ASHRAE Standard 90.1 2010, Part V– Lighting Provisions


Welcome again. This is Part V of our series on Standard 90.1-2010 of the ASHRAE energy standard. What we’re addressing here is the
Section 9 which covers all of the lighting provisions. Again, we’ll thank our sponsors ARRA,
U.S. DOE, and the Texas State Energy Conservation Office
(SECO). The lighting compliance form initially
looks pretty much like the rest. There is a little change in it. First of all, we do go through the
mandatory provisions and then go on to prescriptive into compliance, but there’s another little change in the
middle of this one. We have another alternative path 9.6. This first alternative path is a building area
method and 9.6 is the space by
space method. Failing to comply in those again,
we can use the Energy Costs Budget, as always. These are the sections in the lighting section of the Standard. We’re going to look at general information initially and then
some of the mandatory provisions and then under that we’re going to be
looking at these two alternative paths. One would think that maybe it’s a
very simple thing to determine how many watts of light you have in the
building by looking at the fixtures, but the Standard certainly requires very
specific methods for determining the wattage. If you have luminaries without
ballasts than the maximum labeled wattage is that of the luminaire. Many times we’ll buy a lighting fixture and it’ll
say maximum 75 watts or something like that, on the
fixture itself. You may screw into that a 60 watt
bulb but the requirement in the ASHRAE Standard
would be that you count that as a 75 watt fixture, so that goes against you on your tally of how many watts
of light you have in the building. If you have luminaries with ballasts
as are most of the fluorescent fixtures, you simply use the wattage of the
lamp ballast combination. If you have track lighting, you use a line-voltage track use
a minimum of 30 watts per foot, or you can use a wattage of the circuit
breaker itself or some other current limiting device on there. For low-voltage track lighting you use the
transformer wattage, and for anything else all miscellaneous
lighting equipment just simply use so the light wattage
that is specified. So the first thing I want to do here is
just go through a little calculation example and this would be to get the total
lighting wattage of a room that contains the following fixtures. We have eight 2’x 4′ fluorescent
fixtures and each one of those has three 4
foot fluorescent T8 lamps, they’re 32 watts each. We have a three lamp electronic
ballast in there, and the ballast wattage is 90
watts. In addition, we have six incandescent
down lights, they’re 60 watts each. The maximum labeled wattage of the fixture is
75 watts. We also have sixteen feet of line-
voltage track lights. They’re specified there are five track
heads and there are 90 watts halogen lamps
for each one. Now here’s a wrong way and a right way to
do it. If you took the 8 fixtures times the
3 lamps times 32 watts, you would get 768 watts. Rather than do that, however, the right
way to do it is to take the 8 fixtures times the 90 ballast
input watts and you arrive at 720 watts. For the down lights, they have 60 watt bulbs in them but the fixture is labeled at 75,
so rather than do 6 times 60, we’re doing 6 times 75 watts arriving at 450 watts
total rather than the 360 watts here. For the track heads on the track lights, we could go with 5 times 90 watts
and get 450 watts which would be the wrong way do it. Instead we use 16 feet of track times 30 watts per foot and we get 480
watts. So the correct answer 1650
watts instead of 1578. The exceptions to all of this are many. Display lighting is accepted lighting that’s integral to
equipment is accepted, anything that is used for food warming
or preparation or plant growth, various things like that. These are all
accepted. Lighting for sports events, casino
gaming areas, furniture displays, parking garages, and transition
areas and so on, a lot of these are exempted from the lighting power density. LPD that’s the term used throughout this section to specify the limits on the lighting power. There are requirements for the shut off. Automatic control options have to
be in place, time scheduling devices that accommodate separate schedules for each floor or space greater than
25,000 square feet, or we need an occupant sensing device
that turns off the lights within thirty minutes of the last
occupant detected in the space. Again, I think we mentioned this earlier, one of the other exceptions
would be some signal from a control or alarm system that indicates the areas is unoccupied that would be
another way to control the light. Exceptions to the shutoff controls are lighting for twenty-four hour operation or where a patient care is rendered or where safety or security of the
occupants could be endangered, things like that. Space lighting control, the Standard requires one
independent readily accessible control that can be seen by the occupants. This must be in each room or space given these conditions. They have to have one control step
