Exterior Lighting Code Issues
October 8, 2007
NC ENERGY CONSERVATION CODE CHAPTER 805 EXTERIOR LIGHTING CHANGE UPDATE
On January 1, 2007, the NC Building Code enacted some exterior lighting changes. The changes effect both the lighting levels as well as the controls for light fixtures. As far as controls for exterior lighting, you are now required to have either a photocell or an automatic controller with a battery back-up. Both of these are good design practice and have been utilized for a long time, but they have never been a code requirement. Since most interior spaces are now required to have a lighting control system as well, it usually will not cost any additional construction money to use the same system to control the exterior lighting.
There are several options when it comes to control systems for lighting: programmable panels, low voltage lighting systems, lighting contactors and stand alone controllers, etc. Note that the code requires a battery back up for all such controllers, so it is still being debated in our office as to whether programmable panels will qualify (they have no battery, but retain their memory during a power outage).
Another change which occurred is the abolishment of incandescent lights for exterior lighting. The only exception to this is low voltage landscape lighting, and lighting for security purposes (obviously this is a debatable item: but officer, I needed those 14 floodlights aimed at my building façade to keep thieves from breaking the windows!). The code states that all exterior lamps must have a source efficiency of 45 lumens/watt. This cannot be achieved by any incandescent source, so therefore incandescent lamps are not permitted.
i. For exterior lighting, must have an automatic timer with a programma
2. How does these changes tie into LEED
a. Dark Skies - Must meet IES RP 33 maximum lighting levels. All fixtures over 1000 lumens must be shielded, all fixtures over 3500 lumens must have full cutoff. Maximum candela ratings must be within property lines. This implies that a photometric must be done to prove result
Interior Lighting Level Issues
October 8, 2007
NC ENERGY CONSERVATION CODE CHAPTER 805 INTERIOR LIGHTING LEVELS CHANGE UPDATE
On January 1, 2007, the NC Building Code enacted some rather startling lighting changes. The changes effect both the lighting levels as well as the controls for light fixtures. The code changes effect every type of building with the exception of dwelling units (apartments, condos, residences, and the guest rooms in a hotel). The changes that affect lighting levels can be summarized as follows:
The "Power Levels" for maximum Watts per Square Foot for all types of buildings have drastically been reduced. The most typical is for office spaces. The maximum level went from 1.5W/SF down to 1.0W/SF. This is a reduction of 33%. To illustrate this, let's take a typical office - 10' X 14' (okay, not typical, but it works well for illustration purposes because the larger size requires two light fixtures). Under the old code, you could install two 2X4 acrylics with three T8 lamps, or two 2X4 parabolics with three T8 lamps, or one 8 ft indirect fluorescent with a cross section of three T8 lamps. All three of these options gave you more than adequate footcandle levels (43, 49, and 32, respectively), but all three options use 1.27W/SF. This was way under the 1.5W/SF requirement, but it does not come anywhere close to the new 1.0W/SF requirement. Basically, it comes down to the fact that you can no longer indiscriminately use acrylic and parabolic fixtures with T8 lamps and hope to meet the energy code.
The option available to us is the newer T5 technology.
As a quick summary, here are a few of the maximum power levels now required under the North Carolina Building Code:
- Retail 1.6W/SF
- Educational 1.2W/SF
- Restaurants 1.6W/SF
- Power Levels
- New Buildings: 10.5% to 42% less than ASHRAE standards (1 to 10 points) - lighting is approximately 25% of load, so reductions below levels above help greatly
- Existing Buildings: 3.5% to 35% less than ASHRAE standards (1 to 10 points)
- We are available to lay out lights.
Interior Lighting Control Code Issues
October 8, 2007
NC ENERGY CONSERVATION CODE CHAPTER 805 INTERIOR LIGHTING CONTROLS CHANGE UPDATE
On January 1, 2007, the NC Building Code enacted some rather startling lighting changes. The changes effect both the lighting levels as well as the controls for light fixtures. The code changes effect every type of building with the exception of dwelling units (apartments, condos, residences, and the guest rooms in a hotel). The changes that affect lighting controls (switching) can be summarized as follows:
All rooms will require two lighting levels (i.e. two switches), unless there is only one light fixture in the room. This has been a standard design practice for a long time, but now it is a requirement for all rooms. In addition to this, the real item you need to watch out for is that if a building area (the size of the area being renovated) exceeds 5,000 square feet, then an automatic control system has to be provided to shut off all lighting on a scheduled basis. Along with this control system a user override switch has to be provided for each area of lighting, with the override not lasting more than 2 hours. To simplify this, if you have a 6,000 square foot building (or an equivalent size upfit in a much larger building), then a control system has to be in place to turn on the lights at, say 7:00am and turn them off at 7:00pm on weekdays. If an employee comes back at 9:00pm, then he or she needs to have a switch going into the open office area which will turn on the lights for up to 2 hours. They will then walk to their own individual office and turn on the light switch in their office. After 2 hours, the lights go out and the individual has to get up and go turn them on again.
