GB2537666A

GB2537666A - Positioning of lighting units or luminaires

Info

Publication number: GB2537666A
Application number: GB1506911.5A
Authority: GB
Inventors: Skevington Thomas; Warner Peter
Original assignee: P4 Ltd
Current assignee: P4 Ltd
Priority date: 2015-04-23
Filing date: 2015-04-23
Publication date: 2016-10-26
Also published as: GB201506911D0

Abstract

The method comprises the steps of: selecting from a database of different lighting units or luminaires plurality of lighting units or luminaires 20-34 for use in the installation, the database comprising a footprint 36 for each of the different lighting units or luminaires, the footprint comprising a particular isolux contour at floor level 38, 40 for each lighting unit or luminaire at one or more predetermined mounting heights; importing the relevant footprint for each of the selected plurality of lighting units or luminaires into a computer-generated plan of the building or location in which the lighting installation is to be installed; and adjusting the number and/or positions of the plurality of lighting units or luminaires such that the footprints thereof indicate that a desired minimum level of illuminance is achieved in one or more selected portions of the plan.

Description

Title: Positioning of Lighting Units or Luminaires

Field of the Invention

This invention relates to a method of positioning lights, especially emergency lights, and to an emergency lighting system having emergency lights positioned according to the method.

Background of the Invention

It is a legal requirement for commercial and industrial premises to be provided with io emergency lighting which operates when the normal lighting, or parts thereof, fail (e.g. due to a generalised power cut, fire or a localised circuit failure). The functions of the emergency lighting include: indicating clearly the escape routes from the premises; providing illumination along the escape routes to allow safe movement of occupants towards the emergency exists from the premises; and ensuring that fire alarms and fire fighting equipment can be readily located.

The relevant standard relating to emergency lighting is BS5266 (and, more especially, part 7 thereof) and the equivalent European standard EN1838 (latest revision 2013). This standard requires, inter anti, a minimum level of illuminance. This should be at least 1 Lux along the centre line of a corridor, or at least 0.5 Lux in open areas.

Accordingly, it is necessary to position emergency lights so as to achieve the desired minimum level of illuminance to comply with BS5266/EN1838. Currently, there are two methods which are commonly employed to assist in determining the optimum placement of emergency lights, so as to achieve the necessary minimum level of illuminance, using the fewest number of emergency lights.

One such conventional technique involves the use of "spacing tables". These are tables produced by the manufacturers of emergency lighting units or luminaires which show the maximum spacing between luminaires compatible with achieving a specified minimum illuminance (typically I Lux) at floor level in an installation. The spacing will depend on several factors including: the mounting height (i.e. the height of the luminaire above the floor, most luminaires being ceiling-mounted), and the characteristics of the luminaire (e.g. number and nature of light sources in the luminaire; directionality and distribution of light output and so on). Whilst such spacing tables do convey the necessary information, it is not in a form which is readily manipulated or exploited. For example, it requires a person planning an emergency lighting installation to transpose luminaire positions onto a drawing or plan, based on the spacing information contained in the table, and this can be a relatively time-consuming process.

A second conventional technique involves the use of commercially available io photometric software. Two of the most widely-used packages are ReLux') and DIALux'u. These are free-to-use programs, but luminaire manufacturers and/or distributors pay to register their products. Each package contains a database of different emergency lighting luminaires and their associated light distribution intensity characteristics. Typically, users input a CAD (computer-aided design) file, is (e.g. such at produced by AutoCADR), showing a plan of the premises in which the emergency lighting is to be installed, and select one or more particular luminaires from the database in the ReLuxi' or DIALux® package. The program output provides a grid of floor-level light intensities superimposed on the floor plan (i.e in a grid of numbers), which shows whether the necessary minimum illuminance is achieved using the selected luminaires. However, even using this technique can take quite a long time, and some degree of trial-and-error may be involved. Also, the output from the software is not entirely intuitive or easy to understand without some prior knowledge or experience.

