Window Covering Design

The selection of blinds, window coverings, or the lack thereof is likely the most crucial choice a designer will make when seeking to ensure visual comfort while maintaining daylight performance over time. We have all seen buildings where blinds are down continuously. Typically, this is associated with visual discomfort (glare). The most common source of glare issues in daylighting is a line of sight to the disk of the sun. Selecting a window covering that is opaque enough to block the sun, such as fabric window shades with 3% or less openness or horizontal blinds, can control this phenomena.

Manually operated blind systems can be very effective if properly used. More specifically, a 2" horizontal blind with a white finish can function as a series of mini light shelves casting indirect light into the space when desired. However, they rely on and require constant user attention to maintain complete glare control while achieving maximum daylight performance. For this reason, blinds or shades are often permanently deployed at the ¡°worst case scenario¡± position to maintain visual comfort throughout the day and year. This typically results in poor daylight performance and the elimination of views to the exterior.

Automated glare control has the distinct advantage of being deployed only when needed and retracting without user intervention when direct sunlight is no longer present to allow for unimpeded diffuse daylight. In most cases, this will deliver longer periods of effective daylight contribution, increased electric lighting power savings, and longer durations of unobstructed views to the exterior. Automation of glare control may provide the most persistent daylight performance where low angle direct sun is present during extended periods of occupancy.

< Direct sunlight can cause visual discomfort. Shutting the blinds here would eliminate the benefit of the daylight.




Example of split window covering strategy to preserve views or block sun where needed, allowing for indirect light into space. >

 

 

 

 

 

 

Shading and Exposure Tips:

• North - Shading may only be needed in early morning or late afternoon.
• South - Good access to strong illumination but varies throughout the year. Shading is easier than East/West.
• East/West - Shading is difficult but critical for comfort.

Lighting Metrics: Quantity, Quality, Efficiency

Because some 85% of human impressions are visual, proper quantity and quality of light are essential to optimum performance. The mission of lighting management is to provide the optimum quantity and quality of light to its users at the lowest operating cost.

Lighting metrics are used to understand and predict how a lighting system will operate. They deal with quantity of light (light output and light levels), quality of light (brightness and color), and fixture efficiency (electrical efficiency and how much light leaves the fixture).

QUANTITY OF LIGHT

Luminous Flux (Light Output). This is the quantity of light that leaves the lamp, measured in lumens (lm). Lamps are rated in both initial and mean lumens.

Initial lumens indicate how much light is produced once the lamp has stabilized; for fluorescent and high-intensity discharge (HID) lamps, this is typically 100 hours.

Mean lumens indicate the average light output over the lamp's rated life, which reflects the gradual deterioration of performance due to the rigors of continued operation; for fluorescent lamps, this is usually determined at 40% of rated life.

A number of factors affect a lamp's light output over time, including lamp lumen depreciation, the lamp's interaction with the ballast, supply voltage variations, dirt or dust on the lamp, and the ambient temperature in the fixture.

To avoid confusion, note that "lumen output" is a term also used to describe a fixture's light output, not just a lamp's. Even more factors can affect light output in this case, including the distribution characteristics of the fixture, fixture surface depreciation, and dirt and dust buildup.

Illuminance (Light Level). This is the amount of light measured on the workplane in the lighted space. The workplane an imaginary horizontal, tilted or vertical line where the most important tasks in the space are performed. Measured in footcandles (fc) (or lux in metric), light levels are either calculated or, in existing spaces, measured with a light meter. A footcandle is actually one lumen of light density per square foot; one lux is one lumen per square meter. Like lumens, footcandles can be produced as either initial or maintained quantities.

Initial footcandles indicates a light level after new lamps are installed.

Maintained footcandles indicates a light level after light loss factors are considered over a period of time. Light loss factors include those affecting light output (see above) and also room surface reflectances, room size/proportions, dirt and dust buildup. While light output may describe either the output of a light source or fixture, maintained footcandles always takes into account the efficiency of the fixture in transmitting light to the workplane.

The human eye is a sophisticated piece of machinery; it is able to adjust to a wide range of light levels, including about 10,000 footcandles on a sunny day to about 0.01 footcandles under full moonlight. However, optimum ranges of light levels have been established for various tasks so that those tasks are performed most efficiently (reading a magazine, for example, would be difficult under moonlight, while 10,000 footcandles would be excessive).

For more information, see Lighting Design Basics and Light Loss Factors.

QUALITY OF LIGHT

Luminance (Photometric Brightness). The light that we actually see, brightness can be measured as the light leaving a lamp, or the light reflecting from an object's surface. If not controlled, brightness can produce levels of glare that either impair or prevent a desired task being performed. Glare can be described as direct or reflected glare, which can then result in discomfort or disability.

Direct glare comes straight from the light source.

