Difference between revisions of "Outdoor lighting"
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==Lighting types== | ==Lighting types== | ||
| − | The available lighting types are covered in | + | The available lighting types are covered in [[:Category:Lighting|Lighting category]] articles. The types most often used outdoors are [[filament lamp]], linear [[halogen]], [[CFL]] and [[Discharge lighting|sodium]]. [[LED]]s are now becoming a realistic option too for city gardens. |
| − | * Low pressure sodium | + | * [[Discharge lighting|Low pressure sodium]] |
| − | ** extremely high energy efficiency | + | ** extremely high energy efficiency, can put out 10x as much light per watt as filament lamps |
** pure yellow light | ** pure yellow light | ||
| − | ** 9 minute warmup time so only for photocell use | + | ** Long 9 minute warmup time so only for photocell use |
| − | * High pressure sodium | + | * [[Discharge lighting|High pressure sodium]] |
** very high energy efficiency | ** very high energy efficiency | ||
** golden orange light | ** golden orange light | ||
| − | ** slow warmup, so only for photocell use. | + | ** slow 2 minute warmup, so only for photocell use. |
| − | * White sodium | + | * [[Discharge lighting|White sodium ]] |
** a variation of HPS. Whitish light, but lamp colours tend not to match each other well. Good where one is used, less so where more are used. | ** a variation of HPS. Whitish light, but lamp colours tend not to match each other well. Good where one is used, less so where more are used. | ||
| − | * HID | + | * [[Discharge lighting|HID]] |
** very high efficiency | ** very high efficiency | ||
** good white light, but pick the right colour temperature bulb. | ** good white light, but pick the right colour temperature bulb. | ||
** lamps can explode at end of life. | ** lamps can explode at end of life. | ||
| − | * Linear fluorescent | + | * Linear [[fluorescent]] |
** very high efficiency | ** very high efficiency | ||
| − | ** can be fitted under soffits, but not very warm & homely. | + | ** can be fitted under soffits, but not very warm & homely appearance. |
| − | ** Pick an electronic ballast suitable for sub-zero starting. | + | ** Pick an electronic ballast suitable for sub-zero starting, or it might fail to light in a cold winter. |
** Can be used on PIR, tube life suffers quite a bit in hours, but not in days of use. | ** Can be used on PIR, tube life suffers quite a bit in hours, but not in days of use. | ||
| − | * CFL | + | * [[CFL]] |
** medium to high energy efficiency | ** medium to high energy efficiency | ||
** Light output can be reduced and warmup time prolonged in subzero weather. Lamps immune to this are available. | ** Light output can be reduced and warmup time prolonged in subzero weather. Lamps immune to this are available. | ||
| − | ** PIR use reduces bulb life | + | ** PIR use reduces bulb life, but the more expensive electrodeless CFLs are immune to this issue. |
| − | * LED | + | * [[LED]] |
| − | ** high energy efficiency | + | ** high energy efficiency, but limited power |
** Light quality tends to be cold | ** Light quality tends to be cold | ||
** Some LEDs fade with use | ** Some LEDs fade with use | ||
** Various colours available for parties etc | ** Various colours available for parties etc | ||
| − | * Mercury | + | * [[Discharge lighting|Mercury]] |
** horribly cold white light | ** horribly cold white light | ||
** medium energy efficiency | ** medium energy efficiency | ||
| + | ** under a minute warmup time | ||
** obsolescent | ** obsolescent | ||
| − | * Halogen, linear | + | * [[Halogen]], linear |
** low energy efficiency | ** low energy efficiency | ||
** often far too bright | ** often far too bright | ||
| − | * Halogen reflector lamps, low voltage | + | ** Using them on PIR keeps run costs down |
| + | * [[Halogen]] reflector lamps, low voltage | ||
** can light individual trees & other features | ** can light individual trees & other features | ||
** don't overdo the wattage, 50w is generally excessive outdoors | ** don't overdo the wattage, 50w is generally excessive outdoors | ||
| − | * Halogen reflector lamps, mains | + | * [[Halogen]] reflector lamps, mains |
** as above but lamps fail easier & earlier and produce less light. | ** as above but lamps fail easier & earlier and produce less light. | ||
** Best avoided. | ** Best avoided. | ||
| − | * Filament | + | * [[Filament lamp]] |
| − | ** lowest energy efficiency, high run cost if kept on. Best | + | ** lowest energy efficiency, high run cost if kept on. Best used on a PIR because of this. |
| + | |||
==Control methods== | ==Control methods== | ||
| Line 51: | Line 54: | ||
===PIR=== | ===PIR=== | ||
PIRs (passive infra-red) detect the movement of warm bodies, and switch off after a short time of no detected movement. These are usually the best option for outdoor lighting, but like anything they have their issues. | PIRs (passive infra-red) detect the movement of warm bodies, and switch off after a short time of no detected movement. These are usually the best option for outdoor lighting, but like anything they have their issues. | ||