between a 30% and a 70% setting of power, that’s in addition to full on and full
off settings. The exceptions to that are corridor,
mechanical rooms, lobbies, or restrooms, spaces with only one luminaire in
them. Also accepted are other spaces that
only have an LPD of 0.6 watts per square foot. The space has to have an
occupant sensor or some kind of timer that turns off the lights within thirty
minutes of vacating the space and that has to be in classrooms, lecture
halls, conference meeting rooms, training rooms
and so on and the Standard lists the entire types of rooms that have to have
that sort of control. The exceptions to that are if you have spaces with multi scene
controls. Shops, laboratory classrooms, any lighting for twenty-four hour
operation and again where shut-off would endanger
the safety or security of the occupants. All other spaces need to have manual or automatic controls. They have to control a
maximum of 2500 square feet in any one area, that’s less than
10,000 square feet or they can control maximum of
10,000 square feet if the space is greater than 10,000 square feet. The automatic
controls can allow occupant override for no more than two hours. There is a requirement for the daylight
controls for side lighting. As I mentioned
earlier, side lighting is basically vertical windows. When the daylight area exceeds
250 square feet the lamps for the general lighting shall be controlled by at least one
multilevel photo control that has the following features and then
they list three here: it has to have a light sensor for the photo cell, calibration adjustments have to be readily accessible, and multilevel photo control shell reduce the electric lighting in
response to the available daylight, and they want one control step
between 50% and 70%, and another control step that’s less 35%, that is of the whole while lighting designed power. And we have some exceptions here: tops of adjacent structures if they’re
twice as high above the windows as their distance from the window, they obviously would make a lot of shade
on the light that would come through the window otherwise so that’s exempt. I put a note here that that’s actually a
65 degree angle as you look out your window, if the building next
door’s top is 65 degrees up than that is enough to exempt you from
day light controls for that. If your effective aperture is less
than 10% that’s also accepted. Retail spaces are exempt. That’s because basically the lighting in
those kind spaces is needed for merchandising. Next, we have day lighting controls
for top lighting a.k.a. skylights. When daylight top lighted area
exceeds 900 square feet that’s the day lighted area, not the
skylight area, but that’s the area that the skylights light than the lamps for general lighting
shall be separately controlled by at least one multi-level photo control that has these features, and that is the light sensor for the
photo control shall be remote from where the calibration adjustments are made. The calibration adjustments shall be readily
accessible. This is much like the other one. And here the multi-level photo control
shall reduce the electric lighting in steps of 50% and 70% of total design power, and one more control step that’s
at less than 35% and that includes the off-position. Exceptions here: where your adjacent structure will
block directly beam sunlight for more than a 1500 hours per year that’s between the hours of
8am and 4pm. If your skylight effective aperture is
less than .6% this means that you have very
little skylight lighting. Buildings that have day lighted space that is less than 1500
square feet in a particular climate zone, that is climate
zone number eight, certainly not applicable in Texas right. Other controls will be required for
these kinds of things. Food warming incubation, plant growth, display cases, task lighting for restaurants, different things like
that, demonstration lighting and so on, these are requiring additional
controls. The exterior of the building, this needs to have controls that turn off the lights basically when
adequate day light is available. That’s pretty much loved the bottom line
for this. Building facade lighting is permitted an
up and so is landscape lighting but it has to be shut off between midnight or business closing whichever is later and 6am our business opening the
next morning similar requirements for
advertising and other outdoor lighting. They have to reduce the power by
30% during those sort of unneeded periods. Exceptions for this would be covered
vehicle entrances, that’s a life safety issue probably
there, and exits from the buildings or parking
lot structures or where requirements are for safety and
security, or eye adaptation. So all those would be exceptions to the
requirement. Exit signs have been reduced to not
exceed five watts per face. So LED lamps are quickly becoming the norm there as I
think almost everyone knows and a a vast majority of incandescent
lights will not meet that LPD requirement at all. And also as you know there’s
