Daylight Analysis Tool, Powered by SkyCalc® of these absorb considerable amounts of both daylight...

: User’s Guide

SunLite Calc Users Guide - Version 1.0 - March 2012

A step by step guide to operating version1.0:

ü Establishing your settings; including labor rates and markupsü Basic building entry procedures and definitionsü Description of reports and analysis outputs availableü List of support materials for reference

Introduction

Welcome to SunLite Calc, the web based daylighting analysis tool specifically forthe innovative SunLite Strip series of skylights from Butler Manufacturing.SunLite Calc is powered by SkyCalc, the industry recognized energy calculatordeveloped by Heschong Mahone Group, an independent research andconsulting firm specializing in building design, construction technology, policydevelopment and program design.

It is our intent that with accurate inputs, you can responsibly promote aneffective array of SunLite Strip units on new or retrofit Butler Buildings thatfeature MR-24, CMR or TLS standing seam roof systems, coupled with effectivelighting controls to reduce your clients electric lighting expense while improvingthe overall building aesthetics, employee productivity and customer satisfaction.

Getting Started

SunLite Calc is an online tool accessible through MyBuilderNet.com and is onlyfor Butler Builders and their clients. It can be used on a number of device andweb browser configurations, including PCs, Macs, iPads, iPhone’s, Androids etc.

To get started, login to your MyBuilderNet account. While on the main page,you will see the link to SunLite Calc, click there.

Please review the disclaimer upon entering the site and click ‘OK’ to proceed.

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User’s Guide

SunLite Calc User’s Guide - Version 1.0 – March 2012

Once inside, it’s best to start by establishing your specific user settings.

Settings

Under settings, you have the ability to define different labor rates and markupsfor different jobsite conditions, clients, in town vs. traveling crews, etc. in theprivacy of your office and not while in front of your client.

Note: The unit costs listed represent the STANDALONE unit price for eachvolume tier, without freight and taxes, and should be used for budgeting

Before entering your buildinginformation, be sure to defineyour user settings by clicking here.

: User’s Guide


purposes only. Pricing may vary and you should always use project specificpricing.

Skylight Markup percentage will be applied to the unit prices listed in theSkylight Cost table only. Your install rates defined below should include yourmarkup on labor.

Installation rates will vary per project and also by unit description (Upslope,downslope, continuous and stand alone), contact your product specialist forappropriate man hour estimating guidance.

When complete, click on ‘Create Markup Code’ to save your settings. Select ‘IsDefault’ to select the markup code you prefer as the default.

Recent Projects

SunLite Calc allows the user to save and later search for existing projects. Besure to name each project something will be distinctive should you need to recallit later.

Project Tab

Enter a Project Name and description that will be memorable as you will often havenumerous alternates and revisions. When selecting nearest climate, choose one thatshares climatic characteristics with your project location. Keep in mind we will beupdating the number of cities as we continue to develop this tool. At a minimum youshould be able to accurately model a location located within the climatic zones asdescribed by ASHRAE. We’ve been told international cities will soon be available aswell, we will keep you posted.

Click on ‘Create Project’ when complete.

Product Tab

Version 1.0 only features one daylighting option, SunLite Strip so that decision ismade for you!

Note: By selecting ‘product details’, you will expand a window that listseach of the key performance measures for the standard dual glazed,stamped prismatic acrylic lens that SunLite Strip currently features. IF youreceive a custom quote for an alternative glazing, DO NOT use SunLite Calcas the results will not be accurate! Contact your product team to see if analternate version of SkyCalc can be run on demand.

User’s Guide


For Installation Code, select the desired setting you defined earlier if differentthan your default setting.

Similar to the Product Definition, there is only one unit length to define inversion 1.0. We appreciate the field benefits of being able to connect multipleunits for each roof penetration, but to begin your model, we’ve found it easier tofirst determine the appropriate amount of daylight you want to achieve and thendetermine the best layout as your building plans develop.

Select ‘Next’ when complete to advance to the next tab.

Note: At several points while entering data for a model, you mayexperience screens ‘flickering’ or otherwise transitions from screen to screenthat aren’t entirely smooth. In most cases you’ve done nothing wrong, it’ssimply the complex calculations taking place behind the scenes, pullingdata from a large number of tables.

: User’s Guide


Building Tab

The first selection on the Basic Inputs tab is Building Type. Select from thelist the end use that most closely matches your projects. Clearly this listdoesn’t cover each and every type of building out there. What the authorsof the program tried to do was model distinct schedules and intensities ofuse for people, equipment, lighting, heating and cooling.