Accordingly there is a need for a simple, yet fast, method for determining optimum placement of lights or luminaires, and preferably a method which provides an immediately intuitive result or output.

The present invention aims, in preferred embodiments, to provide a method for selecting the position of lights which is an improvement, in at least some aspects, over one or both of the existing conventional methods described above.

Summary of the Invention

In a first aspect, the invention provides a method of selecting the number and/or positions for a plurality of lighting units or luminaires in a lighting installation, the method comprising the steps of (a) selecting, from a database of different lighting units or luminaires, a selected plurality of lighting units or luminaires for use in the installation, the database comprising a footprint for each of the different lighting units or luminaires, the footprint comprising a particular isolux contour at floor level for each lighting unit or luminaire at one or more predetermined mounting heights; lo (b) importing the relevant footprint for each of the selected plurality of lighting units or luminaires into a computer-generated plan of the building or location in which the lighting installation is to be installed; and (c) adjusting the number and/or positions of the plurality of lighting units or luminaires such that the footprints thereof indicate that a desired minimum is level of illuminance is achieved in one or more selected portions of the plan.

The lighting installation may be for an exterior area, such as a car park, sports ground, tennis courts etc. where a minimum level of illuminance may be desirable for personal safety, or security of property, or to allow e.g. sporting activities to take place at night or in conditions of low natural sunlight. Accordingly "floor" level might be, for example, ground level, not necessarily the floor of a building.

More typically however, the lighting installation will be for the interior of a building, such as commercial or industrial premises. In preferred embodiments, the lighting installation will be, or comprises, an emergency lighting installation for the interior of a building i.e. a system comprising a plurality of lighting units or luminaires which operate in the event that a main or routine lighting system fails wholly or in part. Typically, for an emergency lighting installation, the desired minimum level of illuminance to be achieved in one or more selected portions of the plan is that which meets or exceeds that specified in BS5266 part 7. In such embodiments, the one or more selected portions of the plan will comprise designated emergency exit routes from the premises.

The database of different lighting units or luminaires may comprise footprints for lighting units or luminaires which are adapted and configured for interior use only, or those adapted and configured for exterior use only, or may comprise some of both types. In some embodiments, the database will comprise footprints for a plurality of lighting units or luminaires adapted and configured for use as emergency lighting.

These are well-known to those skilled in the art and include both "standalone" lights and "maintained" lights. The lighting units or luminaires may comprise, as a light source, incandescent light bulbs, fluorescent tubes, LEDs or other suitable light source. A typical emergency lighting luminaire will comprise, in addition to one or io more light sources, a housing (with means for mounting the housing to a ceiling or other surface), and one or more of the following: a source of electrical power (which may be internal, such as a battery), associated circuitry (e.g. an LED driver circuit where the light source comprises an LED), a communications module (e.g. comprising a wireless receiver and/or transmitter), and a microprocessor or other is programmable controller.

The database will comprise a footprint for each lighting unit or luminaire for at least one predetermined mounting height. If a footprint for only one predetermined mounting height is provided, then this will preferably be at 2.0 metres or 2.5 metres, which are the mounting heights most commonly used for building interiors. It will be preferred however that the database will comprise a footprint for each lighting unit or luminaire at a plurality of different mounting heights, so that the database will be suitable for use in planning lighting installations in a wide variety of different situations.

Preferably the database will comprise a footprint for each lighting unit or luminaire at several predetermined mounting heights in the range 2.0 -8.0 metres. For example, the database may provide a footprint for mounting heights at 2.0, 2.5, 3.0, 4.0 and 6.0 metres. If desired, the database may comprise a limited number of the more commonly required footprints (i.e. most commonly-used lighting units or luminaires at the most commonly-used mounting heights), such that the database is of relatively small size and quick and easy to download, with a wider range of other footprints, less commonly-used, being available as optional "add-ons" or downloads which may be added to the initial, limited database.

