Advancements in Lighting—A Peek at the New Lighting Requirements for ASHRAE/IESNA Standard 90.1-2010 Applicable to Retailers (Text Version)
Below is the text version of the Advancements in Lighting—A Peek at the New Lighting Requirements for ASHRAE/IESNA Standard 90.1-2010 Applicable to Retailers Webcast, presented on October 13, 2008. Eric Richman from Pacific Northwest National Laboratory was the only presenter. This presentation provides details on how national codes apply now and in the future to retail facilities. You can also view the slides for this presentation (PDF 390 KB). Download Adobe Reader.
(Slide name: Advancements in Lighting)
Hello, I'm Eric Richman and today we're gonna talk about some advancements in lighting. A look at the new requirements that are gonna be in the ASHRAE IESNA standard 90.1 that might apply to retailers and their activities.
(Slide name: Standard 90.1 Basics)
So, looking at a little bit of basics here on the standard itself, for those who are not familiar with it, it is jointly sponsored by ASHRAE and IESNA. The 2007 version is the current published version. This may change, of course, with time. Many states, of course, adopt older versions. So you may be dealing with a previous version of the standard. But we wanted to give you an idea of the new requirements so you'll see what's coming up.
There are many state specific codes. And there's another national code, the IECC. The IECC and some of those state codes are based on the requirements here in 90.1. So it may be applicable, even if your state has not adopted them ASHRAE code. IECC itself references 90.1 as a separate compliance option. The 2004 version of the 90.1 standard is also referenced in NFP 5000, which is another code that might be adopted in your state.
(Slide name: Review of Changes for 2010 — Caveats)
Just a little — some more background. The changes that you're looking at here that we're gonna discuss are, as of this date, essentially changes that are either approved as addenda or proposed as addenda and going through the review process. Or under consideration by a subcommittee. And I mention that just to make sure that you realize the 2010 version is not out yet, but these are what we believe will be in that version when it comes out. So it's just kind of a heads up.
Again, when they become part of the 2010 standard they will only be effective to you and your facilities, when they're adopted by your jurisdiction. Your state or your county, etcetera. And also, because a lot of the development of standards work does come from 90.1 and its body of members, you will probably soon see versions of these requirements in IECC and other state codes as we mentioned before.
(Slide name: Basic Lighting Requirements)
One more little bit of background on the basic lighting requirements in the 90.1 standard itself. As you go through it for compliance you'll notice there are three basic sections. One is on manufacturer requirements. And these are mostly controls, some switching and a little bit of efficiency. These are the requirements that have to be met, specifically to those language requirements.
Two other sections, one on interior lighting power limits and one on exterior lighting power limits. These both are based on the idea of a total connected power that you're planning to put in the building and an interior or exterior lighting power allowance that's based on the standards, requirements. Your total connected providing power needs to be less than the allowance. A very simple straightforward comparison.
For interior there are two different methods of compliance — whole building and space by space. In the exterior there are some tradable and non-tradable sections and parts. And we'll discuss those briefly as well.
What you'll see today are changes in controls and changes in some of the exterior requirements. And I just wanted to highlight those. There are some new day lighting occupancy sensor and incentives. New for the 2010. And for exterior you'll see an expanded set of requirements. So we'll go over those also in detail.
(Slide name: Occupancy-Based Control Additions)
One of the first changes that would be applicable to retailers is an expansion of the current requirement for occupancy based control. What this requirement does is essentially require occupancy sensor control in place of manual switches in certain rooms. And the added points here in red are those space types that are gonna be added to the 2010 version. So there's additional control required there.
Just briefly, some of them are kind of clarifications. For example, training rooms is added to conference meeting rooms. Similar function type. Lecture halls are added to classrooms. But there are a series of new space types. Storage and supply rooms. Rooms for copying, photocopy rooms. Office spaces, but only up to 250 square feet. Restrooms and dressing rooms. The exceptions haven't been changed but they have been moved from other sections to basically clarify. So the exceptions that would apply here are listed as well. So that's one of the new requirements. A lot of these spaces, of course, will exist in retail spaces. So it's important to understand that these will be required in the future.