Reflected glare shows up on the task itself, such as a computer screen.

Discomfort glare does not prevent seeing makes it uncomfortable.

Disability glare prevents vision. A popular example is holding a glossy magazine at a certain angle; a veiling reflection results, impairing our reading of the page.

Color. The color quality of a lamp is revealed as its color temperature rating and Color Rendering Index (CRI) rating. For a detailed description of these metrics, see Color Metrics

FIXTURE EFFICIENCY

There are two ways to look at a light fixture's (luminaire's) efficiency; one indicates how well the lighting system transforms electrical input into useful light output, and the other indicates how well the fixture itself transmits light from the lamp(s) to the workplane.

Electrical Efficiency. Lighting systems require electrical input to work. This input is measured in watts (W), a measure of required electric power. A lighting system's rated input wattage, therefore, is the amount of power required for it to work at any given instant of time.

Lamp manufacturers publish nominal wattage ratings for their lamps; when fluorescent and HID lamps are operated as a system with a ballast, however, a new rated wattage will result, published by the ballast manufacturer. Ballast manufacturers publish up to three input wattage ratings. The ANSI number is the result of a standardized ANSI test of that given ballast manufacturer's ballast operating a given compatible lamp type (often called the "bench test" because the lamps and ballasts are operated bare on a bench). The next one or two are the manufacturer's ratings for tests in actual open and/or enclosed fixtures.

While the manufacturer's ratings can be considered more realistic (because the testing takes place closer to actual field conditions), the ANSI number should be used when comparing different ballasts because it reflects the results of a common, standardized test procedure.

Therefore, one way to compare the electrical efficiency of lamp-ballast systems is to determine a common light output level, then compare the input wattage for various systems.

A more popular way of achieving a comparison of the relative efficiencies of lighting systems is to use efficacy, expressed in lumens per watt (LPW or lm/W). To determine a system's efficacy, divide its lumen output by its rated input wattage.

When lighting professionals apply the results of efficiency to actual system operation (usually to determine the operating cost savings of a retrofit, they need to determine the amount of energy the lighting system consumes, not just its input wattage. To calculate the energy use of a lighting system, multiply input wattage (W) x time (hours of operation during a year).

Example for Lighting System:

Input Wattage	100W
Lumen Output	10,000 lm
Efficacy	100 LPW	10,000 lm ÷ 100W
Hours of Operation	3,120 h	5 days/week x 12 hours/day x 52 weeks/year
Energy Use	312,000 Wh	100W x 3,120 hrs/year
Energy Use	312kWh	312,000 watt-hours (Wh) ÷ 1,000 = 312 kilowatt-hours (kWh)
Utility Charge/kWh	$0.075
Energy Cost/Year	$23.40	312kWh x $0.075/kWh

Locating Lights, Transforwers,Materials And Dccessories Required

Show Typical Switched Wiring Circuits For A Lighting Installation

Whichever type of fitting you intend to use, draw a scale floor plan of the room, clearly mark where items are and where you wish relevant lights to be. When you have completed your plan, mark the ceiling / wall with the centre position of the fitting, making sure you mark the position of cutouts, before cutting or drilling, ensuring there are no obstructions, cable or pipes behind. Fitting lights on the ground floor may require you to have access to the floor above so ensure floorboards can be accessed.

If installing recessed down lights ensure there is enough clearance in the ceiling void, you will find minimum distances stated in the supplied instructions. Ensure the integrity of any fire barrier is maintained especially where there is a dwelling above the site of the fitting(s).

FIG. 6 show typical switched wiring circuits for a lighting installation.

alternatively you can use the existing 230V supply from the loop-in terminals of a ceiling rose supplying existing 230V lighting. Always read the light fittings instructions before attempting any work and if in doubt, consult a qualified electrician. Lighting circuits are usually controlled from a 5amp fuse at the main board and most new installations require this to be protected by an RCD operating at 30mA. In a two-storey house there are usually two lighting circuits, one for each floor.

Using the above information, you should now be able to calculate the amount of cable and where any switches should go. NOTE: always allow extra cable as it is easier to trim back than to add. This will also give you some flexibility if you have to adjust the positioning of a fitting.

Fitting Lights And Electrical Connections

Installing a light fitting is straightforward but at this stage don't fit lamps into their housings. Once all the cabling is in place you can then fix any brackets using suitable fixings ( taking care not to drill or screw through any cables ). Ensure all terminations are secure and comply with the Wiring Regulations that your light fitting complies with BS EN 60598, the British Standard for light fittings.

NOTE: Fittings classed as Double Insulated ( Class II ) or SELV ( Class III ) do not require an earth and fitting instructions should be followed. TIP: When using multiple lamp fittings, or when low voltage fittings are supplied via a transformer, a bulb / lamp reaches the end of its life; it is good practice, to replace as soon as possible. Failure to do so may cause 'overvolting' of the other bulbs / lamps and could reduce their lifespan by up to 50%. Always ensure that the bulbs / lamps are sufficiently cool before replacing.