The footprints in the database associated with the respective lighting units or luminaires may comprise a single value isolux or "contour". Alternatively, each footprint may comprise two isoluxes, or even more. A preferred footprint comprises from 1 to 3 isoluxes. Preferably, the footprint comprises a 0.5 Lux and/or a 1.0 Lux contour. Isolux contours of different values in one footprint may be distinguished by any suitable visual means including, but not limited to, use of different colours and/or o different patterns or densities of shading.

The footprints are importable into the computer-generated plan. The footprints may be in any convenient file format, but a.dxf format is preferred. The computer generated plan is a typically a CAD plan, as is produced by commercially-available design and drawing packages such as autoCAD. Typically the lighting unit or luminaire footprints are imported as one or more "layers" in a CAD drawing. The positions of the lighting units or luminaires, and hence their associated footprints, may then be adjusted in the CAD software "model space". Conveniently, different value isolux contours for each lighting unit or luminaire may be provided in different layers of the CAD drawing.

Conveniently each footprint is imported into the CAD drawing together with a product symbol for the associated lighting unit or luminaire responsible for the footprint, and preferably including some text. The text may, for example, identify or characterise the lighting unit or luminaire (e.g. by reference to a manufacturer's product code and/or trivial name) and/or may include an indication of the mounting height. The product symbol and/or text is conveniently viewable in the CAD drawing, at one of a plurality of different sizes, typically provided in separate layers of the CAD drawing, such that a user can turn on a selected layer, and turn off the other layers, to leave viewable the most appropriately-sized image and text for the selected "paper space" scale used to view the CAD drawing. In one embodiment, the product symbols and text are available to view in three different sizes, suited for viewing at 1:50, 1:100 or 1:200 scale respectively, which are the three "paper space" scales most commonly employed to view CAD plans.

As another refinement, in some embodiments, lighting units or luminaires of a particular type can be shown in the CAD drawing in a single layer, with lighting units or luminaires of other types being shown in other layers. Conveniently, a separate layer is available for each different type of lighting unit or luminaire included in the CAD drawing. In this way, a user can choose to view or omit lighting units or luminaires of different types. This is desirable since the CAD drawing images can io become a little confusing if all of the information is displayed relating to all of the lighting units or luminaires in an installation.

In addition to specifying minimum floor level illuminance, BS5266 also requires that an emergency light or luminaire is positioned within two metres of important parts of is an emergency escape route, such as a final emergency exit, emergency alarm call points, etc. Accordingly, in preferred embodiments, the invention also allows for the lighting units or luminaires to be imported into the CAD drawing, associated with a marker indicating a 2 metre radius around the lighting unit or luminaire. The marker may be, for example, a continuous or intermittent circle of 2 metres radius centred on the lighting unit or luminaire. As with most other features of the invention, this is conveniently provided in a separate layer of the CAD drawing, so that a user can choose whether or not to view these on the CAD drawing.

As an illustration, suppose it is desired to provide a room with a lighting installation providing a minimum illuminance of 0.5 Lux at floor level at all parts of the room.

The desired number and type of lighting units or luminaires may be selected from the database, and the corresponding footprints for the selected lighting units or luminaires (at the selected mounting height) are imported from the database into the computer-generated plan. Using the "model space" in the CAD software, the planner simply adjusts the footprints such that the 0.5 isolux from each lighting unit just touches, or overlaps to a small extent, the 0.5 isolux from the neighbouring lighting units or luminaires, with no gaps, so that the entire floor area of the room is lit with the desired minimum illuminance, and using the fewest possible lighting units or luminaires. The computer file is saved, with the corresponding positions of the lighting units or luminaires indicated.

As another illustration, suppose a corridor, constituting an emergency escape route, is to be lit with a minimum illuminance of 1.0 Lux at floor level. if the database footprints show both 0.5 and 1.0 isoluxes, then adjacent luminaires along the corridor can be positioned such that their respective 0.5 Lux contours overlap and come just up to the 1.0 Lux contour of their neighbour. Since the level of illuminance is additive, the overlapping 0.5 Lux contours provide a total illuminance level of LO Lux. In this io way the minimum number of luminaires, consistent with providing the desired minimum level of illuminance, can be incorporated into the lighting installation.

