Analysis of Heat Loss in Air Conditioning Systems using RA3 Unit

This practical assignment focuses on analyzing heat loss in air conditioning systems using the RA3 Air Conditioning Unit. The experiment compares two methods: one with air recirculation and another with air expulsion. Data from sensors measuring temperature, pressure, and humidity are used to determine heat loss. The analysis reveals heat loss from the entry to the exit points, primarily due to conduction, convection, and radiation. The power requirements for the preheater are calculated for both tests, indicating that the recirculating system (Test B) is more energy-efficient due to lower power consumption. The conclusion emphasizes the importance of efficient air conditioning systems and suggests that recirculating systems are better suited for applications requiring consistent air heating due to their energy-saving capabilities. Desklib provides this document as a valuable resource for students, offering access to similar solved assignments and past papers.

Test A
It is clear there is heat loss as air flows from the entry point to the exit point from the data recorded at
entry duct after the preheater, T2=30.4 degrees and at the exit of the re-heater, T4=29.2 degrees. The
heat loss calculated, T4-T2=-0.331 degrees. The air temperature loss doubles as air exit the artificial
room at the point where T5 is captured, calculate as T5-T4=-0.0630degrees.
The air losses heat due to several factors. When temperature T2 is high, more heat loss will be
expected as air passes through the room to the exit due to the high-temperature gradient between the
heated air and the surrounding air.
Heat is lost through three processes: conduction, convection, and radiation.
Having the inlet and outlet of the system open to the atmosphere, as air passes through the compact
duct into the room heat is lost through one or a combination of the heat transfer processes mentioned.
Preheater power requirements in test A and B assuming no heat loss between T1 and T2
Applying the heat loss equation provided above with the assumption indicated, we can calculate the
power supplied to preheater in Test A is 0.209Kw (209 watts) vice seer vee in the test B which is
0.239 kW (239 watts). The power requirements in Test B are higher than in Test A due to the higher
entry temperature into the preheater in Test B. The higher temperature is attributed to the recirculation
of already heated air in the system.
Test B
During the airflow from the entry point T1 all through the system and recirculation, heat loss is
calculated and we get a positive value (0.0472) implying heat gain during the process. The heat
gained is due to the continuous reheating of the existing air being recirculated repeatedly and each
cycle.
However, heat loss can be calculated between T4 and T5 from the entry of the room until the exit to
get -0.878 degrees. This is expected as the room to be air-conditioned. The room experiences heat loss
due to increased space or volume and ideally due to poor insulation from the surrounding
environment.
4. Conclusion
The tests were successful in demonstrating one critical aspect in air condition systems that are used in
buildings. Despite making assumptions and human errors that may have been recorded and carried
forward in the calculations, it was clear that one system is better than the other is and suited for
different air conditioning applications.
Air conditioning is a paramount aspect in buildings to be able to provide clean air at the required
temperature at any season of the year. When it comes to spaces that required air heating, it is a good
practice both financially and environmentally to save on energy requirements for the systems. In such
scenarios, using the recirculating Duct-room systems as conferred from the experiment. Test B is
more energy efficient as they require less power to maintain the high temperatures within the air
conditioning system than test A.