a new and federal energy act that will phase out incandescents
by 2014 anyway. So I don’t think incandescent so
be much in the picture in the future in any event. Exterior lighting power, this is based upon what I’d say is
pretty much logic. What it does is permit higher levels of
lighting where there’s more competition from other lights. So ASHRAE committee has divvied this
up into several zones, actually there five, Zone 0-4. Zero is an undeveloped area thats
like a national park or rural area and there you would basically not allow much light
because there’s not much competition. On the other end of the spectrum there
Zone 4 and that’s a high activity commercial
district like a major metropolitan area. Exceptions for this are traffic signal lights, advertising signage, and any equipment or
instrumentation that’s installed by the manufacturer. Those power densities are as follows
this is for again for the building exteriors and it shows zones 1-4. There are no allowances for Zone 0
so it’s not shown here in any kind of a column. So the upper half of this matrix shows what they refer to as tradable surfaces. Tradable surfaces mean if you exceed one of these
a bit you can lower a bit in another surface and then
come in with the proper total and thereby comply with the Standard. So in uncovered parking for example, you’ll see .04 watts a square
foot if you’re in Zone 1, but if you’re in Zone 4 that’s a
metropolitan area, you’d be allowed at least three times that much that’s
.13 watts per square foot. You can see numbers here. Always go up as you progress from left to right, that
is Zone 1 through Zone 4. You’re always allowed more lighting in the
Zone 4. The bottom half of the chart shows
examples of non-tradable surfaces and that would be at ATM
machines you’re allowed 270 watts for each location plus another ninety
watts for each additional ATM machine, guarded entrances are allowed
0.75 watts per square foot, of uncovered areas, any parking at 24 hour
retail entrance you have 800 watts per main entrance. By the way, the reason I show the word
example here is that in the ASHRAE manual this is much more extensive. This list
does go on a lot further than what we’re looking at right here. So there are lots more surfaces to look at so look into those if you ever
encounter in a design problem involving any of these. Here are the exterior lighting
exceptions. If you have specialized signal lights,
directional lights, and so on, advertising light signage, lighting that is integral to equipment, theatrical lighting, sports lights, swimming pool searchlights,
etcetera. So these are all excepted from that. Now I’d like to cover these two alternative paths. This first once called the
building area method. It is the simplest and yet it’s the most insensitive to the details of the building. It’s basically used for the entire
building. So you just see one single number. It says that particular building type is allowed
so many watts per square foot and that’s all there is to it. And the gross lighted area of the
building is measured from outside to outside surfaces. So you’re not measuring the
net area within the building at all. You’re
measuring the entire outdoor area of the building footprint plus the number of
floors in the building. So we’ll have a table that shows the allowance in terms of watts per square foot for
that particular building type. And as I mentioned a minute ago, the limitations on this is that
it’s insensitive to specific space functions, it’s generally a little more
restrictive, it is easier, but it does not apply to all building
types, but if you can select some building type that’s
reasonably equivalent than this still is permitted as an alternative compliance route. I give examples, this is not only
examples, this is the entire list in this case. This is the interior LPD
requirement for these types of buildings and there are 33 or 34
of them here. The building types listed here, starting
with automotive facility going down through workshops, I give the value that was in
existence in 2007 and then what’s in the current Standard 2010, and then show you the difference. The reason I wanted to show this was
just simply to show the amount of new stringency that’s being placed on coming up with these lower lighting
levels. It’s been reduced by a full 16.2%
on an average when you move from 2007 to 2010. The Standard is getting harder to comply
with but presumably that’s ending up in
saving a lot of energy I decided just to do a bar chart to show
this graphically. Some of the building types, this is
all those 33 building types here. Some of the buildings you can see have been reduced a lot. This one shows completely
from this point in 2007 down here to 2010 that’s for dining facilities. Some of these are are almost equal,
like shown here. Anyway, the reduction there’s from an
average of 1.12 watts a square foot to what is now only .9 watts
a square foot, .93 on an average. So the numbers are going down. There are 33 building
types. I thought I’d just do an example here to show you how this would be done.