In a preferred embodiment, the method of the invention may additionally comprise the step of positioning one or more emergency escape route signs (which may be internally and/or externally illuminated) on the plan. By way of explanation, escape route signs must be of a size appropriate to the "maximum viewing distance" from which persons might need to see them. This size is set out (in BS5266), and depends, inter alia, on whether the sign is internally illuminated or externally illuminated. Accordingly, one may in similar manner devise a footprint for emergency exit or escape route signs, where the footprint corresponds to the "maximum viewing distance" for a sign of that type.

Thus, positioning the escape route or emergency exit sign footprints on the computer-generated plan will allow the planner to ensure that such signs are appropriately placed without exceeding their respective maximum viewing distances.

In a second aspect, the invention provides a method of installing a lighting installation, comprising a plurality of lighting units or luminaires, the method comprising the steps of selecting the desired number and/or positions for the selected plurality of lighting units or luminaires according to the first aspect of the invention as defined above; and installing the lighting units or luminaires at the desired positions.

The installing step is entirely conventional and does not form any part of the invention.

In a third aspect, the invention provides a computer database or computer library comprising a plurality of footprints, each footprint comprising at least one isolux contour at floor level for a particular lighting unit or luminaire when mounted at a particular mounting height, the database comprising at least one footprint for a plurality of different lighting units or luminaires. Preferably the database or library will comprise a plurality of footprints for each of a plurality of lighting units or la luminaires, each of the plurality of footprints corresponding to a different mounting height for a respective lighting unit or luminaire. The database or library will typically be stored in a digital electronic memory device such as a flash drive or the like.

is In a fourth aspect, the invention provides a computer, adapted and configured to perform the method of the first aspect of the invention. In particular, the computer may have a memory component which stores, permanently or temporarily, the database of lighting unit or luminaire footprints.

The various features of the invention will now be further described by way of illustrative example and with reference to the accompanying drawings, in which: Figures 1-4 are extracts from a CAD drawing, illustrating the principles of the method of the invention.

Example

The present example illustrates how the method of the invention can be used to select the number and position of luminaires in a lighting installation, such that a desired level of illumination can be achieved in parts of, or throughout, a plan space using the fewest possible luminaires of particular types.

Referring to Figure 1, there is shown a CAD drawing of the interior of a premises. The plan includes a perimeter wall 4, an open area 6, rooms 8, 10 and 12, and a stairwell 14. Two emergency exits 16, 18 are also provided.

The plan shows the position of a plurality of emergency luminaires 20-34, each indicated by a product symbol together with descriptive text.

For simplicity, in Figure 1 the light footprint 36 of luminaire 20 only is shown. The footprint comprises a floor-level 1.0Lux contour 38, and a floor-level 0.5Lux contour 40. The area within the 1.0Lux contour is densely hatched. The area within the 0.5Lux contour 40, but outside the 1.0Lux contour, is lightly hatched. (In addition, the different shading can be shown in different colours).

Also included in the plan are the positions of two emergency exit signs 42, 44.

Figure 2 shows the same plan as that illustrated in Figure 1, and the common components are indicated by common reference numerals. However, in Figure 2, an additional layer in the CAD drawing is turned on, such that for each of the emergency luminaires 20-34, there is also now shown a 2 metre radius circle around each luminaire, indicated by a broken line (one of which is indicated by reference numeral 46). The 2 metre radius circle can be used to ensure that there is an emergency luminaire within 2 metres of the emergency exits 16, 18, as laid down in BS5266. A further difference, relative to Figure 1, is that the layer showing the luminaire symbols and associated text has been altered to a larger scale, so that the symbols and text appear smaller than in Figure 1. This illustrates the feature whereby the scale of the symbols and text can be altered simply by switching between different layers in the CAD drawing.

