Heating Ventilating Air Conditioning (HVAC)
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Common Report
Individual Report
Discussion
No
process
In this section, the temperature in this system does
not changed where temperature is 25.2°C. This is because no process occurs in
this section. There is no factor contributes to change the air property changes
in this process. We, conclude that all the value readings recorded at
temperature in and out are all in the room temperature
Heating
process
After the experiment is conducted, we clearly can take
the reading temperature at fan inlet with 25.2°C (dry) and 21.3°C (wet) on test
Ref. 1. After steady condition is achieved, the temperature was raised to 36°C
(dry) and 29.5°C (wet). Based on this experiment, the temperature increase is
not consistent because of the factor that contributes to heating process. The
air temperature reached to maximum value of 36°C (dry) and 29.5°C (wet) but the
relative humidity value slightly down compare to relative humidity at fan
inlet. This shows that the moisture is decreasing upon the heating process. The
air relative humidity values drop from 70% to 64% (dry).
Cooling
process
Based on the experiment, at this section, the
compressor of refrigerator system is switched on and the process called cooling
process. By referring to the result, we can determined that the temperature of
air decreasing from 36°C (dry) and 29.5°C (wet) to 27°C (dry) and 26.5°C (wet)
respectively. The data proved that the cooling process decrease temperature
value. The air relative humidity is increasing from 64% to 98%. This shows that
the moisture is increasing upon cooling process.
Humidification
process
For this section, the water vapor or moisture are
added to the air without changing the temperature. The temperature still has
changed after humidification process that decreased and increased from started
to second section. Based on the theoretical, humidification process does not
affect the temperature but in experiment, the temperature still changed. The
value of air humidity in this section also has changed but in controlled value.
Thus, the percentage error between
theoretical and the experiment data also in controlled value.
Dehumidification
Dehumidification is a psychometric process where the
water is removes from the air as the air temperature falls below the dew point
temperature. The air relative humidity decreased from 98% to 68%. This shows us
that moisture percentage in the air drop in dehumidification process. In
addition, the temperature of the air is increased from 27°C to 36°C. This prove
that temperature different involves in dehumidification process.
Based on the result that we have calculated, the
specific work done for test ref. 1 are 35kJ,14kJ and 2kJ for section B, section
c, section D respectively. Next, for actual work done are 336.78kJ, 836.72kJ
and 769.33kJ for section B, section C and D respectively. Power input for test
ref. 1 is 187.2W and the efficiency is 97.73%.
Next, for the test ref. 2 the specific work done are
337.75kJ, 835.77kJ and 769.34kJ for section B, section C and section D.
Besides, the actual work done is the same as test ref. 1 because we have used
average value for test ref. 1 and test ref. 2. Lastly, the power input is
204.1W and the efficiency of the process is 97.63%.
Conclusion
As the conclusion, we can understand the air
conditioning system. After the experiment was conducted, the most importance
role is heat and moisture in the air-conditioning system. Air conditioning is
the cooling of indoor air for thermal comfort. In a broader sense, the term can
refer to any form of cooling, heating, ventilation, or disinfection that
modifies the condition of air. An air conditioner is an appliance, system, or
machine designed to stabilize the air temperature and humidity within an area
(used for cooling as well as heating depending on the air properties at a given
time), typically using a refrigeration cycle but sometimes using evaporation,
commonly for comfort cooling in buildings and motor vehicles. (Ustudy.in)
There are some advantages of air-conditioning system; (infomechy)
- Improved
working efficiency, reduce stress and absenteeism
- Increased
sales, productivity, comfortless
- Less
cleaning materials and furniture last longer
- Suitable
environment for plants growth, process, electronic and laboratory areas
- Reduce
internal and external pollution
- Less
risk of fire or damage due to static electricity caused by dry air
From the result of the experiment, the value of mass
flow rate of air and vapor mixture is higher than the value of mass flow rate
of the dry air. It shows that the flow rate of air and vapor mixture is much
more used in the air conditioning unit. During the heating process, the highest
temperature can be obtained is 32.53°C. It is because human cannot resist in a
high temperature that more than around 33°C since the normal temperature of
human body is 37°C. The temperature of cooling process, humidification process
and dehumidification process that obtained during the experiment is in the
range from 19°C to 27.6°C. If compared with the theoretical analysis, there was
a difference that maybe occurred by an error during the experiment. Maybe the
air conditioning unit was not being checked regularly by the schedule
maintenance and the reading should be taking at least three times for a better
or accurate result
References
1. (n.d.). Retrieved from Ustudy.in:
http://www.ustudy.in/node/1206
2.
(n.d.). Retrieved from infomechy:
http://infomechy.blogspot.my/2012/11/lab-report-sand-testing-preparation-gfn_4.html
3.
Thermal Engineering. (2013). Singapore: Mc
Graw Hill Education.
4.
R.S.Khurmi, J.K.Gupta. (2007). Refrigeration and Air Conditioning. Ram
Nagar, New Delhi: Eurasia Publishing House.
5. Yunus A.Cengel, Michael A.Boles.
(2011). Thermodynamics An Engineering
Approach. 1221 Avenue of Americas, New York,
NY10020 : McGraw-Hill.