(Slide name: Occupancy Manual-on Requirement)
Another new requirement is that if you have an occupancy sensor control put in to meet the requirements of the standard it must be a manual on type of device. Most typical occupancy sensors are automatic on, automatic off, which is what we're used to seeing. However, the automatic on feature can inhibit energy savings sometimes in that it'll come on when you really don't need it to come on. And then you'll wait for between 10 and 30 minutes to go off. And that can be a waste of energy.
Also there's an issue of false starts from the sensor reading someone who really isn't entering that space. So the new requirement is it must be a manual on. You have to manually turn it on. But then it will automatically turn off once you leave the area. And of course, because of this type of control there were a few space types where it may not be practical to have manual on. And those have been listed here as well. Corridors and stairwells where it might be a safety issue. Restrooms where it's just not practical in some cases. Entrance areas and lobbies where you don't want lighting going on and off at odd times. And any other place where there's possibly a safety or security concern are exempted.
(Slide name: Zonal Exterior Power Allowance Revision (1st slide))
The exterior lighting, as we mentioned, has been translated to a four zone system. Want to talk about that a little bit. Initially there were just one set of requirements for exterior applications. But there is some work being done recently, a model lighting ordinance that IESNA and others have been working on that recognizes the fact that in certain areas, depending on the ambient light around you, your needs for contrast are lower. And therefore, you don't need as much light to illuminate certain areas and surfaces.
And there is a set of zones that have been based essentially on the mode, the MLO ordinances. Which described areas in four different classifications. The lowest lighting need spaces would be developed areas of national parks, state parks, rural areas, etcetera. Where there isn't much light to begin with so you don't need much light for contrast.
Moving up from there, zone two area is consisting of residential zoning, neighborhood business districts, etcetera. Where more light is needed. There's a catchall in between for everything else. And zone four, which is the really high light environments such as major metropolitan areas where there's a lot of existing ambient light. So you need more light to provide contrast for good visual purposes.
So with those four zones in mind….
(Slide name: Zonal Exterior Power Allowance Revision (2nd slide))
…what has happened is the existing exterior power allowances have been revised to a four zone system. And the basic note here, a lot of detail I won't go into. You have the information here. But you'll notice that the existing values that are the black text in zone four, are what were in the standard previously, in the 2007 version. And as you go down in lighting requirement, zone three to zone two to zone one, you'll see for most spaces there's less allowance. That isn't always the case but in most cases less allowance. Again, because you don't need as much light.
At the same time you'll notice there have been some additions, things that were not in the table initially. Such as pedestrian tunnels and landscaping at the bottom of the slide, for example. That have been added because these are items that probably should have been in before and have now been included. To make sure that all areas in the exterior have been covered.
(Slide name: Zonal Exterior Power Allowance Revision (3rd slide))
And the slides you just saw were for tradable surfaces. This is another slide for tradable surfaces. And of course, by tradable surfaces we mean those where you can trade off the lighting power density allowance between applications. So for example, if you have a lot of main entrance or if you have a lot of entrances, a main entrance and a lot of other doors, and you have a parking lot, you can trade some of the wattage from your parking lot if you don't need it to do a better job of illuminating your main entrance. Those are all tradable surfaces.
(Slide name: Zonal Exterior Power Allowance Revision (4th slide))
If we look at the final part of the table, these are the non-tradable surfaces that recall from the previous version, the standard 2007. These are a use it or lose it amount of allowance. The wattage allowed can only be used for this application. It cannot be traded anywhere else. These are special considerations, a lot of them driven by safety requirements. So for example, you'll notice a lot of these are the same across the board. There's no difference depending on which zone you're in. Again, driven by mostly other safety requirements.
So that covers what's going to happen with the exterior lighting for 2010.
(Slide name: Daylighting Changes)
Let's move on to the other major change, which are daylighting requirements. These are new for the ASHRAE standard and most other standards for that matter. It's been hard up until now to craft a reasonable requirement, but this has finally been done.
There are three separate addenda that encompass this D, AB, and AL. And together they essentially require that you must control electric lighting when there is top and side daylight available that provides good enough capacity to turn the lights on and off. And it will all require that you include skylights as part of your design and construction when again, there is appropriate capability to save some energy. This was developed with some … funding under a subcontract with Hesha Mahone. Who had done similar work previously for the California Title 24 standard. This, of course, was expanded to cover the entire country and other requirements added to it.
