Building Operator

Certification – Level I

A Partnership of the CUNY Institute for Urban Systems

Building Performance Lab, the CUNY School of Professional

Studies, and the New York State Energy Research & Development

Authority

Lesson 2 Review

Section 1 Lighting Fundamentals (60 mins)

Section 2 Lighting Quality (20 mins)

Section 3 Lighting Controls (60 mins)

Section 4 Lighting Maintenance (40 mins)

Lesson 3: Lighting Technology

Lesson 3 Objectives • Understand relative efficiencies of various lighting

technologies

• Understand Light Levels and calculation of Lighting Power Density

• Be able to make a schedule of light fixtures to find total kW used

• Be familiar with Occupancy Controls, Bi-level Lighting, Day-Lighting and planning for Lighting Maintenance

• Be familiar with new code/legislative requirements

impacting commercial lighting systems.

Introduction Lighting is an interesting and important topic because: We are all familiar with it and use it daily both at home and at

work – yet because of this it is sometimes overlooked…

Lighting usually offers the greatest, and easiest, energy savings opportunity in most commercial buildings.

Lighting systems offer numerous “win/win” opportunities for improvements in energy efficiency AND workplace productivity.

Poorly designed – OR – maintained lighting systems can cost far more in lost productivity than in the energy wasted.

And finally – NEW NYC LOCAL LAW 88: Mandatory Lighting Retrofits for all buildings >50,000 ft2 – read more at http://www.nyc.gov/html/gbee/html/plan/ll88.shtml.

Commercial Buildings – Energy Use vs. Energy Cost

Light Costs 45%

Other Energy Costs 55%

Energy COST 30-60%

Lights 30%

Other Uses 70%

Energy USE 20-40%

The Expense of Lighting

Since electricity is a relatively expensive energy source, lighting systems cost more to operate than other building energy systems, such as heating which uses natural gas or other fossil fuels.

Goals of Sustainable Lighting

Healthy Workplace

• Good indoor environment

• Workplace satisfaction

• Increased performance/productivity of occupants

Low Resource Use • Energy efficiency

• Reduce GHG (Green House Gas) emissions

• Lower operating cost

We want to accomplish BOTH of these objectives.

Efficient Lighting Practices • Use only the energy required to accomplish the task and

no more.

• Use the most efficient equipment to efficiently produce and deliver the light.

• Design the environment to achieve the desired lighting quality for the intended task.

• Control the light to reduce run-time: If you don’t need it at full power, turn it down. If you don’t need it at all, turn it off.

• Maintain the light to ensure efficient operation and long life.

Section 1: Lighting Fundamentals

I. Lighting Terms & Basic Calculations

II. Lamps Types

III. Fixture & Components

IV. Lighting Cost Analysis

• The technical name for a light bulb is a Lamp.

• The lamp is installed in a fixture, also known as a luminaire.

• Lumens = light output at the source (i.e. the output of a lamp).

• Light Level = the amount of light reaching a surface. Measured in “Footcandles”

using a Light Meter. Regulated by Energy Codes.

Lighting Terms

Lumens

Light Level

Lamp

Fixture/Luminaire

Watts: Energy input (to a lamp).

Efficacy/LPW: Measure of light output efficiency. Term used is “LPW” (Lumens per Watt)

Efficacy of different types of lamps varies widely.

Lighting Power Density/LPD: Power consumption per square foot.

Term used is “LPD”

Measured in Watts per Square Foot (W/Ft2)

Also regulated by Energy Codes

Terms – Measuring Light

LPW: Comparing Energy Efficiency LIGHTING EFFICACY

LPW

FUEL EFFICACY

MPG

150 miles ------------

10 gallons 15 mpg =

1000 lumens ------------ 20 watts

50 lpw =

Lighting Power Density (LPD): Calculating Energy Usage of Lighting

Lighting Power Density = Watts per sq foot

Energy Codes are written this way Codes limit the allowable amount of energy to be drawn by the

lighting in a space.

Reflects “design lighting load” in Watts Lighting Load is rated in Kilowatts. This is the amount of power

the lights are drawing “right now” on a “constant draw” basis.

Does not take lighting level into account.

Lighting Standards & Energy Codes

The Illumination Engineering Society (IES) has developed recommended ranges of illuminance (FC) levels for a wide range of visual tasks.