Detection Of Motion

with the European Standard for luminaries (BS EN 60598) and carry a CE mark. Depending on where the light fitting is to be sited will determine the degree of protection the product will need against ingress of moisture. This is known as an IP rating i.e. IP44. Simply put, the first number of an IP rating (0-6) is the degree of protection against debris, dust and even 'little fingers' getting in. The second number (0-8) is its resistance to moisture. IP68 is the highest degree of protection offered against dust, solid objects & moisture.

Outdoor Light Of Materials And Dccessories Required

Outdoor light fittings will require some maintenance, so choose one made from a material suitable for the local environmental conditions i.e. if you live near to the sea, select a plastic or marine grade stainless steel product that will require minimal cleaning and is not prone to corrosion. Always check manufacturer's zcare instructions.

Having decided, what, where, how you wish to light and how many different moods you want to create, make a plan of your garden, identifying lengths, quantities of materials and accessories required. These may include switches, P.I.R. sensors, conduit, armoured cable (above 50V), an RCD, fixings, weatherproof junctions boxes, cable joints, glands etc.

NOTE: Outdoor Fittings operating under 50V can use conduit to protect the cable. Fittings operating above 50V must use armoured cable and be protected by a RCD, with a residual operating current not exceeding 30mA.

Once you have selected your fittings and accessories, using your plan, physically mark out the areas in your garden where the lighting is to be sited and the cable is to be run. Prepare the ground for the cables by digging channels - for cables operating at above 50V or where the ground is likely to be disturbed, the trench must be at least 500mm deep.

The cable route should be marked with yellow and black tape. It should be just 150mm below the surface, above buried cable; this is to warn persons excavating the ground in the future that a cable is present. It is also a good idea to keep a garden plan showing all cable routes and depths for future reference.

NOTE: When laying cable, always leave an extra length for any last minute adjustments; it is easier to reduce the length than it is to add. Don't back fill until you have completed, tested and are happy with the positioning of the system.

When installing recessed ground lighting in a drive or pathway, you should provide suitable drainage; bedding the base of the fitting onto gravel can easily do this.

Once all the cabling is in place and you are happy with the location of the fittings, make sure the securing method is suitable for the size and weight of the fitting, the surface to which it is to be fixed and its exposure to the elements. When all this is done, connect the supply cable, re-check all connections and fit bulbs / lights. Only when you are happy with the installation and it has been checked, can an 'Authorised Competent Person' connect the mains power supply. Switch on and test. Back fill any trenches and make good.

Even the best garden lighting designers don't always get it right first time. If this happens to you, it may just be a case of a little adjustment or even some trial and error but it's worth persevering. You can easily add a new circuit or more lights if necessary.

NOTE: Always keep your garden lighting plans for future reference.

All outdoor electrical work must conform to BS 7671 the current IEE wiring regulations, and Part P of Building Regulations, you are advised to check with your local authorities Building Control Department, or an Authorised Competent Person, before starting. If in any doubt about electrical work, contact a qualified person.

LED Tube Light Installation Made Simple

Installing LED tube lights is a great way to save money on electricity and get potentially hazardous fluorescent lights out of your home or office. However, most LED tube lights on the market today can not just be directly installed in an existing fluorescent fixture. You will have to make some simple modifications to the fixture to properly install the bulbs. The good news is that installing an LED tube light in an existing fluorescent fixture is relatively simple. In addition, you should be able to buy fixtures especially designed for LED tube lights in the near future, and they should actually be cheaper than the equivalent fluorescent fixtures. This article will provide a brief overview explaining what you need to know in order to install the new energy-saving fluorescent tube lights in an existing fluorescent lighting fixture.

Fluorescent fixtures are designed to support a specific types and size of fluorescent tube. A fluorescent tube is incorporated into a fluorescent lighting system which consists of two or three main components:
(1) the fluorescent lamp (fluorescent bulb or tube),
(2) the ballast, and
(3) the starter system.
In addition, the system for a tube lamp includes a lamp holder and a switch. Depending on the particular fluorescent lighting system, the starter may be a replaceable component, a starter may not be required, or the starter function may be integrated into the ballast. The starting function may also rely on the physical design of the fixture. To retrofit a fluorescent light fixture to support an LED tube light, the ballast (and the starter if a separate one is present) must be disconnected.


Make sure that the LED replacement tube lights are the correct size for the fixture. Also, always remember that when servicing a fluorescent fixture or lamp for any reason, electrical power to the entire fixture should be disconnected. This is not always practical in situations where a large number of fixtures are controlled from the same power control (such as in open office areas). In these cases, insulating gloves and a nonmetallic ladder should be used if the fixtures must be serviced when power is present.

