CRES12: Daylight Harvesting & Controls
Presented by: Matthew Malone Northeast Sales Manager
® 20012 Crestron Electronics, Inc. Specifications subject to change. All copyrights and trademarks property of their respective owners.
Update 08-16-12 Crestron Course #: CRES12: Daylight Harvesting & Controls
Crestron Electronics, Inc. is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.
This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
2 Learning Objectives:
By the end of this lecture the attendee will…
1. Define Daylighting and discuss the various benefits & concerns associated with it related to Commercial Architecture.
2. Define Daylighting Harvesting and gain an overview of the various Daylight Harvesting Techniques available.
3. Become familiar with the new changes in the Energy Codes that now require Daylight Harvesting.
4. Understand the terminology & control techniques necessary for a successful Daylight Harvesting system.
3 What is Daylighting?
4 What is Daylighting?
• Daylighting’s objective is…to minimize the amount of artificial light thereby reducing electricity costs.
• Daylighting is… the practice of placing windows or other openings and reflective surfaces so that during the day natural light provides effective internal lighting.
• Daylighting can also…lower HVAC costs. Properly controlled natural daylighting generates hardly any heat compared to its electrical lighting counterpart.
5 Daylighting Techniques
• Light Shelves • Light Wels • Sky Lights • Light Pipes Sky • Vertical Glazing Light Light Electric Light • Glass Interior Shelf Walls • Photovoltaics Light Light Glass Pipes Vertical Wells Walls Glazing Photo- voltaics
6 Daylighting Benefits
7 Benefits of Daylighting:
• Full Color Spectrum
8 Benefits of Daylighting:
• Full Color Spectrum • Aids bodies natural Circadian Rhythms & prevents Seasonal Affective Disorder
9 Benefits of Daylighting:
• Full Color Spectrum • Aids bodies natural Circadian Rhythms & prevents Seasonal Affective Disorder • Saves Energy
10 Benefits of Daylighting:
• Full Color Spectrum • Aids bodies natural Circadian Rhythms & prevents Seasonal Affective Disorder • Saves Energy • Improves end-user satisfaction/performance & consumer sales
11 Benefits of Daylighting:
• Full Color Spectrum • Aids bodies natural Circadian Rhythms & prevents Seasonal Affective Disorder • Saves Energy • Improves end-user satisfaction/performance & consumer sales • High Demand, High Value, Corporate Image
12 Daylighting Concerns
13 Daylight Concerns:
• Sky Factor
Clear Sky Partly Cloudy Overcast
14 Daylight Concerns:
• Sky Factor Clear Sky Partly Cloudy Overcast
Amount of sun varies every day Number of days of sun per year varies with every city ‘Sunnier’ cities will have higher ROI and faster payback than others Control system needs to be commissioned appropriately for the climate type Commissioning requirements should be included in the programming scope and the CSI specifications to suit the clients expectations
Example: Miami has quickly passing clouds, select a slower ‘Response time’ (2min.) Seattle has slowly passing clouds, select a faster ‘Response time’ (30 sec.)
15 Daylight Concerns:
• Sky Factor
• Building Orientation
16 Daylight Concerns: South-facing windows are most advantageous for daylighting and for moderating seasonal temperatures. They allow most winter sunlight • Sky Factor into a building but little direct sun during the summer, especially when properly shaded. • Building Orientation North-facing windows are also advantageous for daylighting. They admit relatively even, natural light, producing little glare and almost no unwanted summer heat gain.
Although east- and west-facing windows provide good daylight penetration in the morning and evening, respectively, they should be limited. They may cause glare, admit a lot of heat during the summer when it is usually not wanted, and contribute little to solar heating during the winter.
