1 / 16

Energy Conservation

Energy Conservation. Physics 1303 3/24/03. Reducing energy consumption may help alleviate environmental problems:. Conserve fossil fuel resources Reduce CO2 emissions Reduce extraction impacts Reduce use of water and other resources. There are two ways to reduce energy consumption.

desma
Download Presentation

Energy Conservation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Energy Conservation Physics 1303 3/24/03

  2. Reducing energy consumption may help alleviate environmental problems: • Conserve fossil fuel resources • Reduce CO2 emissions • Reduce extraction impacts • Reduce use of water and other resources.

  3. There are two ways to reduce energy consumption. • Alter lifestyle – e.g. public transportation v.s. private cars. • Increase the efficiency of energy use.

  4. Efficiency – General Definition Efficiency = useful output / energy input

  5. Example 1 – Fluorescent Bulbs • A 20 watt Fluorescent bulb produces the same luminous flux as a 100 watt incandescent bulb. • So, the Fluorescent bulb is 5 times more efficient. • Work the Lighting Efficiency problem.

  6. Example 2 – Space Heating

  7. Space Heating • The amount of heat that flows through a wall or window may be calculated by the following formula: Heat Loss (in Btu/hour) = Wall Area •(Tin - Tout) ¸ R-value

  8. How do we lower energy consumption? • Lower Tin. (Lifestyle change) • Decrease wall size (Lifestyle change) • Add insulation to the walls. • Increase efficiency of heater.

  9. Example 3 – Air-Conditioner Efficiency The efficiency of Central A/C units is governed by U.S. law and regulated by the U.S. Department of Energy. Every A/C unit is assigned an efficiency rating known as its seasonal energy efficiency ratio (SEER). The SEER is defined as the total cooling output (in Btu-British thermal units) provided by the unit during its normal annual usage period divided by its total energy input (in Watt-hours) during the same period.

  10. Air-Conditioner Efficiency - SEER The SEER is displayed on a yellow label affixed to the A/C unit. Higher SEERs are better. The minimum SEER allowed by law for a central A/C is 10 for a split system or 9.7 for a single-package unit. The best available SEER is about 18, while many older units have SEER ratings of 6 or less. Most consumers should look for a SEER of 12 or higher when buying a new A/C system.

  11. Air Conditioner Efficiency Calculation

  12. Retrofit and Payback Suppose an older home in San Antonio is equipped with a central air-conditioning unit with SEER rating equal to 6 and that this home consumes 36,000 kWh of electrical power each year to power this system. Suppose this system is replaced by a central unit with a SEER rating equal to 18.

  13. 1.  How much energy (in kWh) is consumed annually by the central A/C unit after the upgrade? Energy Consumed = = 36,000 kWh • Old SEER / New SEER = 36,000 kWh • 6 /18 = 36,000 kWh • 1 /3 = 12,000 kWh

  14. 2.  How much energy is saved annually by switching to the A/C unit with the higher SEER rating? Energy Saved = = 36,000 kWh – 12,000 kWh = 24,000 kWh

  15. 3.  How much money is saved annually, assuming that the cost of electricity equals $0.10/kWh? Money Saved = = 24,000 kWh • $0.10/kWh = $2,400

  16. 4.  What is the payback period if the cost of purchasing and installing the new A/C unit equals $4,800? Cost = $4,800 Savings= $2,400/year Payback = Cost / Savings = 2 years

More Related