So let's look at what those are.
(Slide name: Lighting Control for Toplighting)
The first major one is lighting control for toplighting. And this means whenever you have lighting that comes in through your ceiling. And this is — it comes in two forms. Either skylights or roof monitors. And this includes both. So you'll see that the requirement is for any area under skylights, plus any area under rooftop monitors that exceeds 4,000 square feet as defined. And we'll talk about that here in just a moment. Then you must put in a control for the electric lighting in those areas. And the control must be a multi level control, not just a simple on/off. It either has to be two levels, one between 0 and 35 percent and one between 50 and 70 percent. Or a continuous dimming. That's the basic requirement for toplighting.
So then we have to get into a little bit of detail of how to define where this 4,000 square feet comes from and if it applies to your space.
(Slide name: Daylighting Area Under Skylights (slide 1))
So if we look at that definition for daylight area under skylights, here's the actual words. And they're here for your reference. But I'm gonna skip over them into the drawing, which is much easier to understand.
(Slide name: Daylighting Area Under Skylights (slide 2))
Here's a graphical representation. It shows two skylights. The skylight on the left-hand side of the slide has an obstruction to the right. And the important point is — the formulas are there, but the important point is the obstruction is high enough that it will block the light beyond it. So the extent of the area that you have to daylight extends only to that obstruction. So if by extending to that obstruction you get 4,000 square feet then you're required to put the control in.
On the right-hand skylight there are two other examples. There's an obstruction just on the left, but it's either short enough or close enough to the skylight that light will spill over it into the adjoining space. And therefore, the space you have to use to calculate your 4,000 square feet actually extends beyond the obstruction. And on the right-hand side of that right-hand skylight, the other obstruction you'll notice is just too far away. Excuse me. And it won't block the light that really is effective for top lighting. So the area extends the full length of the standard formula.
And this is really the best way to understand how the definition is applied.
(Slide name: Daylighting Area Under Skylights (slide 3))
There's another top view here which provides the same information. Again, on the left-hand side the obstruction blocks the light so the daylight area ends at the obstruction. On the right-hand side the daylight area goes over that shorter closer obstruction but falls short of the obstruction on the right-hand side.
One other additional item on this top down view, there's a primary side lighted area that overlaps the daylight area. In this case, of course, you only have to have control for one or the other. In this graphic represents that. So even though the language and the formulas can be a little daunting, the graphics here do a pretty good job of explaining when you really have to apply the standard or not.
(Slide name: Daylighting Area Under Rooftop Monitors (slide 1) )
One other item, I mentioned it before, it's the area under skylights or rooftop monitors. For a rooftop monitor we also have to define what that area is. Because you may have one or both in your facility. So again, here are the words. But we're gonna skip right over those into the graphic.
(Slide name: Daylighting Area Under Rooftop Monitors (slide 2))
Here again, we have three different rooftop monitor sections. A saw tooth, typical saw tooth roof. On the left-hand side you have an obstruction that doesn't come in to play. So the area extends as far out as the formula allows it. In the second saw tooth you have an obstruction that again, is too close or too short. So it doesn't block the light. And the formula comes in to play again even beyond that obstruction.
In the third case, on the right hand side you have an obstruction that's high enough or far enough away that it does block the light. And that restricts the area that you have to put the control in. Again, similar type of graphic explanation. Lot easier to see.
(Slide name: Daylighting Area Under Rooftop Monitors (slide 3))
And the top down look of that, again you have a primary side lighted area where you don't have to control both, just one or the other. And this shows you again, the obstruction is too far on the left-hand side. But all of the other space, because the obstructions are either short enough or close enough to the skylight, you would still have to control beyond them.
(Slide name: Lighting Control for Toplighting …Exceptions)
So, let's look at the exceptions. There are always exceptions to everything. In this case there are some spaces or some characteristics that would make it not practical to control the lighting. From generally a cost effective standpoint. The first of those is if there are obstructions that would block the direct beamed sunlight to the skylights or the rooftop monitors. Of course, if it's a small obstruction or only obstructs for part of the day it wouldn't effect. So in this case there are some requirements placed on it that it must be — it must obstruct the light for more than fifteen hundred daytime hours between 8 and 4 PM to make sure it's effectively blocking the lights so the control would not be cost effective.