ASHRAE 90.1: Energy codes are written to place a maximum limit on the allowable LPD in different space types.

Exercise: LPD Calculation

15

LAMPS BALLAST Room

# Fixture Type # of

Fixtures # of Lamps per Fixture

Wattage per Lamp

Input Voltage

Input Current

Power Draw

# per Fixture

101 Fluorescent 12 3 40 120 .84 100w 1

84’

28’

LPD = Energy (Watts) Area of Room (sf)

Lamp Types

Common lamps are organized into major families, depending on the way the light is produced.

Fluorescent Linear Compact (CFL)

Light Emitting Diode (LED) Also other emerging technologies such as Photoluminesence

Incandescent Standard - filament type based on pure resistance Tungsten-Halogen

High Intensity Discharge (HID) Mercury Vapor Metal Halide High Pressure Sodium Low Pressure Sodium

• Very low EFFICACY.

• Being phased out.

• Can be directly replaced by CFL’s.

CFL replacements are often part of “free” energy improvements offered through utility-sponsored energy efficiency programs.

Incandescent

Fluorescent

• Newer versions (T8, T5) are highly efficient.

• Require ballasts to control electric current.

• Ballasts & lamps are NOT directly interchangeable from one type to another.

http://ww

w.m

asonpud3.org/conservation/comm

erciallighting.aspx

Reading Fluorescent Lamp Specifications When comparing, lamp ordering codes and labels vary by manufacturer but similar abbreviations and codes systems are used.

For more information: www.gelighting.com/na/business_lighting/education_resources/literature_library/catalogs

Special aspects of newest FL’s

20

6-Light T5HO Fluorescent High Bay Fixture

• Also “gas-discharge” – produces visible light by passing an electric current through a mixture of gases.

• As the lamp warms up, the gas pressure increases and the light gets brighter.

• Typically used for outdoor or high-bay applications.

• Types: • High-pressure sodium • Low-pressure sodium • Metal Halide • Mercury Vapor (no longer recommended, being

replaced by sodium or metal halides).

High Intensity Discharge (HID)

HO Fluorescent vs. Metal halide

22 Chart courtesy of www.prolighting.com

• Traditionally used for exit signs and street lamps.

• Newer uses can replace fluorescents and incandescents.

• Waste heat rejection is important consideration – inadequate heat rejection shortens LED life.

LED (Light Emitting Diode)

The illustrations above are LED linear fluorescent replacements that are also

manufactured in colors.

Efficacy of Different Lamps

Source: http://www.ecmag.com/section/lighting/lighting-design-101

Ballasts A ballast is an electrical device that performs two functions:

• Starts lamps by providing initial high voltage to strike an arc between electrodes.

• Regulates light output by maintaining normal operating current and voltage.

Fluorescents and HID both use ballasts.

Ballasts are NOT generally interchangeable between lamps. Incorrect ballasts can reduce lamp life and/or light output, if they start the lamp at all.

Old Ballasts – Electro-mechanical – Low Frequency 60 Hz

New Ballasts – Electronic Solid State – High Frequency 5000 Hz

Symptoms – Lamp/ballast end of life

26

Luminaires (Fixtures)

Components:

• Housing

• Electrical connection

• Lamp holders (sockets)

• Lamps & ballasts

• Lenses & louvers

• Reflector

• Trim

A luminaire is a complete lighting unit, consisting of a lamp or lamps, together with all the components required to distribute the light, position the lamps, and connect the lamps to a power supply.

Luminaire Types – by Classification

Classification by light distribution (Which way is the light going?)

Classification by mounting condition (How is the fixture positioned?)

Lighting Costs - Lifecycle

What is approximate life span of each type? • Incandescent: 1,500-2,000 hours • Fluorescent: 20,000-25,000 hours • LED: 40,000-50,000 hours Must look at overall lifecycle cost, based on life span – incandescents are cheapest but LED uses less energy and lasts longer.

How they rate in Efficacy, Cost & Life Span • Incandescent: Low • Fluorescent: Medium • LED: High Low cost = low efficiency, low life span (you get what you pay for).

http://www.maxlite.com/_assets/images/faqs/ML.TypesOfLighting.FaqGraph.jpg

Two approaches: • Top down - At the beginning, to estimate energy used

by the different systems • Bottom up - After, to determine actual lighting energy

use.

