HVAC Terms 空调专业用语.doc

HVAC Terms ABSOLUTE HUMIDITY The weight of water vapor in a given amount of air. Grains per cubic foot or lbs water per cubic foot air ABSOLUTE PRESSURE Pressure measured with a base of zero. ABSOLUTE TEMPERATURE A temperature scale expressed in degrees F0 or C0 using absolute zero as a base. Referred to as the Rankin or Kelvin scale. ABSOLUTE ZERO The temperature at which molecular activity theoretically ceases. -456.69 F0 or -273.16 C0 AIR CONDITIONING The process of controlling the temperature, humidity, cleanliness and distribution of the air. AIRFLOW The distribution or movement of air. AIR HANDLING UNIT (AHU) Equipment with a heating element and/or cooling coil and other components in a cabinet or casing. AIR BALANCING Adjusting an air conditioning system so that the right amount of air is delivered to the right places in your home in order to achieve the right heating or cooling effect. AIR BALANCE TEST A test used to measure airflow across a tower or air handler system. AIR, STANDARD CONDITIONS Conditions at which BTU ratings for summer air conditioning equipment is rated. 95 F0 dry bulb, 75 F0wet bulb at the condenser inlet and 80 F0 dry bulb, 67 F0 wet bulb at the evaporator inlet. AMP The practical meter-kilogram-second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm. AMBIENT Refers to the temperature surrounding a body or unit under test. ARI Air Conditioning and Refrigeration Institute ATMOSPHERIC PRESSURE The weight of a 1 square inch column of the earths atmosphere. At sea level this pressure is 14.696 pounds per square inch. BIMETAL Two metals with different rates of expansion fastened together. When heated or cooled they will warp and can be made to open or close a switch or valve. BOILING POINT The temperature at which the addition of any heat will begin a change of state from a liquid to a vapor. BRITISH THERMAL UNIT (BTU) Th