180 likes | 389 Views
Energy Saving Devices. Are they Cost-Effective? Brad Pittler & Patrick Sims. The Customer. Southern Methodist University University with roughly 10,000 students Michael Vangelli Campus Planning and Plant Operations Electrical Engineer.
E N D
Energy Saving Devices Are they Cost-Effective? Brad Pittler & Patrick Sims
The Customer • Southern Methodist University • University with roughly 10,000 students • Michael Vangelli • Campus Planning and Plant Operations • Electrical Engineer
Collect data regarding study room, rest room, and copy room usage. Gather information regarding energy efficient devices Compare installation costs of energy saving devices to what they would save over a period of time Issues to be Resolved
Automatic Using “Intellitimer” Device Using Circulation records from libraries Using sign-out sheets Manual Counting people entering and exiting rooms Using anecdotal evidence when available Method of Data Collection
Data Analysis Objective • To gather sufficient data to: • Develop a mean for each type of room • Develop a picture for room usage over a period of time • Develop a representative basis for recommendation
Problem Development • Data collected formed a cost/benefit problem (with the following assumptions): • The data collected was representative of the norm • The costs would be static, and labor would be ignored • Inconvenience of installation had no cost
Goals were to calculate energy-cost savings for two different types of energy saving devices. Calculating the time until the device pays for itself in energy savings Model Development • Implemented into the model three factors: • Data Gathered on Occupancy • Cost of Energy per kWh • Average Energy used per room (in kWh.)
The Model • Annual Savings Model (Percent of time unoccupied) X (Cost of energy) X (Energy used per room) X (16 hours) X (350 days) This will calculate total energy savings.
The Model (Cont.) • The Payback Period T = Unit Cost / Annual Savings This will calculate how long the unit will take to “pay for itself” via energy savings.
Choosing the Devices • Gather information on options used for energy savings • Contact other organizations to learn about their choices • Learn about drawbacks and costs to install the devices
The Contenders • Leviton develops devices that use both IR and Ultrasonic to detect occupancy • WattStopper offers devices using either IR or Ultrasonic to detect occupancy
In two of the three cases, installation of either device would have a payback period of less than two years. Both devices had positive and negative points. The decision would be made on choice between cost and convenience. Further study of room usage patterns could contribute to better choices. Conclusions