The exception to this requirement is the addition of motion, or occupancy sensors. If occupancy sensors are installed in an individual room, then the multiple lighting level requirement is not needed (although we recommend it as a good design practive). If occupancy sensors are located in all areas of the building, then the lighting control system is not required. There are exceptions to these requirements, but they are mostly common sense. You do not need controls to meet these requirements in common corridors, stairways, toilets, security areas, patient care areas, or storage type rooms.
One additional thing that the design community needs to be aware of: there are more items on a ceiling than ever before: motion sensors, daylight sensors, fire alarm audio/visual devices, lights, diffusers, smoke detectors, etc. Care must be taken to coordinate all these devices between the different engineering disciplines and the architect. There are more ways than ever to make a design mistake!
New Schools - Can They Be Anything but Green?
October 5, 2007
Sustainable buildings are great for everyone, with the possible exception of the short term investor.A well designed building with sustainability as one of the top priorities will result in a less expensive building to own and operate over the life of the building, but there is usually additional upfront construction costs.And, if you are going to sell your building within 3 years of building it, you probably aren’t thrilled about additional upfront cost.The best candidate, therefore, for a sustainable, or “green” building is a facility with the same owner over a long period of time.One of the best owners that fits this profile is government.Schools fall under this umbrella.Most school buildings remain schools for many, many years.A well designed and well built sustainable school will use less infrastructure and require less maintenance, and thus need less money to operate for a long time.This is not only good for the taxpayer, but the studies prove again and again that a well designed school offers a better learning environment: a win/win scenario.
All this being said, would any school system want to build a new school that is not “Green”?Of course not.But the real key here is education.Educate the taxpayer.Educate the teachers and administrators.Educate the school boards.And educate the contractor.A contractor must realize that cheaper is not always better.Sometimes more expensive is actually cheaper!We as a society have to begin looking at the Total Cost of Ownership.We used to build buildings which would last hundreds of years, but that no longer seems to be the case.The Total Cost of Ownership can be very high for a facility which had inexpensive construction cost.
There are systems in a building which cost more to install, but which will pay for themselves with energy savings in two years or less.Two years!Lighting is a great example.I can pay more upfront during construction, install a more expensive, yet more efficient light fixture, and the payback for the fixture is two years.That is over a 40% guaranteed return on your investment!If I told everyone reading this that I could guarantee a 40% return on their money in the stock market each year for the next two years, you would be borrowing money to give to me to invest!Who wouldn’t?Yet, we can be so shortsighted when we build a building that we forget it costs money to maintain and operate a building.Guaranteed 40% return!Warren Buffet would be proud!
One of my favorite comments was from a school facility manager for a large private school.After trying to get her to see the common sense of spending a little more money up front, but saving a lot of money forever, she first asked me what I got out of it (nothing but heartburn by trying to educate her – she confused salesman with design engineer) and then she finally said that the utility money came out of a different budget than her construction budget and she really didn’t care if the school saved money out of the utility budget!As I said, it is an education process.
LEED® has been a buzzword for the past several years.The best thing about LEED® and it’s impact on society is that more and more people are becoming aware that our planet does not have limitless resources.Yet we can live, work, and be educated in wonderful buildings which have a minimal impact on the environment, but we have to make the conscious effort to do so.It is a major paradigm shift.Education is the key.What better way to educate the next generation in the wise use of our planet’s resources than by educating them in a facility that does just that!We can design and build great educational facilities that cost less to own and operate than traditional schools, and we can show our children how they do not have to suffer and sacrifice to keep living in the standard of living that our country now knows.In fact, the buildings can be better than they have been and actually improve our quality of life, while at the same time costing less to own and operate as well has reducing their impact on the environment.Talk about Win/Win!As I stated earlier, when one takes the time to thoroughly analyze the school building options, Green is the only way to go!
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