Next, enter the square footage of the building or section of building you’d liketo model, followed by eave height. Please keep in mind the calculations in theprogram assume a simple, one-story rectangular floor plan based upon totalfloor area. SunLite Calc should only be used to evaluate the daylit areas inthe buildings. Rooms or areas of buildings with substantially different uses,configurations, schedules or light levels should be evaluated separately.

Building Wall Color (Interior) deals specifically with reflectance of the interiorsurface so select the one that most closely matches your project.

Partition/Shelving Type is an area to communicate obstructions that wouldinterfere with the distribution of daylight. It assumes the obstruction you defineruns evenly and consistently throughout your building. Each of these absorbconsiderable amounts of both daylight and electric light, and the lighting powerdensity calculations are adjusted accordingly. A building which is partiallyopen and partially filled with racks should be evaluated as two separatespaces. You may find that these different spaces produce different energysavings and may require different daylighting designs.

Important Note: From this point forward information will be split intotwo areas; basic and optional. Basic Inputs represent the bare minimumamount of information required to perform an analysis. Optional Inputsare for additional information you may have specific to a project thatwould vary

User’s Guide


Finally, the calculation of illumination levels and lighting power densities for areaswith shelving or partitions is a rough approximation based on the ‘Floor Cavity’approach of the lumen method. The method loses accuracy as the shelves gethigher in proportion to ceiling height. For greater accuracy, we recommend thatyou use a lighting design program to determine more precise values for lightingpower densities for a given illuminance target. These can be entered under theoptional inputs tab for Lighting.

Optional Inputs- Building

The Building section tab, Optional Inputs describes in greater detail the buildingcharacteristics that are used in SunLite Calc analysis. Keep in mind that byBuilding we mean daylit space that is analyzed, which may actually only be aportion of the actual building. As a default, SunLite Calc assumes each buildingis a single story rectangle twice as long as it is wide. You can override thisassumption by revising the building width. The length will be recalculated basedupon the overall area of the building. This is also the place to revise ceiling, wallfloor and shelving reflectances if you have more accurate values.

Lighting Tab

This section is asking you to define the existing or proposed electric lightingsystem and its controls. SunLite Calc calculates a default lighting power densityfor your system, based on the footcandle setpoint, the fixture type and otherbuilding characteristics.

The Lighting System pull down menu defines the lighting type for generallighting. Only one system can be modeled at a time. When you select a specificlighting system, it is used to determine amount of lighting power needed toachieve your target illuminance. The pre-defined lighting systems in SunLite Calcare:

• Open cell fluorescent- deep cell parabolic fixtures containing T-8 fluorescentlamps and electronic ballasts.

• Lensed fluorescent – lensed troffers containing T-8 lamps and electronic ballasts• Direct/Indirect fluorescent – suspended fixtures with reflector grid, with 39%

uplight and 32% downlight, with T-8 lamps and electronic ballasts• Indirect fluorescent – suspended luminous bottom indirect fixtures 66% up light

and 12% downlight with T-8 lamps and electronic ballasts

: User’s Guide


• Industrial fluorescent – industrial strip fixtures with a porcelain enameledreflector, T-8 lamps and electronic ballasts

• High Bay Metal Halide – high bay intermediate distribution ventilated reflectorwith clear metal halide lamp and magnetic ballasts

• Low Bay Metal Halide – low bay lensed bottom reflector unit with a clear metalhalide lamp and magnetic ballasts

• High Bay HPS – Same as High Bay Metal Halide but with clear HPS lamp• Low Bay HPS – same as Low bay Metal Halide except with clear HPS lamp

Note: These are the standard lighting types modeled in SkyCalc, it is likelythat we will add to this list in future releases. However, if you would like tomodel a different lighting system, the original version of SkyCalc allows foruser defined systems. You will need specific light distribution metricsincluding lumen intensities. The format of this table and the source formore data for other fixture types can be found on page 443 of the 8th Editionof the IESNA Handbook. Your product teams can work with you to inputthese values into the public version of SkyCalc for your use.

You can also select ‘View Systems’ to see an example of each type. Click on‘View Systems’ again to return to Basic Input mode.