Figure 3 shows the same plan as that illustrated in Figure 2, except that the plan now shows the light footprints associated with more of the emergency luminaires, but omitting those associated with the luminaires 22-26 in the open area 6. These three are all of one particular type of luminaire. These footprints can be omitted from the plan in this way simply by switching 'off' the layer that includes the footprints for the luminaires of that particular type.

Finally Figure 4 is the same plan as in Figure 3, but now including footprints for each of the luminaires 20-34. The number and position of the luminaires can be selected in "model space" using the CAD software to ensure that the footprints are adjusted to achieve the minimum desired level of illuminance throughout the relevant parts if the floor plan.

to As can be appreciated by the increasing complexity displayed in Figures 1-4, the ability to select which features are to be displayed in the CAD drawing, by providing them in different layers of the CAD drawing which can be turned on or off, is highly desirable, so as to simplify when necessary the number of different elements shown in the drawing.

Claims

Claims 1. A method of selecting the number and/or positions for a plurality of lighting units or luminaires in a lighting installation, the method comprising the steps of: (a) selecting from a database of different lighting units or luminaires, a selected plurality of lighting units or luminaires for use in the installation, the database comprising a footprint for each of the different lighting units or luminaires, the footprint comprising a io particular isolux contour at floor level for each lighting unit or luminaire at one or more predetermined mounting heights; (b) importing the relevant footprint for each of the selected plurality of lighting units or luminaires into a computer-generated plan of the building or location in which the lighting installation is to be installed; is and (c) adjusting the number and/or positions of the plurality of lighting units or luminaires such that the footprints thereof indicate that a desired minimum level of illuminance is achieved in one or more selected portions of the plan.

A method according to claim 1, wherein the lighting installation comprises an emergency lighting installation.

3. A method according to claim 1 or 2, wherein the desired minimum level of illuminance achieved in one or more selected portions of the plan complies with BS5266 part 7.

A method according to any one of the preceding claims, wherein the database comprises footprints for the different lighting units or luminaires for a plurality of mounting heights.

A method according to any one of the preceding claims, wherein the database comprises footprints for the different lighting units or luminaires for 2.0 and/or 2.5 metre mounting heights.

6. A method according to claim 5, wherein the database additionally comprises footprints for one or more additional mounting heights.

7. A method according to any one of the preceding claims, wherein the database has footprints comprising at least a 0.5 Lux and/or a LO Lux contour for each o lighting unit or luminaire.

A method according to any one of the preceding claims, wherein the footprints comprise two or more different isoluxes, which are visually distinguishable in the footprint when represented on the computer-generated plan.

A method according to any one of the preceding claims, wherein each of the plurality of the lighting units or luminaires is further associated in the plan with a marker indicating a 2 metre radius circle, which marker is preferably in a separate layer of the drawing.

10. A method according to any one of the preceding claims, wherein the method further comprises the steps of: (d) importing into the computer-generated plan the footprint of two or more emergency exit signs or escape route signs, wherein the imported footprint corresponds to the maximum viewing distance applicable to the selected emergency exit sign or escape route sign; and (e) selecting the number and positions of the emergency exit or escape route signs in the plan such that their maximum viewing distance is not exceeded.

11. A method according to claim 10, wherein the emergency exit sign or escape route sign footprints are selected from a library or database of such footprints.

12. A method according to any one of the preceding claims, further comprising the step of installing the selected plurality of lighting units or luminaires in the installation at their respective selected positions.

13. A method according to claim 12, as dependent on claim 10 or 1 1, further comprising the step of installing the two or more emergency exit or escape route signs at their selected positions.

RI 14. A method installing a light installation comprising a plurality of lighting units or luminaires, the method comprising the steps of: selecting the desired number and/or positions for the selected plurality of lighting units or luminaires according to the method of any one of claims 1 -1 3; and installing the desired number of lighting units or luminaires at the desired positions.

15. A method according to any one of the preceding claims substantially as hereinbefore described and with reference to the accompanying drawings.