1) My opinion of Austin City Limits is:

A. Expensive

B. Hot

C. Crowded

D. Didn’t go

E. Great

Admin

• Messed-up morning office hours this week• ARE 465

• HW #2 due on Thursday (by 5 pm w/ no late penalty)• HW#3 (more straightforward) handed out on

Thursday, due on 9/30/04• NO LATE SUBMITTALS

• Midterm #1 10/05/04• Practice midterm handed out on 9/28/04

Objectives

• Describe lamp technology• High intensity discharge• Innovative technologies

• Calculate required lighting levels• IESNA Handbook• Handout (from Tao and Janis)

High Intensity Discharge (HID)

• Arc through conducting vapor

• High temperature and pressure• Ceramic or quartz tubes• Glass protective casing• Figure 3.18

Ref: Tao and Janis (2001)

Types of HID LightingType Color Temp.

(K)Efficacy

(lumens/W)CRI Lifetime

(1000 hours)

Mercury 5710 20-60 15-50 24

HPS 2100 140 22-70 16-40

SOX 1740 180 ~0 10-201

Metal Halide

3600 ~100 <70 10-20

1minimal decline in output with aging

Issues with HID lighting

• Long start-up ~ minutes• Arc needs to stabilize, heat vapor

• Even longer restart

• Up to 40,000 hour life time

Ref: Tao and Janis (2001)

Ref: Tao and Janis (2001)

2) Which of the following statements is not true?

A. HID lamps have shorter lifetimes than CFL lamps

B. HID lamps require ballasts

C. Fluorescent lamps require ballasts

D. Fluorescent lamps have a higher CRI than HID lamps

3) What is a difference between a mercury vapor lamp and a fluorescent lamp?

A. A fluorescent lamp doesn’t require an electrical arc.

B. A fluorescent lamp doesn’t have mercury vapor in.

C. A fluorescent lamp uses a phosphorus screen to create light.

D. A fluorescent lamp needs a ballast.

What is next in lamp technology

• LEDs• Exit signs• Need brighter white

• Microwave lighting• Hugely efficient• Possible interference with wireless networks

Ref: Tao and Janis (2001)

Exit Signs

Comparison

Type Power (W) Lifetime

Incandescent 40 2 – 8 months

Fluorescent 10 – 25 1 – 2 years

LED ~1 10+ years

LEC ~0.25 30 years (?)

Tritium 0 10 – 20 years

Comparison

• Incandescent: 40 W × 8760 hr/year = 350 kWh• Demand charges, maintenance, additional cooling• Uneven illumination

• LED: 1 W × 8760 hr/year = 8.8 kWh• 1/40th of the energy charges, lower demand, less

maintenance, lower cooling bills• More even illumination

4) Which of the following lighting types would not be appropriate for its

corresponding use?

A. LED – traffic lights

B. SOX – highway lights

C. HPS – football stadium in Austin, TX

D. CFL – loading dock in Minot, North Dakota

Lamps are not the only thing

• Fixtures (luminaires)• Lamp type and number• Power requirements• Ballast• Application requirements• Mounting• Fixture control• Special feaures• Distribution

Lighting design calculations

• What is the space being used for?• How much light do the occupants need?

• What factors will influence light levels?• Preliminary calculations

• What fixtures/lamps/ballasts should you use?• Where should you put them?

What about quality of light?

• Glare

• Comfort• Similar to thermal comfort

• Evenness• Around work area• On surfaces

• Color issues• CRI, color temperature

Handouts

• Step-by-step procedure• Some guidance in your textbook

• Best source is IESNA Handbook• Focuses much more on quality issues• Need to reference it for specific spaces

5) Which of the following factors does not influence the amount of illumination

needed (designed for) in a space?

A) Type of activity performed

B) Shape of the space

C) Age of occupants

D) Speed or accuracy required by the task being performed

Illumination Requirements

• Type of activity

• Age

• Speed/accuracy issues

• Contrast

IES Handbook

1. Pick the task and the work surface

2. Select the category• Determines illumination range (3)

• Ambient lighting

• Lighting on the work surface

• Task lighting on the work surface

3. Evaluate weighting factors

4. Pick illumination value

Examples

• Drafting in 5th floor lab

• Computer laboratory• In the same room?

• Sushi counter in a restaurant

• Dining area in same restaurant

6) You are designing the lighting for a sewing room in a nursing home. The total weighting factor and the total amount of illumination needed are ____ and ____.

A) +2 and 1000 lux

B) +2 and 500 lux

C) +1 and 1000 lux

D) +1 and 2000 lux

Summary

• Describe lamp technologies• Select for lighting design

• Determine how much light is needed in a space