Also, areas where the — and here's another defined term. Skylight effective aperture of the glazing is less than .6 percent. And I'll describe that briefly here in a moment. And buildings in climate zone eight where the solar capability is quite frankly, less than lower zones. The requirement jumps to 8,000 square feet. So in other words, you only have to put in the control if the day lighted area is found to be 8,000 square feet or greater.
So, the skylight effective aperture….
(Slide name: Skylighting Effective Aperture)
….that I mentioned, again another formula. This value relates to the skylight area and the visual light transmittance capability of the skylight material. So it's essentially the overall amount of visible light you can get through your skylights. And as you can see from the formula, it depends on the area of your skylight, the visual light transmittance value and a factor WF which is the well factor. Most skylights and rooftop monitors have some or a well or an opening into which the skylight is placed. And depending on the characteristics of that space that will effect whether you have to comply with the rule or not.
Again, it seems like a lot of requirements but the formulas are fairly straightforward and only require simple inputs. So calculating whether you need to put in the requirements should be fairly straightforward.
So that covers toplighting.
(Slide name: Lighting Control for Sidelighting)
If we look at sidelighting we have a similar set of requirements. In this case the square footage area is only 1,000 square feet. If your primary side lighted area is larger than that you have to provide the control. And again, it's for general overhead lighting only. And it must be a photo level control similar to the top lighting requirement.
(Slide name: Primary Sidelighted Area (slide 1))
And again, there is a definition. Primary sidelighted area, we have to make sure there's enough area to make the control cost effective. These are the actual words. And once again we're gonna move over to the diagram, much easier to see.
(Slide name: Primary Sidelighted Area (slide 2))
This is a side view. With the window on the left and on the right there is a cubicle partition. And in this case if the partition is high enough, in this case 5 foot or higher, it will block the available daylight beyond it. So you only have to control up to that obstruction.
And look at a top view.
(Slide name: Primary Sidelighted Area (slide 3))
It didn't show it in the previous slide but that cubicle partition only went part of the way across the bank of windows, in this case the two windows. So the primary sidelighted area stops at that partition, but where there is no partition it goes to the full extent of the actual formula. So you have a bit of an odd shaped area, but the idea is any place within that shaded area you must be able to control the overhead lighting, because you will have sufficient daylight to make that cost effective.
And again …
(Slide name: Lighting Control for Sidelighting …Exceptions)
There are exceptions. The biggest one being where there are obstructions to the windows. Based on being twice as high above the windows as their distance away from the windows. This is considered enough to block it so it wouldn't be cost effective. Areas where, again, another defined term, sidelighting effective aperture is less than .1 percent. Or retail spaces. Now, retail spaces, I want to mention this, have an exemption because there are issues with the light levels changing in retail spaces near windows. So they are exempted. But if you have any non-retail spaces with widows this requirement would still apply.
(Slide name: Sidelighting Effective Aperture)
The side lighting effective aperture, another definition, again, this is similar to the top lighting. It's a function of the window area and the visual light transmittance capabilities of the material itself. Again, fairly straightforward formula.
(Slide name: Required Skylight Design & Installation)
So that covers the requirement to control the lighting in the daylight spaces. The last part was the requirement to put in skylights when you have a sufficient size and space. And this requirement is placed in the envelope section, not the lighting section standard because it does have to do with actually structuring the envelope. It does retain the existing maximum 5 percent skylight to roof area limit, even though day lighting might be a good idea for certain spaces, it's generally not a good idea to go over 5 percent skylight to roof area. This creates other issues in terms of heat loss through the building. And would render some of the day lighting not cost effective. So that limit is still in play.
And the requirement is based on a similar daylight area under skylights requirement that we saw before. There is also a requirement that it must be applied in at least 50 percent of the enclosed area. This is in there so in case you have an area such as a conference or ballroom where maybe part of the area you do not want to have daylight because you have to do video presentations, you could exempt that part. But it must cover at least 50 percent of the area. So that's — and that's based on a case by case basis.
