Building Operator Certification Level I

Transcription

1 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

2 Lesson 2 Review

3 Lesson 3: Lighting Technology Section 1 Lighting Fundamentals (60 mins) Section 2 Lighting Quality (20 mins) Section 3 Lighting Controls (60 mins) Section 4 Lighting Maintenance (40 mins)

4 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.

5 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 ft 2 read more at

6 The Expense of Lighting Commercial Buildings Energy Use vs. Energy Cost Energy USE 20-40% Energy COST 30-60% Lights 30% Other Energy Costs 55% Other Uses 70% Light Costs 45% 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.

7 Goals of Sustainable Lighting Low Resource Use Energy efficiency Reduce GHG (Green House Gas) emissions Lower operating cost Healthy Workplace Good indoor environment Workplace satisfaction Increased performance/productivity of occupants We want to accomplish BOTH of these objectives.

8 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.

9 Section 1: Lighting Fundamentals I. Lighting Terms & Basic Calculations II. Lamps Types III. Fixture & Components IV. Lighting Cost Analysis

10 Lighting Terms 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. Lumens Light Level Fixture/Luminaire Lamp

11 Terms Measuring Light 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/Ft 2 ) Also regulated by Energy Codes

12 LPW: Comparing Energy Efficiency LIGHTING EFFICACY LPW FUEL EFFICACY MPG 1000 lumens watts = 50 lpw 150 miles gallons = 15 mpg

13 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.

14 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.

15 Exercise: LPD Calculation Room # Fixture Type # of Fixtures LAMPS # of Lamps per Fixture Wattage per Lamp Input Voltage BALLAST Input Current Power Draw # per Fixture 101 Fluorescent w LPD = Energy (Watts) Area of Room (sf) 15

16 Lamp Types Incandescent Standard - filament type based on pure resistance Tungsten-Halogen Fluorescent Linear Compact (CFL) High Intensity Discharge (HID) Mercury Vapor Metal Halide High Pressure Sodium Low Pressure Sodium Light Emitting Diode (LED) Also other emerging technologies such as Photoluminesence Common lamps are organized into major families, depending on the way the light is produced.

17 Incandescent 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.

18 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.

19 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:

20 Special aspects of newest FL s 6-Light T5HO Fluorescent High Bay Fixture 20

21 High Intensity Discharge (HID) 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).

22 HO Fluorescent vs. Metal halide Chart courtesy of 22

23 LED (Light Emitting Diode) 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. The illustrations above are LED linear fluorescent replacements that are also manufactured in colors.

24 Efficacy of Different Lamps Source:

25 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

26 Symptoms Lamp/ballast end of life 26

27 Luminaires (Fixtures) 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. Components: Housing Electrical connection Lamp holders (sockets) Lamps & ballasts Lenses & louvers Reflector Trim

28 Luminaire Types by Classification Classification by mounting condition (How is the fixture positioned?) Classification by light distribution (Which way is the light going?)

29 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 How they rate in Efficacy, Cost & Life Span Incandescent: Low Fluorescent: Medium LED: High Must look at overall lifecycle cost, based on life span incandescents are cheapest but LED uses less energy and lasts longer. Low cost = low efficiency, low life span (you get what you pay for).

30 Estimating Lighting Energy Use & Cost Two approaches: Top down - At the beginning, to estimate energy used by the different systems Bottom up - After, to determine actual lighting energy use.

31 Top Down Lighting Analysis

32 Bottom Up Lighting Survey

33 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.

34 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.

35 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 Cool White Neutral White Warm White 5000K also called Full Spectrum 4100K 3500K 3000K and below Rules of Thumb Blue/cool light for business/professional setting. Warmer light for home/residential setting. For more info:

36 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.

37 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.

38 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

39 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).

40 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.

41 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

42 Dimming Dimming desirable for many applications Manual dimming o o o Incandescent easy to dim Dimming by resistance device does not save energy o The resistors heat up and the light energy becomes heat energy. Fluorescent - needs dimmable ballast Automatic dimming o By schedule o When unoccupied o When daylight available

43 Scheduling Time clocks Programmable lighting control panels that can integrate to BAS. Prioritization for peak load shaving.

44 Occupancy (and VACANCY!) Sensors 50 Typical Energy Savings (%) Private Office Open Office Conference Room Computer Room Restroom 0 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

45 Occupancy sensor types 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. 45

46 Daylighting 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? Source: Advanced Lighting Guidelines 1993 For Further Info:

47 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

48 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.

49 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.

50 Depreciation

51 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.

52 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.

53 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. Percent Surviving Typical Fluorescent Lamp Mortality Curve Percent Average Life 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.)

54 Reading Assignment for Week 4 -FEMP Sec ( Motors pages ) -Herzog Appendix A: pp