Estimating Lighting Energy Use & Cost

Top Down Lighting Analysis

Bottom Up Lighting Survey

Section 2: Lighting Quality

Choosing the right light isn’t just about wattage… Lighting has to aid the task rather than detract. What do we mean by Lighting Quality?

• Light Levels - The brightness of the light.

• Light Color – The color that the light appears.

• Absence of glare – A bright source of light compared to the surroundings.

• Even distribution of light in a space.

Light Levels Guidance provided by IESNA (previous slide 14) – but to help decide what light levels are appropriate for a given space or activity, consider factors such as:

• Type of Activity: ie. corridors/hallways vs. office or classroom. Corridors are comfortably lit at 10 fc - only need ambient lighting or relatively low-level background lighting. Classroom/office would require higher.

• Workplane: The surface where the light is being used (for example, at a desk).

• Age of occupants - i.e. quality of eyesight.

Color Temperature The color temperature represents the appearance of a lamp source, as measured in degrees Kelvin (K).

• Low color temp. appears “warm” - toward yellow end of the spectrum. Higher color temp. appears “cooler” - toward blue end of the spectrum.

Color Temperature for Fluorescent Lamps

Daylight 5000K also called Full Spectrum Cool White 4100K Neutral White 3500K Warm White 3000K and below

Rules of Thumb

• Blue/cool light for business/professional setting.

• Warmer light for home/residential setting.

For more info: http://www.greenoptions.com/wiki/picking-color-temperature-for-your-light-bulbs

Glare Glare – A bright source of light compared to the surroundings. • Can be an issue of reflectance – light

reflecting from a surface impacting your comfort or ability to see. Example: sun reflecting off of your

computer screen).

• Can also be an issue of contrast – where light from one source or object makes it hard to see an adjacent object. Example: car headlights make it hard to

see the road.

Why is glare a problem? Distracting, discomfort – affects focus on main activity/task.

Light Distribution Glare has to do with the way light is distributed in the room. Direct light emits straight from its source to the intended surface. Diffused (or indirect) light is reflected and scattered in all directions, thus reducing glare.

Section 3: Lighting Controls More effectively controlling the light goes beyond energy savings:

Cost savings > Eliminate unneeded light > Extend lamp life

Security > Automatic vs. Manual switching > Motion Detection / Occupancy Sensing

Lighting Quality > Match appropriate light level to task > Provide for increased Visual Comfort

Controlling On-Hours We can significantly minimize the number of on-hours using controls.

• Circuiting • Switching • Dimming

• Scheduling: Using operating schedules and time controls to turn lights on when needed and off when not needed. (On and off by schedule).

• Task Lighting: Adjusting lights to levels appropriate to the existing occupancy, tasks, or conditions. (On and off by occupancy).

• Daylighting: Sometimes called Daylight Harvesting. Turning off or dimming electric lighting when sufficient daylight is available from windows and skylights. (On and off by light).

Circuiting Circuiting - When designing floor plans for lighting all of the lights that serve the same basic function in the same general area will be put on the same circuit. Because of the limits of the load that can be placed on a lighting circuit breaker, typically 15 amps, a large area may need several circuits. Lighting and convenience or equipment circuits are generally kept separate.

> These limits present opportunities. If the owner wishes for all of

the lights to be controlled by a single switch, a relay can be used to tie all of the circuits together. These separate circuits can be used for different control strategies to meet differing use and conservation needs.

> Completely on and off.

Bi-Level Switching Two levels of light brightness are possible > High Level is used during occupancy > Low level is used when not occupied (vs dimming which is gradual on

to off) Lamps in the fixture are on different circuits and switches

Dimming desirable for many applications Manual dimming

o Incandescent easy to dim o Dimming by resistance device does not save energy

o The resistors heat up and the light energy becomes heat energy.

o Fluorescent - needs dimmable ballast Automatic dimming

o By schedule o When unoccupied o When daylight available

Dimming

• Time clocks • Programmable lighting control panels that can integrate to

BAS. • Prioritization for peak load shaving.

