Assignment Instructions:

You are given two air conditioning systems with different subcooling and superheat values. One system tagged $($#$1)$and $($#$2).$ You are tasked with plotting the conditions of both systems on an R$-410$A Mollier Chart and calculating key metrics.

System Parameters:

System $1$

$5$F subcooling

$30$F superheat

$$ Low side pressure: $105$ PSIG

$$ High side pressure: $340\mathrm{.}8$ PSIG

System $2$

$20$F subcooling

$15$F total superheat entering the compressor

$$ Low side pressure: $115$ PSIG

$$ High side pressure: $418$ PSIG

Tasks:

Using the provided system conditions, complete the following tasks for both systems:

$1.$ Plot the Systems on a Mollier Chart:

o Plot the low and high side conditions $($based on pressure$)$ for both systems on an R$-410$A Mollier chart.

o Ensure that both subcooling and superheat values are plotted accurately.

o Use colors to differentiate between the two systems and different components.

$2.$ Calculate the Following Metrics for Each System:

$0.$ Total Heat of Rejection $($THOR$)$: The amount of heat rejected by the system$$s condenser.

$1.$ Net Refrigeration Effect $($NRE$)$:

$$ First, calculate the NRE without superheat.

$$ Then calculate NRE including superheat.

$2.$ Heat of Compression $($HOC$)$: The heat added during the compression process.

$3.$ Refrigerant Temperature Leaving the Compressor:

$4.$ Flash Gas Percentage: Calculate the percentage of refrigerant that vaporizes immediately after expansion.

$5.$ Compression Ratio: Use the high side and low side pressures to calculate the compression ratio.

$6.$ Coefficient of Performance $($COP$)$: Calculate the efficiency $($COP$)$ for both systems.

$3.$ Write a Summary:

o Provide a $1-$page written comparison$$of the two systems, explaining how differences in subcooling and superheat affect performance.

o Diagnose the potential issue with the System$$that has an issue.

o Discuss what the cause of the performance differences might be and suggest potential solutions for the defective system.

$$

Submission Requirements:

$$ Mollier Charts:

o Must be submitted with your full name.

o Neatly plotted with color$$for each system.

o Labels for all critical points $($low side, high side, subcooling, superheat$).$

$$ Calculation Work:

o Show all steps in your calculations with proper units $($BTU$,$ PSIG, $$F$,$ etc.$).$

o Submit your calculations clearly written or typed.

$$ Summary Report:

o Must be neat and organized, addressing all required points.

$$

Additional Guidelines:

$$ Precision: Ensure you use accurate R$-410$A properties from the Mollier chart or refrigerant tables.

$$ Units and Significant Figures: Maintain consistent units throughout $($e$.$g$.,$ PSIG, $$F$,$ BTU$)$ and round answers appropriately.

$$ Interpolation: If the values you need are between the points available on the Mollier chart, perform proper interpolation.

$$ Flash Gas Percentage: Use the chart or tables to estimate the flash gas formed after the expansion process.

This assignment is designed to deepen your understanding of refrigerant system performance and provide hands$-$on practice with reading Mollier charts and performing system diagnostics. If you have any questions, feel free to reach out before the due date.

Good luck!