Lighting Setpoint is expressed in footcandles and is a critical input to yourcalculations as it triggers your lighting controls to adjust or turn of lighting oncethis desired level is reached. We’ve included a ‘Rules of Thumb’ chart with somebasic parameters often seen for lighting setpoint per building end use, that can beaccessed by clicking on the ‘ i ‘ button (see below).

User’s Guide


Light Fixture Height is expressed as an average height given the rise in slope ofyour building.

Lighting Controls are without doubt as essential to your electric lighting savingsas the skylights, because if you won’t see savings unless the lights turn off. Thatsaid, SunLite Calc has an extensive list of pre-defined lighting controls. The listhas two sections: Switching Controls, which are common to all lightingtechnologies and Dimming & Hi/Lo Ballasts, which are specific to a certain typeof lighting technology. Therefore you’ll notice that your choice of controls mayvary depending on the type of lighting system.

The Lighting Controls pull down menu selects the lighting control strategy. TheLighting Control Graph below the pull down menu illustrates the relationshipbetween the lighting power required by the electric lighting system and theavailable daylight inside the building for the selected control strategy. It alsoindicates the current illumination target measured in footcandles. Note: One ofthe options in the pull down menu is No Lighting Controls. This allows youto illustrate just the heating and cooling energy impacts of skylightswithout controls.

Select the i button to expand theLighting Setpoint Rules of Thumb

: User’s Guide


Optional Inputs- Lighting

This section describes the characteristics of the electric lighting system and it’sschedule of peration. The operation schedule is important because SunLite Calcassumes that the lighting control system turns down the electric lighting whendaylight is available only when the lights are scheduled to be on.

The Lighting Power Density, in Watts per square foot, is calculated from thelighting setpoint, the type of lighting system, and the shape and reflectances ofthe building and it’s shelving. We’ve included a chart with common lightingpower densities grouped by end use for your reference, simply click on the ‘ i ‘button. Note: Lighting Power Density is a metric used to qualify for EPActtax deductions and other incentives.

The Lighting Control Graphillustrates the relationshipbetween electric lighting power,available daylight and triggerpoints when lights shut off basedon your Lighting Setpoint

User’s Guide


Task Height describes the height of a horizontal task surface above the floor(such as a desk surface). If the primary activity of the space is walking (such as alobby) then the task height would be the floor, measured at zero, Retail facilitiesoften consider the task height at eye level, etc.

Fraction Lighting Uncontrolled describes the fraction of the ambient lightingsystem that is not controlled in response to daylight (might be operated on anemergency circuit that leaves them on at all times.

Lighting Schedule is the fraction of lighting to be used during a given hour ofoperations, these can be revised via the lighting schedule pull down menu.

Room and Luminaire Depreciation describes the percentage of light that will beavailable from the electric lighting system in several years time, as compared tolight from a new fixture with clean surfaces. This is already accounted for in theprogram based on the useful life of each lamp technology.

Utilities Tab

SunLite Calc estimates the energy cost savings (or increases) for lighting, heatingand cooling and sums them up to give you a net impact that can be expected inthe buildings energy costs. SunLite Calc assumes that the buildings electricallighting and cooling systems use electricity and heating systems also useelectricity or other fuels.

Enter the average yearly cost of electricity per kWh. This can be found bydividing the total electricity costs on a bill by the total consumption of electricityin kWh for that period. This cost is typically higher than the quoted usage costper kWh of electricity because it includes other charges, such as peak electricaldemand charges.

: User’s Guide


Heating Fuel Units pull down menu allows you to specify the cost of heatingfuels in units the supplier provides, eliminating the need for unit conversions.

Optional Inputs- Utilities

The HVAC section describes the operating characteristics of the HVAC systemspecified on the basic inputs tab. The program models HVAC based on a 1 or a0 schedule. When the schedule is ‘1’, the specified heating and coolingsetpoints are maintained in the space, when the schedule is ‘0’, the setbacktemperatures apply. You can specify an economizer which brings in outside airto provide cooling when the outside air is cool enough.

Results Tab

Congratulations, you have completed the required inputs in order to model yourbuilding!

You’ll notice a new area below the previous menu of tabs that display theskylight count, effective skylight to floor %, annual savings and the calculateresults button. There are a few things to pay attention to here:

Skylight Count this is where you enter the number of unit skylights to model.Next to that is the icon for the unit description pop up window, where youdetermine the orientation of the total number of units you’re modeling.

User’s Guide


Note: Based on the size of your building, there are a minimum number ofskylights required for uniform daylight distribution. The analysis providedby this tool requires uniform distribution. If the number you select is lessthan the number required for uniformity, a red box will appear under theresults bar stating the minimum number needed.

