laboratory system.

BTU: British Thermal Unit or the amount of energy required to change the temperature of one pound of water by one degree Fahrenheit.


Direct Fired Water Heater: A water tank where the water is typically heated with a natural gas, propane, or oil burner. Conventional direct fired water heaters have central flues which increase idle losses and reduce overall efficiency. Compare to Indirect Water Heater.

Draft Regulator or Draft Hood: An older technology which allows a chimney to stabilize the fuel burning process by continual flow of air from inside the building up the chimney. Although this may reduce flow through the boiler, furnace or water heater, studies indicate these impose a large heat loss on the building.


Energy Converter: Highly efficient, low mass hydronic heat exchanger.

Energy Star: Energy Star is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy designed to help save money and protect the environment through energy efficient products and practices.

Expansion Tank: A tank which usually has a pressurized air bladder that accommodates the expansion of water as it heats up. These are always required in hydronic or boiler systems, and are sometimes required in potable water systems.



Heat exchanger: A device that transfers heat from one fluid to another across a solid surface so the fluids are separated and do not mix. Examples include a boiler heat exchanger that transfers heat from the products of combustion to the hydronic fluid, and a plate heat exchanger which transfers heat from the hydronic fluid to a hot water storage tank using a highly efficient “counterflow” thermodynamic design.

High Efficiency Boiler: High efficiency combination boilers are heat and hot water boilers with annual fuel utilization efficiency (AFUE) ratings of 86 or greater and idle losses as defined by Brookhaven National Laboratories of less than 0.7%. Because boilers are idle much of the day, even moderate idling losses can add up to much higher fuel bills. Energy Kinetics combination boilers score as high as 96.8 AFUE, and have idle loss as low as 0.15%, saving up to 40% over other heat and hot boilers. Energy Kinetics high efficiency boilers use less fuel while saving you money. A high efficiency boiler from Energy Kinetics can provide you with lower energy costs, virtually endless hot showers and a more comfortable home for years of trouble-free operation.1

High Performance Home: A home that employs a variety of proven energy-efficient features that contribute to improved home quality and homeowner comfort, and to lower energy demand and reduced air pollution.

Hybrid Energy Recovery®: The process System 2000 uses to anticipate the end of a heat or hot water requirement and to recover the heat left in the boiler so this energy is not wasted.

HydroAir: A system that transfers heat from the hydronic (boiler) system to a warm air system through the use of an air handler and a warm air coil. A hydroair system is at the heart of Energy Kinetics Comfort Air System.

Hydronic: A type of heating or cooling system that transfers heat through the flow of water in a closed system of pipes.

Idle Loss: The losses associated with heating equipment when there is not an active demand for heat or hot water. Idle loss has a very large impact on annual performance and is virtually ignored in AFUE ratings. Idle loss and AFUE may be combined to much more accurately estimate fuel consumption and savings. Idle loss is sometimes referred to as standby loss.

Indirect Water Heater: A water storage tank where the water is heated by a boiler through a coil within the tank or through an external heat exchanger.


Kinetic: The energy, motion, and forces associated with material bodies. Kinetic energy is the energy (which may relate to heat) associated with material bodies.

kWh: A Kilowatt Hour is the amount of energy to operate 1000 watts for 1 hour. This is about 3,413 BTUs. See energy content from other fuels.

Lawrence Berkeley National Laboratory: Located in Berkeley, California, LBNL is one of ten of the Department of Energy’s national laboratories. Find out more about the National Laboratory system.


National Laboratory: The Department of Energy has a laboratory system which is the most comprehensive research system of its kind in the world and supports the missions of its science programs. Find out more about heating system studies or the National Laboratory system.


Outdoor Reset Control: see Temperature reset control

Pressure Reducing Valve: A pressure control valve used to regulate outlet pressure. Also called a boiler feeder or boiler feed valve, these typically drop domestic water supply pressure (usually over 40 psi) to fill a hydronic system (usually at 12 to 15 psi).


Radiant Heat: The transfer of heat from a heated surface such as a floor, ceiling or wall. In hydronic or boiler systems, radiant tubing is often installed under floor throughout the entire floor area. Because such a large area is heated, room thermostats may satisfied with lower supply water temperatures than conventional baseboard and cast iron radiation. Other common radiant heating systems include gas and oil fired overhead radiant heaters and under floor electric systems.

Sidewall Power Venting: Allows system to be vented without a chimney. Low cost venting alternative.

Steady State Efficiency: The efficiency of a boiler or furnace during continuous operation; this is usually the highest efficiency for the appliance. This is very close to the AFUE rating and is the ratio of the energy in the fuel consumed to the energy delivered out of the boiler or furnace supply. Combined with idle loss, real efficiency may be much more accurately determined.

System Manager: Runs the burner only when you need heat and delivers that heat only where needed. Also provides Hybrid Energy Recovery.


Temperature Reset Control: An automatic means for adjusting the temperature of the water supplied by the boiler such that an incremental change in inferred heat load produces a corresponding incremental change in supply water temperature. Studies show temperature reset controls may save 5% to 15%, but need trial and error adjustments over the course of a heating season; better insulated boilers with lower idle loss realize a smaller efficiency benefit from temperature reset than high idle loss boilers. By comparison, using proven Hybrid Energy Recovery, System 2000 automatically adapts to heating loads without trial and error adjustments and has greater proven savings.

Therm: A measure of energy equal to 100,000 BTU. See energy content from other fuels.



Warm air coil: A heat exchanger similar to a car radiator coil that transfers heat from a hydronic system (boiler water) to warm air in duct work. These are often used in air handlers.