2W04 Assignment 6 -2009 Solutions

2W04 Assignment 6 -2009 Solutions - Solutions Assignment#6...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Air Cond. A Air Cond. B Solutions Assignment #6 1. An electric resistance heater which consumes 5 kWh of electricity and supplies 6 kWh of heat to a room. Transferring 5 kWh of heat to an electric resistance wire and producing 6 kWh of electricity. 2. A decision is to be made between a cheaper but inefficient air conditioner and an expensive but efficient air conditioner for a building. The better buy is to be determined. Assumptions The two air conditioners are comparable in all aspects other than the initial cost and the efficiency. Analysis The unit that will cost less during its lifetime is a better buy. The total cost of a system during its lifetime (the initial, operation, maintenance, etc.) can be determined by performing a life cycle cost analysis. A simpler alternative is to determine the simple payback period. The energy and cost savings of the more efficient air conditioner in this case is kWh/year 13,500 = ) 0 . 5 / 1 1/3.2 kWh/year)( 000 , 120 ( ) COP / 1 COP / 1 )( load cooling Annual ( B) of usage energy Annual ( A) of usage energy Annual ( savings Energy B A = = = $1350/year = $0.10/kWh) kWh/year)( 500 , 13 ( energy) of cost Unit )( savings Energy ( savings Cost = =
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 2

2W04 Assignment 6 -2009 Solutions - Solutions Assignment#6...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online