There is a — the requirement is based on two different methods. One is the total area of installed skylights must be at least 3 percent of the daylight area with a VLT — that visual light transmittance — of at least 40 percent for the material that the glazing is made of. Or you calculate that skylight effective aperture, which we discussed before. And if it's — it must be at least 1 percent in order to comply. So two ways to comply with that. Fairly straightforward formulas. If you meet those criteria you must put skylights in that open area space.
(Slide name: Required Skylights…Exceptions)
And again, exceptions. If you have enclosed spaces in the colder climate zones, six through eight, where your daylight capability is less, then you don't have to comply with this requirement. But all other zones you do. If you have very low lighting power density in a space, less than .5 watts per square foot, the economics, again are not there. You won't see as much savings and therefore you don't have to put the skylights in those spaces as well.
And a couple of similar exemptions. Again, where direct beamed sunlight is blocked, and this is for the fifteen hundred daytime hours between 8 and 4. Also, from a practical standpoint where the daylight area under rooftop monitors is greater than 50 percent of the enclosed space. What this is saying is that if your space is already going to be designed with rooftop monitors, or in the case of a retrofit already has them, then you're not required to put in the skylights. Because you're already gonna have the capability for daylight in most of the space.
And one other note, when this part of the standard is complied with and you design skylights into the space, then the other parts that we discussed previously of requiring the control in the space will automatically kick in. So you will have a space that has skylights and the electric lighting is controlled appropriately to save energy.
(Slide name: Other Potential Proposals for 90.1 — 2010)
There are a couple of, or a few other potential proposal that I wanted to just mention that may find their way into 2010. These are being worked on now. They're not an official addenda yet. There is a fair chance they will be included in some form in the standard. Just wanted to mention them. One is an interior LPD revision. The lighting power densities for interior spaces. The technical input …?… models have not really been reviewed for quite a few years. And technology continues to change. So you may see a revision based on increased technology in the 2010 version.
We're of course always adding new space and building types. We realize that the table is limited in what it covers. And we want to keep adding space types as they become more important or more prevalent in designs. We're always looking at commissioning. And we believe there will be some commissioning language in the 2010 version to ensure that as much as possible lighting systems and controls are commissioned and working properly before the building is turned over to the owner.
We're also looking at a couple of other items. A ceiling height adjustment factor. The realization is that in spaces where you have extremely high ceilings it may be hard to meet the lighting power density requirement. So it might be appropriate to have an adjustment factor for this.
And additional lighting power allowance for retail spaces. There is some other newer technology, especially throughout …?… that's being looked at that might change those requirements as well. Again, all of these are ongoing items. And you may or may not see them as part of the 2010 version. But we just wanted to give you a heads up.
(Slide name: A Few Words About Interpretations)
Just one more slide. A few words about interpretations. This is an issue that comes up quite often when someone looks at a requirement and doesn't quite understand what it's applying to. Or in a lot of cases you may have a space or building type that just doesn't quite fit the standard as it is written. So sometimes you'll want to get an interpretation of what's actually meant or what would apply. And there are several options.
You can ask ASHRAE for an official interpretation. You can go to their website. Fill out the form for an official interpretation. Yeah. These are considered when they are returned by the full committee, to be the same as the written standard. And they are published by ASHRAE. The downside to this would be the response timeframe because the committee only meets certain times a year, this could be multiple months before you get an official interpretation.
You can also ask ASHRAE at the same website location for an unofficial interpretation. These are considered to be opinions from the development staff. They're not published. They are considered to apply to the intent, but they are not considered a part of the written standard. The upside to that is that typically it can be a matter of days to weeks to get a response to those. But again, they don't have the same official weight as an official interpretation.
You can also email questions to energycodes.gov. The responses you get will be very timely. Usually 24 to 48 hours in most cases. But they are not a formal interpretation. But they are provided by knowledgeable folks on the intent and appropriate application. But again, they are not an official interpretation by any means. But they may provide guidance you might be able to use.
You can also look to your state building department staff or other municipal or county, state staff. They are the ones that are responsible for compliance with the code. And so they should have resources to help you understand what the code requires. In particular if you are in a state that has a state specific code, this is where you would get your primary guidance.
(Slide name: Questions)
And that's it. Hopefully if you have questions you can direct them to the right source. Your input's always valuable to the codes and standards process. So please feel free to give us input when you have it. Thank you.
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