17 Daylight Concerns:
• Sky Factor
• Building Orientation
• Obstructions
18 Daylight Concerns:
• Sky Factor
• Building Orientation
• Obstructions
Understand that ROI for a project in a city with buildings in close proximity will vary from the same building in a rural setting or in a less crowded environment
19 Daylight Concerns:
• Sky Factor
• Building Orientation
• Obstructions
• Solar Heat Gain
20 Daylight Concerns: Low SHGC glass (Solar Heat Gain Coefficient) • Sky Factor Low U-Factor Glass (Heat Flow through • Building Orientation the window)
• Obstructions Low AL (Air Leakage)
• Solar Heat Gain Install Manual or Motorized Shades !!!!!!
Install multiple layers of shades
21 Daylight Concerns:
• Sky Factor
• Building Orientation
• Obstructions
• Solar Heat Gain
• Glare
Too permanent, ruins façade of the building
Makes it hard to work 22 Daylight Concerns: Size windows properly
• Sky Factor
• Building Orientation
• Obstructions Install Manual or Motorized Shades !!! • Solar Heat Gain
• Glare
23 Daylight Concerns: Install Manual or Motorized Shades !!! • Sky Factor Consider 2 layers of shades to correctly • Building Orientation manage daylight: Summer solstice, southern latitude - translucent fabric • Obstructions - black out shades • Solar Heat Gain Solar Tracking Install manual override • Glare Integrate with lighting control & AV scenes within the room Winter solstice, southern latitude
24 Daylight Concerns:
• Sky Factor
• Building Orientation
• Obstructions
• Solar Heat Gain energy savings > the price tag? • Glare
• What is the Return on Investment (ROI)?
25 Daylight Concerns:
• Sky Factor “What is the true ROI for Daylight Harvesting?”
• Building Orientation
• Obstructions
• Solar Heat Gain Part 1 – The cost ($) of the Daylight Harvesting System • Glare Part 2 – The value ($) in Energy Savings Part 3 – The value ($) of Happy Tenants…priceless • What is the Return on Investment (ROI)? > $0.00 then a Positive Return on Investment !
26 Daylighting Study
27 In a recent study by Lawrence Berkeley National Labs they attempted to answer two very important questions related to Daylight Harvesting …
“Where are the Primary & Secondary Daylighting Zones located?”
“How much Energy is saved in each Zone?”
28 Daylighting Study:
Vertical Glazing: Primary & Secondary Zones
9’
6’ Primary Secondary Third Primary Secondary Zone Zone Zone Zone Zone 0 to (10-15’) (10-15’) to 25’ 25’+ 0-11’ 11-31’
Example 1 Example 2
29 Daylighting Study:
Horizontal Glazing: Primary & Secondary Zones
Skylight Larger quantities of light than Vertical Glazing, but lacks views to the exterior 35° 35° h Cannot be used for LEED
Secondary Secondary Indoor Environmental Zone Zone Quality Credit 8.2 h x 70% h x 70% Primary Zone
30 Daylighting Study: Energy Savings
In a recent study by Lawrence Berkeley National Labs, they compared the energy for one year from a space with daylight harvesting to a space without daylight harvesting and found…
Example B: LBNL Study - 9’ Glass Walls, all 4 sides of the building - Low Partition, Open Work Stations - Daylight Dimming Techniques used
Primary Zone Energy Savings: West facing walls - saved 30% NW & SW facing walls - saved 50- 60% 9’ 30-60% 10-40% Secondary Zone Energy Savings: Energy Energy West facing walls - saved 10% Savings Savings NW & SW facing walls - saved 25- 40% 0-11’ 11-31’
31 What is Daylight Harvesting?
32 What is Daylight Harvesting?
A control system used in sustainable architecture that reduces the use of artificial lighting with electric lamps in building interiors when natural daylight is available, in order to reduce energy consumption.
