You are installing a basic air conditioning system inside of a house.
A direct expansion unit costs $3500. It has efficiency, seasonal energy efficiencyratio (SEER), of 15 Btu/wh.
Note: SEER = Cooling rate/Compressor power consumption.
Assume pressure of the working fluid (refrigerant R-134a) is constant at 1.5 MPa between the inlet and outlet of a evaporator.In Fresno, electricity from PG&E costs about $0.21/kWh.In the month of July, the outdoor temperature is 40 ? for 12 hours, 35 ? for 6hours, and 30 ? Celsius for 6 hours. You want the indoor temperature to remain 70? for 24 hours a day. Assuming the refrigerant temperature difference between theinlet and outlet of the evaporator is the same as the air temperature differencebetween indoor and outdoor.
Please answer the following questions.
1) If you want the month of July's electric cost to stay below $100 over the month of July by remaining the indoor temperature at 70oF for 24 hours perday, what is the required refrigerant R-134a's mass flow rate? What is the corresponding compressor power consumption?
2) Plot a range of R-134a's mass flow rates vs. corresponding range of coolingrates.
3) Plot a range of R-134a's mass flow rates vs. corresponding range ofcompressor power consumptions.
4) Plot a range of R-134a's mass flow rates vs. corresponding range of electriccosts of July.
Similarly, perform energy and cost analyses for an evaporative cooler unit (a nonvaporcompression cooling method) with a coefficient of performance (COP) of 20by repeating steps 1-4 listed above. Do research study on the equipment cost aswell as the background of one of the evaporative cooler types (direct, indirect, orindirect-direct). Compare the energy and cost analyses between the directexpansion and evaporative cooler units.
Your report must include but not limited to:
- Energy analysis
- Cost analysis
- Hand calculations
- Equations
- References/Citations