Scheduling

Occupancy (and VACANCY!) Sensors

0

10

20

30

40

50

Private OfficeOpen OfficeConference RoomComputer RoomRestroom

Typical Energy Savings (%)

Occupancy sensors switch lights on/off based on when people are present. Notice the savings go up if the room is used intermittently. Storerooms, warehouses, school rooms and corridors would also benefit from occupancy control. The new Energy Code of NY City requires the use of the Sensors. Two Types: Passive Infrared (PIR) and Ultrasonic

Occupancy sensor types

45

Best applications • Small enclosed spaces without obstructions. • Areas with high air movement (e.g. computer

rooms). • Areas with high ceilings (e.g. warehouses). • Hallways and storage aisles. • Spaces with areas of unwanted detection. • As wall switch replacements.

Poor applications • Partitioned restrooms. • Storage areas with obstructions. • Large enclosed spaces with low ceilings.

Best applications • Large offices and classrooms. • Enclosed areas up to 2,000 square feet. • Storage areas with obstructions. • Enclosed hallways. • Partitioned restrooms.

Poor applications • Non-enclosed areas. • Areas with high air movement. • High ceiling areas (over 15 feet). • Spaces with areas of unwanted detection .

Daylighting

Source: Advanced Lighting Guidelines 1993

Daylight can be used as a lighting resource by enhancing the admission of sunlight to REPLACE or SUPPLEMENT interior light.

Architectural design element.

Graph: shows varying power needed throughout the day.

What do we need to keep in mind when using daylight?

For Further Info: http://www.advancedbuildings.net/files/advancebuildings/DaylightingGuideOfficeInteriors.pdf

Daylighting: How Light Enters a Room

Goal: Get sunlight deeper into interior spaces, and: • Uniform Distribution • Without the glare of direct sun Components: • Top Lighting – Skylight • Side Lighting • Light Shelf – High on Window • Light Shelf – Low on Window • High Reflectance Ceilings

Daylighting: Controls Control systems • Dimmer Control to maintain a

constant level of light in the room.

• Measures the light level, and responds.

• Without adequate control of artificial lighting, daylight savings will NOT be realized.

Operational Issues • “Hunting” – sensor reacts too

quickly and variation in light output becomes noticeable – a nuisance.

• Perimeter vs room interior controls – varying amount of dimming at perimeter vs. interior.

Section 4: Lighting Maintenance The final strategy and an important one.

A lighting system must be properly maintained to continue to provide high quality, efficient lighting.

• Lighting maintenance can maximize operating benefits (productivity, security, sales, etc.).

• Systematic maintenance helps extend product life. Light output decreases over time (depreciation) but is recoverable with maintenance.

• Fixtures with lower output lamps may require more frequent cleaning to maintain minimum light levels.

Depreciation

Lighting Maintenance Plan A comprehensive lighting maintenance plan addresses multiple facets:

• Replace old ballasts

• Clean lenses and/or replace badly discolored lenses & diffusers

• Group re-lamping

• Clean luminaires at the time of relamping (more often in dirty locations).

• Maintain reflective room surfaces, especially those rooms with indirect lighting.

• Check lighting controls – must be maintained for proper performance and compatibility with current operations.

Let’s look at several of these in more detail.

Replacing Old Ballasts

Why replace old ballasts? • New ballasts – more efficient & last longer (less need for replacements). • PCB’s in older ballasts are hazardous – even if T12 lamps in your facility

were replaced with T8’s, you could still have old ballasts.

Group Relamping Replace large groups of lamps all at once.

Provide some interim replacement (with salvaged lamps).

Use number of burned out lamps as an indicator of lamp life.

Typical Fluorescent Lamp Mortality Curve

020406080

100120

20 40 60 80 100 120Percent Average Life

Perc

ent S

urviv

ing

At 60% average rated life, the lamp mortality curve begins to fall significantly. At 80%, it falls very steeply. It is recommended to replace ALL lamps at 80% of rated life. Group relamping is most effective when good records are kept to trigger the next relamping. (The best lamps that are replaced at group relamping time may be saved for spot replacements or service elsewhere.)

Reading Assignment for Week 4 -FEMP Sec. 9.10 (“Motors” – pages 9.109 – 9.119) -Herzog Appendix A: pp. 149-164