33 Daylight Harvesting Techniques
34 Daylight Harvesting: Open Loop Systems
Open Loop Sensor: Example #1 Skylight • The photosensor detects the amount of available daylight only • It can be positioned: • on the building's exterior wall or roof • or inside the building facing the skylight 35° 35° h
Typical Open Loop h x 70% h x 70% Photosensor Example #1
35 Daylight Harvesting: Open Loop Systems
Open Loop Sensor: Example #2 • The photosensor detects the amount of available daylight only • It can be positioned: • on the building's exterior wall or roof • or inside the building facing the skylight • or inside the building facing the window h • Allows multiple zones of fixtures to be controlled with a single photosensor
Typical Open Loop h 2h Photosensor Example #2
36 Daylight Harvesting: Closed Loop Systems
Closed Loop: Typical Closed Loop • The photosensor detects the combination of Photosensor daylight and electric light • It should be positioned: • away from direct sunlight • away from direct artificial light • where it can measure reflected light off a surface from both the natural and h artificial light • Allows you to define a single set point and vary the zones to achieve it • Each independently controlled zone requires h 2h a photosensor Example
37 Daylight Switching Vs. Daylight Dimming
38 Daylight Harvesting: Switching or Dimming?...
Daylight On/Off Switching - once daylight level is reached, lights switch off (Ex: 100% On or All Off) Recommended for: Day lit spaces with non-stationary tasks, where the task is the floor (ie: Corridors, Atriums) Day lit spaces shielded from view by stationary workers so it is not distracting
Advantages… Disadvantages… • Lower initial cost • Only 2 levels of light • Simpler design • Lower energy savings • Easier to commission • Abrupt changes in light levels are considered irritating
39 Daylight Harvesting: Switching or Dimming?...
Daylight Bi-Level Switching – 2+ levels of daylight can be reached. (ex: 100% / 66% / 33% or Off) Recommended for:
Day lit spaces where non-detailed tasks take place (ie: warehouse, factory, gym) Day lit spaces where switching is not distracting
Advantages Disadvantages • 3+ levels of lighting • Somewhat distracting • Cheaper than full dimming • Additional ballast(s) & • Additional energy savings wiring needed • Additional cost than switching
40 Daylight Harvesting: Switching or Dimming?...
Daylight Dimming – Unlimited levels of daylight can be reached.
Recommended for:
Day lit spaces where detailed tasks are being performed (Classrooms, Labs, Office Spaces) Day lit spaces where exact fc levels are needed
Advantages Disadvantages • Exact fc level can be • $ Dimming ballast(s) needed maintained at all times • Commissioning may require • Most comfortable for clients more time • Highest energy savings
41 Daylight Harvesting Codes
42 Daylight Harvesting Codes: ASHRAE 90.1 - 2010
ASHRAE Standard 90.1 2007 2010 Changes 43 Daylight Harvesting Codes: ASHRAE 90.1 - 2010
Daylighting Requirements: . Developed in conjunction with Title 24 . Requires the installation of skylights when appropriate
Daylit areas must have multi-level control: • At least 2 levels of output, 0-35% & 50-70%, All On • Or Continuous Dimming Top Lighting: (Skylights & Rooftop Monitors) - Applied if daylight area under skylight and rooftop monitors is >4000 ft2 Side Lighting: (Vertical Glazing) - Applied if sidelit area is >1000ft2
44 Daylight Harvesting Codes: ASHRAE 90.1 - 2010
Lighting Power Incentives: . When mandatory & advanced lighting controls are met in a space, additional lighting power (LP) is allowed:
Additional LP = Lighting Power Under Control * Control Factor
. There are various charts listing Control Factors, several of which refer directly to Daylight Harvesting
. Therefore, there is additional lighting power allowed per code if Daylighting is incorporated into various spaces
45 Daylight Harvesting Codes: ASHRAE 90.1 - 2010
46 Daylight Harvesting Codes: ASHRAE 90.1 - 2010
Additional 20% W/ft2
47 Daylight Harvesting Codes: ASHRAE 189.1 - 2010
. Automatic Lighting Controls - expanded to include: - daylight harvesting - manual-ON and bi-level occupancy sensing - bi-level switching in some stack and egress and outdoor applications. . Submetering: Major building systems such as HVAC & lighting are required to be submetered and the data fed to a data acquisition system for storage and later retrieval. . On-Site Renewables: Buildings must provide for future installation of on-site renewable energy systems. . LPD: Lighting power densities capped at 90% of those in 90.1-07 . Peak Load Shedding: In addition, buildings must contain automatic demand-response systems enabling peak electric demand to be reduced by at least 10%.
