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AIR CONDITIONING #2
ABC'S OF AIRCONDITIONING
Term | Definition |
---|---|
WHAT IS AIR CONDITIONING? | 1) The process of treating the air, so as to control Simultaneously, its temperature, humidity, cleanliness,and distribution to meet the requirements of the conditioned space. |
WHAT ARE 4 CONDITIONS THAT DIRECTLY AFFECT THE BODY'S COMFORT IN THE CONDITIONED SPACE? | a) Temperature b) Relative Humidity c) Air Cleanliness d) Air Distribution or Circulation |
THE THREE WAYS THAT THE BODY REJECTS HEAT ARE? | 1) Convection- Through air flow. 2) Radiation- Through the use of waveform energy. 3) Evaporation- Through normal perspiration and sweat. Normally the body gives off heat by all three ways at the same time. |
WHAT IS RELATIVE HUMIDITY? | 1) A comparison of the actual moisture in the air, to the amount of moisture that the air can hold @ any given temperature. 2) It is expressed as a percentage. 3) The higher the RH= less comfortable. The lower the RH= more comfortable it feels. |
WHAT ARE THE 2 TYPES OF LOADS? | 1) Cooling Load: Condition where the Conditioned Space has too much heat. 2) Heating Load: Condition where the Conditioned Space has too little heat. |
WHAT IS PRESSURE | 1) Pressure is measured in force/unit area....lbs/in^2...PSI 2) Pressures above 14.7 psi is measured in psi Pressures below 14.7 psi is measured in (in.HG)(mercury), or inches of vacuum. (in.Vac) 3) Pressure determines the boiling point of a liquid. |
WHAT IS A PERFECT VACUUM? | 30 in.Vac is a perfect vacuum. |
WHAT DIRECTION IS THE FORCE OF SOLIDS | Downward |
WHAT DIRECTION IS THE FORCE OF LIQUIDS? | Downward and Sidewards |
WHAT DIRECTION IS THE FORCE OF VAPORS OR GAS? | Exerts pressure in all directions |
HOW DO YOU CONVERT GAUGE PRESSURES (PSIG) TO ABSOLUTE PRESSURES (PSIA)? | Must add 14.7 psi to the gauge pressure. |
WHAT ARE TWO CLASSIFICATIONS OF AN AIR DISTRIBUTION SYSTEM? | 1) RETURN AIR: CONDITIONED SPACE TO AIR CONDITIONING UNIT 2) SUPPLY AIR: TREATED AIR GOING TO CONDITIONED SPACE; DESIGNED TO RETURN AT 60° . |
WHAT IS DEW POINT TEMPERATURE? | THE TEMPERATURE AT WHICH WATER VAPOR (MOISTURE) CONDENSES AND SEPARATES FROM THE AIR. |
WHAT ARE THE TWO OPERATING PRINCIPLES OF A REFRIGERATION SYSTEM? | 1) A LIQUID ABSORBS A LARGE QUANTITY OF HEAT (IN BTUS) WHEN IT EVAPORATES INTO A VAPOR. 2) A VAPOR GIVES UP (LOSES) A LARGE QUANTITY OF HEAT (IN BTUS) WHEN IT CONDENSES INTO A LIQUID. |
WHAT ARE 4 BASIC COMPONENTS OF AN AIR CONDITIONER? | 1) COMPRESSOR 2) CONDENSER 3) METERING DEVICE 4) EVAPORATOR |
WHAT DOES THE COMPRESSOR DO? | A DEVICE THAT CHANGES A LOW PRESSURE AND COLD TEMPERATURE VAPOR INTO A HIGHER PRESSURE AND HIGH TEMPERATURE VAPOR. THE RISE IS DUE TO THE HEAT OF THE COMPRESSOR PROCESS TURNS COLD VAPOR TO HOT GAS |
WHAT DOES THE CONDENSER DO? | A DEVICE USED TO REJECT HEAT FROM THE REFRIGERATION SYSTEM |
WHAT DOES A METERING DEVICE DO? | 1) USED TO CONTROL THE FLOW OF REFRIGERANT TO THE EVAPORATOR. 2) IT HAS A SMALL ORIFICE, THROUGH WHICH LIQUID IS FORCED, CAUSING THE REFRIGERANT TO FLASH, AND DROPS THE PRESSURE AND TEMPERATURE. 3) CHANGES A HOT LIQUID TO A COLD LIQUID / VAPOR MIX |
WHAT DOES THE EVAPORATOR DO? | A DEVICE USED TO ABSORB HEAT INTO THE REFRIGERATION SYSTEM. IT IS DESIGNED TO LOWER THE AIR TEMPERATURE AND MOISTURE FROM THE AIR |