You will need a few simple tools, including a wire cutter and wire stripper (often incorporated into the same tool), a pair of pliers, a screwdriver, and a few wire nuts for reconnecting the wires once you have removed the ballast.

Once the old bulbs are removed from the lamp holders and the electricity to the fixture is turned off, you will probably have to remove the reflector that is located behind the bulbs and provides a housing for the wiring and ballast that lie behind it. Typically, it is fairly simple to remove the reflector or cover, but if it is not clear how to do this, you should consult the documentation from the fixture manufacturer.

If the fixture has an electronic ballast, you only need to remove that and then wire the power directly to the lamp holders, completing one circuit for each bulb. This is fairly simple, and typically you can use the existing wire in the fixture and then just add some wire nuts. If you have an older fixture with a magnetic ballast and starter, you will have to remove or open the starter and remove or short the magnetic ballast.

Depending on how much wire you have to work with, it is a good idea to leave long enough wires leading out of the ballast to be able to reconnect the ballast with wire nuts, if you should ever want to convert the fixture back to use for fluorescent bulbs or want to use the ballast somewhere else. Typically, the ballast will have two screws or bolts holding it in place in the fixture, and these can be removed using a screwdriver or pair of pliers, as appropriate. The ballast should be disposed of in accordance with local regulations as should the old fluorescent bulbs. Because the fluorescent bulbs contain a small amount of highly-toxic mercury, they should be treated as hazardous waste and disposed of accordingly.

Once the ballast (and starter, if one was present) have been removed and the wires reconnected to complete a circuit for each bulb, replace the reflector or cover over the wiring and the area where the ballast was located, and the LED tube lights can be inserted in the end sockets. Unlike fluorescent bulbs which do not have a top or bottom, an LED tube light will have an obvious top and bottom, with metallic heatsink located on the backside of the tube and the LEDs visible under a lens on the side that will be aimed towards the area to be illuminated. Place the cover back on the fixture (if there was one) and turn on the electricity. Turn on the switch and if you have done everything properly, you should have as good or better lighting using approximately half the electricity and lasting as long as 50,000 hours or more.

How to install led light tube t8 t10 retrofit tubes

Step 1. Unpack the product:

• Unpack and carefully examine the product from top to bottom.
• Report any damage and save all packing materials, if any part was damaged during transport.
• Do not attempt to use this product, if it is damaged.

Step 2. Planning the installation:

• This device installation requires planning to ensure
• successful installation with minimal complications and down time.

Step 3. User responsibilities:

• It is the responsibility of the contractor, installer, purchaser,
• owner, and user to install, maintain, and operate the device in such a manner as to comply with
• all state and local laws, ordinances, and regulations.

Step 4. Product installation steps:

• Disconnect power to fixture at source. DO NOT SIMPLY SWITCH OFF FIXTURE
• Remove existing fluorescent tubes and safely set aside.
• Disconnect (cut) wires to ballast leaving enough wire to be tied off with wire nuts.
• Tie-off remaining wires attached to ballast with wire nuts.
• See wiring diagram shown on reverse for your type lamp fixture (i.e., 1-bulb, 2-bulb, 4-bulb and etc.) and re-wire fixture.
• Install Aladdin LED Retrofit Tube(s) into fixture.
• Affix included warning labels to fixtures near lamp connection/sockets of fixture so they are visible to bulb installers.
• Re-connect power supply and turn on switch. Tube will light.

Risk of fire or electric shock. Install the LEDaladdin T8 T10 retrofit LED tube(s) only in luminaires that have the construction features and dimensions shown in the photographs and/or drawings shown on reverse of this sheet.

Caution:

• Please read and follow these instructions before installation.
• Install the tube by qualified electrician and technican.
• Consult the competent electrician if you have any uncertainty about the installation or the use of the product.
• Do not impact the tube and all its components by any external weight or mechanical force.
• Do not use harp tools near or on the surace of the tube.
• Hands must be dry during installation.
• Switch off the power before installation.
• Make sure the base is mounted on a stable. even and secure surface.
• Beware of electic shock when replacing tube.
• Use or store the tubes in dry places. if the tube are used for outdoor application. waterproof holders and covers are needed.
• Replace the tube immediately if you find any leakage or damage on the tube.
• Stop use and replace if the product becomes dim,out of order or begins to blink.
• Of failure occurs do not attempt to repair product.
• This is not a dimmable product . do not use with dimmers.

Warning

• NOTE: This user guide is intended to be used as a reference only. Installation should be done by a fully qualified
• electrician or technician. This document should never be considered as a substitute for any provision of a regulation or
• state and/or local code. Please read the entire user guide to fully understand and safely use this product.