48 Daylight Harvesting Controls & Commissioning
49 Daylight Harvesting Controls: Photosensors
Photosensors Used to measure the quantity of daylight in the space then determine the amount of dimming or switching required to maintain the design work plane illuminance level.
Typical Open Loop Typical Closed Loop Photosensor Photosensor
• 0-10V signal • 0-10V signal • 3-300, 30 to 3000, or 60 to 6000 • Measures 0-70 footcandles footcandle range
50 Daylight Harvesting Controls: Direct Method vs. Processors
Direct Method - Wiring the lighting ballast & photocell together. Typical for some open-loop systems. Extreme limitations in control capability. Not recommended, not code compliant.
Processor Method - A processor is the brains of a Daylight Harvesting control system. It receives data input from the photocell and then sends a signal to: - the ballast or light fixture to turn on/off/dim - keypads and/or touchpanels for override - facility energy management & monitoring system - shade system * It also makes it easy to commission and change the settings of the photocell remotely as needed.
51 Daylight Harvesting Controls: Ballasts
Switching Ballasts: . Designers may need to add additional ballasts if fixtures are going to be utilizing inboard/outboard switching for multiple lamps. * One and Two lamp fixtures will not comply with the new ASHRAE 90.1-2010 code requirements and will therefore they will have to be continuously dimmed.
0 – 10V Dimming Ballasts: . These ballasts are designed with control wires to easily communicate with Daylighting system processors and continually dim a group of fixtures on the same zone as programmed. . 100-1% dimming ranges
DALI Ballasts: . Designed with DALI control wires that are designed to allowed for unique addressability of each ballasts so that they can be dimmed individually or as a group in the same zone.
52 Daylight Harvesting: Open Loop Commissioning
Open Loop Systems…
. The single adjustment setting on a proportional control can be set at any time that daylight is present. Skylight . However, adjustment should be made at a time when the daylight distribution is representative of what it should be. . Do not commission during a period when direct sunlight is streaming in, if that is not the norm. . Optionally set a minimum dimming level (see next slide)
53 Daylight Harvesting: Closed Loop Commissioning
Closed Loop Systems…
. Minimum dimming level is set (optional) . Some may find it distracting if the lights actually switch off and on . More of an issue in classrooms and offices than in large public spaces
. The desired light level is set by dimming Vertical or switching the electric lights until the Glazing desired light level is achieved. . Note: Take a light meter!
54 Daylight Harvesting: Commissioning Terminology
The following settings are common parameters when configuring the operation of a daylight harvesting system:
Response Time – defines how quickly the system reacts to changes in light levels Minimum Dim Level – defines the lowest level a dimmer may output (can be used to prevent the lights from turning completely off when dimming) Dim Level To Photosensor Relationship (Open-Loop) – defines dimmer output levels in relationship to open-loop photosensor readings Desired Light Level (Closed-Loop) – defines the desired light level in the space Photosensor Range – set photosensor fc range (3-300, 30-3000, 60-6000, etc.) (Sensor voltage output to light level relationship needs to be defined in the system)
55 To Think About…
. 2010 became the year for mandatory Daylighting control requirements nationwide (enforcement though will remain per city & state) . There are various techniques available to incorporate daylight harvesting into a commercial project . The benefits of daylight harvesting (including energy savings) outweigh any of the prior concerns due to the new technology, programs, & simple commissioning tools that are now available from various manufactures . The only way we will truly reach future sustainable goals is to integrate Daylight Harvesting into more than just lighting, and then and look at the big picture…
…Integrated Building Technology.
56 This concludes the 1 hour Crestron AIA Continuing Education Seminar on:
CRES12: Daylight Harvesting & Controls Thank You.
Please feel free to complete the course evaluation forms.