Glossary

A comprehensive term used in a boiler-unit heat balance to account for the conduction, radiation, and convection heat losses from the boiler to the ambient air.

A method of measuring air infiltration by using a radioactive tracer gas, measuring the concentration by the radioactive emissions. Isotopes of the noble gases are preferred. 4lAr, 85Kr, 133Xe are beta emitters. Radon (Rn or 222Em) is an alpha emitter.
Detector: Geiger-Mullen tube, scintillation counter.

(Rn or 222Em) noble gas formed in the decay chains of isotopes of uranium and thorium. Decays by alpha and gamma emission to 218Po with a half life of 3.823 days. Daughter products unstable. Commonly occurring indoor pollutant deriving from trace quantities of heavy elements in concrete, building stone and the water supply. It can also occur in natural gas. Considered for use as a tracer gas measuring air infiltration.

The horizontal distance in feet from the diffuser to a point where the terminal velocity of 50 feet per minute occurs.

Random access memory.

The limits within which a device or circuit operates or the distance over which a transmitter operates reliably.

A method of measuring ventilation rate whereby a quantity of tracer gas is released and the decrease in concentration measured as a function of time. (also known as the decay method and the tracer dilution method.)

The process of calculating financial ratios for your business in order to determine trends and to compare its performance with that of other businesses in the same industry.

The starting material(s) in a chemical process that is converted into final product(s) and sometimes process intermediate(s).

A chemical transformation or change brought about by the interaction of two substances.

Represent invoices that you have billed but have not been paid. Also known as accounts receivable, they can be listed as current assets.

In refrigeration, a type of compressor which compresses refrigerant vapour by moving a piston up and down in a cylinder.

Air removed from the conditioned space and intended for re-use as supply air.

The reintroduction of part of the flowing fluid to repeat the cycle of circulation.

The processing of fuels or materials to save energy or material values before treatment and disposal in management hierarchy.

Removal of oxygen from a chemical compound.

Specified conditions of pressure, temperature and relative humidity for air.

The amount of sound wave energy (sound) that is rebounded from a surface. Hard non-porous surfaces reflect more sound than soft porous surfaces. Some sound reflection can enhance the quality of the signal of speech and music.

In incineration, a class of materials of construction designed to resist extreme operating conditions (e.g., brick for high-temperature resistance, etc).

The fluid used for heat transfer in a refrigerating system, which absorbs heat at a low temperature and a low pressure of the fluid and rejects heat at a higher temperature and a higher pressure of fluid, usually involving changes of state of the fluid.

A coil placed after the cooling coil, used to raise the air temperature. Process of raising the cooled air temperature.

In an air conditioning system, the final step in treatment, in the event the temperature is too low.

A device has two separate circuits, it is constructed so that a small current in one of the circuits controls a large current in the other circuit. A motor starting relay opens or closes the starting circuit under predetermined electrical conditions in the main circuit (run winding).

(1) Any accidental or unintentional spill, leak, emission or discharge of a material or untreated waste.

(2) Any permitted emission to air, discharge to water, or placement on land of treated waste residuals.

Air supplied to a space to replace exhausted air.

The time during which a substance introduced into the air (or other medium) remains in place before it is transformed into something else.

The duration at which the waste contents of an incinerator are maintained at optimal temperature to ensure maximum destruction of POHCs and minimal formation of PICs.

(1) Remnants of a hazardous waste left after treatment which is assumed under some circumstances to still be hazardous unless proven otherwise.

(2) A process intermediate that may be subject to energy or material recovery before waste treatment.

Impediment to gas flow, such as pressure drop or draft loss through a dust collector. Usually measured in inches of water column.

A device that resists the flow of electrical current for the purpose of operation, protection or control. There are two types of resistors-fixed and variable. A fixed resistor has a fixed value of ohms while a variable resistor is adjustable.

The emphasis of sound at a particular frequency.

Those particles in air which penetrate into and are deposited in the non-ciliated portion of the lung.

Particulates in the size range that permits them to penetrate deep into the lungs upon inhalation.

Sound after it is ended at the source will continue to reflect off surfaces until the sound wave loses energy by absorption to eventually die out. The persistence of sound in an enclosed space after the sound source has stopped. In a reverberation room, it is characterized by the decay or dying away the sound.

The time taken for sound to decay 60 dB to 1/1,000,000 of its original sound level after the sound source has stopped. Sound after it has ended will continue to reflect off surfaces until the wave loses enough energy by absorption to eventually die out. Reverberation time is the basic acoustical property of a room, which depends only on its dimensions and the absorptive properties of its surfaces and contents. Reverberation has an important impact on speech intelligibility.

Dimensionless ratio which gives an estimate of the relative importance of viscous and non-viscous forces.

A vertical pipe or duct.

Quantification of effect and exposure defining the upper bond of risk. Actual risk may be less than estimated risk due to uncertainties and conservative assumptions.

Selection of technology or policy controlling risk.

A first stage of some incinerators designed to rotate and burn a wide variety of feeds and varying feed rates of solid and hazardous wastes, and supplemental fuels as needed.

The direction in which a shaft turns is either clockwise (CW) or counterclockwise (CCW). When specifying rotation, also state if viewed from the shaft end or the opposite shaft end of the motor.

The rotating part of the fan which includes the propeller assembly.

Revolutions Per Minute is the number of times per minute that the fan turns. High RPM's don't always mean a lot of air is being moved.

Air flow is a combination of fan speed, blade pitch and other factors. Revolutions per minute, the measurement of fan blade speed.

Resistance temperature detector.