It’s very simple. You simply look in the list for
these watts per square foot for the different building types, and then you calculate the total lighting power
allowance for your building. If you have an
office building that is six floors, these are the outside dimensions 200 by 350. You note on the power allowance
chart, this is only allowed .9 watts a square foot for an office
building. The way you do that is, you just simply
multiply the area, length by width, that’s the area per floor, multiplied by six floors you get that, multiply that by .9 watts
a square foot and you get that many watts. So that’s your total lighting
power allowance, 378 kilowatts. Had you use the 2007 Standard, you would have been allowed
420,000 watts. So this basically saves 42,000 watts of energy or power I should say in the building,
42 KW. The space by space method, this is the alternative path number two. You’re basically now going to identify
different building types in your project, and you have to look at all the details
within the building itself and come up with those spaces. For example, you’ll have corridors, you’ll have restrooms, you’ll have conference rooms, you’ll have offices, and many other types of rooms. I think in the ASHRAE Standard if you look at this there are about 95 different space types within
the chart within the table. And when you do that you sum up all
the allowances and then you simplysee if that
complies with with the Standard. So again, here are some of the spaces. For example, offices enclosed have a
little different number than offices than open offices, and a conference room a little
higher, training rooms slightly higher, the lowest one on the list would
be a dining facility here .65, corridors have .66, restaurants
have .98, storage rooms being the lowest of all
would be .63. So these are just some examples of
those spaces. There are allowances given for some
additional interior lighting. If you have a need for decorative
lighting, they’re allowing another watt per square foot, just in that space that used. If you’re lighting equipment installed in retail spaces to highlight merchandise the numbers are as follows: if you
have sales areas for general consumer goods it’s .6 watts a square
foot, if you have vehicles that’s another
.6 watts a square foot, furniture, clothing, and cosmetics,
artwork, and so on 1.4 watts a square foot, and finally the largest increment of all
the fine jewelry, crystal, and china 2.5 watts a square foot. So that’s quite an increment over what
you would be allowed otherwise in that space. What I thought I’d do is also go
through an example with the space by space method. We’re going to calculate the total
lighting power allowance using the space by space method using this particular
retail building, five thousand square feet of
sales area, it happens to have a thousand square
feet of jewelry counters, also a thousand square feet of
storage, has three enclosed offices 200
square feet each, it has a conference room, two restrooms, and has corridors six feet wide by twenty
five feet long. So basically, you would go to the list of allowances and look at the sales area that would come in at 1.68 watts a square
foot. Look at the additional lighting power
allowance for the jewelry case that would be 2.5 watts a square foot, the active storage area was this .63, and then we have numbers here for the
enclosed and office and conference room, restrooms and corridors. So we multiply these all out: 1.68 times a square area of the building. Active storage area same procedure. In each case we just simply multiply
that allowance by the area of that particular space and come up with
this many watts, add those up and then at the end, add on that
additional power allowance. In the jewelry area, we were allowed 2.5 watts a square
foot times a thousand square feet so we have 2500 more
watts. This total internal power allowance then is 13,081 watts and just as a reference point, once
again, I went back to Standard 2007 and found this
would have allowed 15,025 watts. So again we saved 1,944 watts by going to the new standard versus the old standard. On lighting alterations, we’re hitting this on each of the
sections. There is a replacement of less than ten percent of the luminaries in a space that’s accepted. It does not have to meet
the the standard requirement for the
lighting power density. But, there’s always a but here, it must not increase the install
lighting power density. Note, replacement of luminaires and
components only, the lamp and ballasts this also constitutes an alteration for
compliance purposes. If you’re doing routine maintenance or
repairs though, it’s exempt. This concludes our five part
presentation on the various sections of the ASHRAE Standard
90.1- 2010. I hope you appreciated and enjoyed the presentations. It should be known that ASHRAE
has already undertaken the writing of Standard 90.1- 2013 and of course that will appear in a couple
of years. Many of the addenda from 2010
have already been issued and they will become part of the Standard 2013. I’m hoping any application of either Standard
2010 or 2013 will involve a lot of energy savings within the state of
Texas and throughout the country, and hopefully this will be of use to
many designers both mechanical, electrical, plumbing, architectural. Thank you very much for your attention.

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