TERMINOLOGY USED IN HVAC PART-4

Some common difinition used in hvac industry-

REFRIGERANT- A substance which produce a refrigerating effect while expanding or vaporizing.

REFRIGERANT CONTROL- A divice used to meter the amount of refrigerant to an evaporator. It also services as a dividing point betweem the high and low pressure side of the system.

REFRIGERANT DISTRIBUTOR- A divice which meters equal quantities of refrigerant to independent circuits in the evaporator coil.

REFRIGERANT MIGRATION- The movement of refrigerant through the system to the compressor crankcase during the off-cycle, caused by its attraction to coil.

REFRIGERANT VELOCITY- The rate at which refrigerant is moving at a given point in a system, usually given in a feet per minute (FPM).

REFRIGERATION- The transfer of heat from a place where it is not wanted to a place where its presence is not desirable.

REFRIGERATION EFFECT- The amount of heat a given quantities of refrigerant will absorb in changing from a liquid to a vapour at a given evaporating pressure.

RELATIVE HUMIDITY- The percentage of water vapour present in a  given quantity air compared to the amount it can hold at its temperature.

RISER- A virticle tube or pipe which carries refrigerant in form from lower to higher level.

SATURATED VAPOUR- Vapour in contact with a liquid.

SATURATION- A condition of stable equilibirium of a vapour and a liquid. SENSIBLE HEAT  that can be measured or felt. Sensible heat always causes a temperature rise.

PARTIAL PRESSURE- The pressure exerted by any individual gas in a mixture.

PITCH- The slope of a pipe line for the purpose of improving drainage.

PRESSURE DROP-  The decreases in pressure due to friction of a liquid or vapour as it passes through a tube or duct or/and lift.

RADIATION- The transfer of heat without an intervening medium. It is absorbed or contact with a solid surface.

RECEIVER- A vessel for holding refrigerant liquefied by the condenser.