If you are modeling your facility for a certain ESFR or effective skylight to floorratio, you can also determine the number of unit skylights by using the slidebar.

Filling in the unit description boxis required before you generatethe Payback Analysis report as itrelates to the labor amount you’vedefined in settings for each type ofunit.

Keep in mind, the total number ofunits must match your allottedunit description.

: User’s Guide


Annual Cost Savings displays the estimated net savings (or loss) of the buildingyou defined and calculated results for.

To the right of the savings is the Calculate Results button, which starts theengine that calculates the results of the inputs you’ve defined. There’s literallyhundreds of calculations performed the moment you click!

Note: The Annual Cost Savings displayed only refreshes when you CalculateResults, NOT after each change you make. So it’s very important that youre-calculate after changes in order to get accurate results.

Below the results bar are four reports that have been generated for you eachtime you calculate results: Table Results, Graph Results, Climate Results andPayback Analysis. Let’s look at each report in detail.

Table Results

Table Results summarizes the key information used to calculate energy savings fromskylights in tabular form. This tab also presents the energy and cost savings results for theskylighting system defined from the inputs. Most of the terms have been definedpreviously in this guide, those specific to this report are:

Unsure what % is right for yourfacility? Click on the ‘i‘ button andrefer to the rules of thumb chartgrouped by end use.

User’s Guide


Full Daylighting: the number of hours that the interior daylight levels were above thelighting setpoint.

Overall Skylight System tVis: The fraction of the light from the sky that leaves theskylight well. It is a product of the VLT (Variable Light Transmission) of the glazing, the wellfactor, the dirt factor and the safety screen or grid factor. (All of these are predefined forthe SunLite Strip and locked in)

Skylight CU: The fraction of light leaving the skylight well that reached the work plane,accounting for geometry and interior reflectances.

The Savings from Design Daylighting System table itemizes the savings fromthe proposed skylighting system, as compared to the same building withoutskylights for lighting, heating and cooling. Note: A negative figure means thatthe skylighting system will result in more energy used than saved. It’s notuncommon for a well designed skylighting system to have negative values forheating and/or cooling, but this is typically overshadowed by substantiallyhigher lighting energy reductions. If the total eSFR gets too large, you willexperience diminishing returns.

Graph Results

These graphs could also be called ‘optimizers’ in that they depict how close theeSFR is to the optimum design condition. With all other variables held constant,they vary the eSFR from 0-12%. The resulting performance curve is plotted forboth whole building energy savings and dollar value of those savings. Theperformance fo the proposed design is also indicated.

If you were to change the physical characteristics of the skylights, the daylightingcontrol system, energy costs, or details about the building and its operation,then the shape of the curves would change.

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At this point you can enter a new number of skylights to analyze based onmaximizing your clients return. Don’t forget to hit the button in orderto re-run the calculations!

This graph speaks to therelationship between the amountof heating and cooling isgained/lost vs. the amount savedon lighting. This seemscounterintuitive to some. If so,refer to the DOE report listed inSunLite Calc under the‘Downloads Tab”

User’s Guide


Climate Results

The Average Daily Foot Candles graph displays the average indoor daylightilluminance in foot candles for each hour in each month for the SunLite Strip forthe project you’ve defined.

This gives an indication of how bright it will be inside from daylight only. Thecalculations are based on the average weather conditions for each hour of eachmonth, using typical weather data (TMY) for the location selected. Of course, onany given day the value may be higher or lower, depending on actual conditions.The shading of the graph, which is relative to the Lighting Setpoint you definedearlier, indicates the hours during which the electric lighting system will becompletely on, at minimum power, or somewhere in between.

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Payback Analysis

The final element of SunLite Calc is to take the analysis completed, applyestimates for product cost and labor and balance that against the energy savingsto formulate a simple Payback Period.

At the top of the report, you’ll see a recap of the project you’ve defined (setpoint,roof u-factor, lighting controls and fixture height), an estimate of the unit costsfor the number of SunLite Strip units you’ve elected and the labor you’veestimated to install them.

Why do we call it a simple Payback Period? Perhaps it’s easier to explain whatthis number does not include; any increases in utility cost, net present value ofthe energy savings, EPAct tax deductions, utility company rebates (peak shaving,etc.), increased worker productivity and satisfaction, increased sales, betterlooking merchandise, LEED point contribution, etc.

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