LS1 - Analysis of Air-Conditioning Processes

Thermalfluids Lab -MEC 554/ LS 1/SHAH Rev. 01-2009

UNIVERSITI TEKNOLOGI MARA FACULTY OF MECHANICAL ENGINEERING ________________________________________________________________________ Program : Bachelor Of Engineering ( Hons ) Mechanical Course : Thermodynamics Lab Code : MEC 554 ________________________________________________________________________ LAB SHEET NO:

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HEATING VENTILATION AND COOLING LABORATORY SHEET (HVAC) TITLE : Analysis Of Air-conditioning Processes 1. INTRODUCTION Air-conditioning is a process of treating air for the comfort requirements of the occupants in the conditioned space. The properties of air can be modified by undergoing certain thermodynamic processes. The most basic of processes involved in an air-conditioning system are simple heating, steam humidification, simple cooling and dehumidification. 2. OBJECTIVE To observe and understand the changes in air properties as it is treated in a basic air-conditioning unit. 3. EQUIPMENT Computer Linked Air Conditioning Laboratory Unit ( P.A. Hilton ) 4. EXPERIMENTAL Start the unit by having the suction fan running and the screen displaying the master Menu. Programme 1 shows the process data displayed on a schematic layout of the system. Programme 2 displays the properties of the treated air on the psychrometric chart. a) No Process – print the data and psychrometric chart to read the initial properties of the air as it enters the air-conditioning unit. b) Sensible Heating – I. Switch on 1 kW pre-heater and allow 5 minute. Print the data and psychrometric chart. II. Then, switch on the 0.5 kW re-heater and allow 5 minute. Print the data and psychrometric chart. III. For this process, calculate the temperature rise of the air at the exit. c) Steam Humidification – Switch all water heaters to boil the water. When steam is produced, switch only 3 kW of heat to maintain the steam and allow 5 minute. Print the data and psychrometric chart. Then, calculate the amount of steam introduced, the change in relative humidity, and the corresponding rise of temperature. d) Cooling and Dehumidification – Switch on the compressor of the refrigeration system. Cool the air until 18°C to 20°C (stable temperature), when temperature stable allow 5 minute. Then print the data and psychrometric chart. Calculate the heat rate and amount of moisture removed from the air. During experiment, measure the time and the rate of condensation (100ml) from the beginning of the cooling process (stable temperature). Compare with analysis. 1

Thermalfluids Lab -MEC 554/ LS 1/SHAH Rev. 01-2009 5. DISCUSSION a) Answer all the problems in the experimental, and discuss the results obtained by explaining the factors that contributes to the air property changes for each process problems. b) Find the schematic of a modem air-conditioning system with advanced air treatment processes and explain the function of the main devices. c) Explain with suitable diagrams the operation and arrangements in an automotive airconditioning unit.

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Thermalfluids Lab -MEC 554/ LS 1/SHAH Rev. 01-2009 6. RESULT

Experiment No Process Reading

Sensible Heating

Steam Humidification

X

X

X

X

X

X

X

X

Cooling and Dehumidification

T1 ( TA d ) T2 ( TA w ) T3 ( TB d ) T4 ( TB w ) T5 ( TC d ) T6 ( TC w ) T7 ( TD d ) T8 ( TD w ) T9 ( T 1 ) T10 ( T 2 ) T11 ( T 3 ) T12 ( T 4 ) Qp Qr Qb Pevap ( P 1 ) Pcond ( P 3 )

X X X X X X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

ma mr Time

X

Drain Water (ml)

3

100 ml

Thermalfluids Lab -MEC 554/ LS 1/SHAH Rev. 01-2009

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