| + | |||
| + | PIRs shouldn't stare into the sun, doing so can affect their ability to detect consistently. However sometimes its the one practical option, and they sometimes do work ok like this, sometimes not. | ||
* detector angle & positioning | * detector angle & positioning | ||
| − | The switching device in a PIR is either a relay or a triac. Triacs are a bit cheaper, but are prone to being killed when a filament lamp blows (halogens | + | The power switching device in a PIR is either a relay or a triac. Triacs are a bit cheaper, but are prone to being killed when a filament lamp blows (especially with halogens). Also triac PIRs can misbehave with CFLs. Relays click when switching, triacs are silent. Relay PIRs are compatible with all current and future lighting types, triacs can only be counted on to work with filament lamp types. |
| + | |||
| + | Modern PIRs also detect outdoor light level, and don't come on if its daylight. Check the setting on this, it can come preset way off. | ||
| + | |||
| + | Extending the detecting range of a PIR is unlikely to be possible, due to the way the detector and its lens work. If you need more range, fit a 2nd PIR detector in a suitable place. | ||
| − | + | If a PIR is triggered by pets, pointing the detector up a bit more may stop this. | |
===Timer=== | ===Timer=== | ||
| Line 67: | Line 76: | ||
Photocells can also be combined with a timer, if for example you want lighting on from dusk to midnight. | Photocells can also be combined with a timer, if for example you want lighting on from dusk to midnight. | ||
| + | |||
| + | ===Mini PIR=== | ||
| + | Mini PIRs with a short detection range are useful where the house is very close to the street. They're the same as a conventional PIR but without the fresnel lens. | ||
| + | |||
| + | ===Beam break=== | ||
| + | In situations where a PIR is unworkable, such as a shallow porch that opens onto the pavement, its possible to use a beam break detector. When someone walks into the porch, they break the light or IR beam crossing the entrance, but passers by don't trigger a response. Beam break detectors are now uncommon, having been almost entirely displaced by PIRs. You may have to use a security beam break detector with a separate relay. | ||
===Split control=== | ===Split control=== | ||
| Line 78: | Line 93: | ||
Lighting of unsuitable wattage is often found, especially when linear halogen is used. The prime offender is 500w linear halogens. End users should also be aware that that LEDs & all types of discharge lighting put out several times as much light per watt than filament lamps. | Lighting of unsuitable wattage is often found, especially when linear halogen is used. The prime offender is 500w linear halogens. End users should also be aware that that LEDs & all types of discharge lighting put out several times as much light per watt than filament lamps. | ||
| − | |||
===Glare=== | ===Glare=== | ||
Its best to avoid lighting up roads, neighbouring properties, adjacent hillsides etc. It annoys people, and wastes light youre paying for, so you need a higher wattage lamp at greater cost to do the job. It can also create an accident risk on roads, and consequent legal liability. | Its best to avoid lighting up roads, neighbouring properties, adjacent hillsides etc. It annoys people, and wastes light youre paying for, so you need a higher wattage lamp at greater cost to do the job. It can also create an accident risk on roads, and consequent legal liability. | ||
| Line 84: | Line 98: | ||
Carriage style light fixtures can have glass panels removed and replaced with sheet ali or mirrored glass to cut down on lost light. No, not all of them :) | Carriage style light fixtures can have glass panels removed and replaced with sheet ali or mirrored glass to cut down on lost light. No, not all of them :) | ||
| + | ===Dimming fittings=== | ||
| + | One of these can cost you thousands in wasted electricity. See [[Dimmed PIR Lights]] for explanation. | ||
| + | |||
| + | ===Height=== | ||
===Light pollution=== | ===Light pollution=== | ||
Any light that heads upwards is money and energy wasted, and causes problems for astronomers. Many decorative fittings are far from ideal in this respect. High power fittings such as halogens should always be set to eliminate light pollution. | Any light that heads upwards is money and energy wasted, and causes problems for astronomers. Many decorative fittings are far from ideal in this respect. High power fittings such as halogens should always be set to eliminate light pollution. | ||
| Line 107: | Line 125: | ||
===Climbing plants & fire=== | ===Climbing plants & fire=== | ||
Lamp types vary widely in their ability to set fire to plants. Linear halogens run extremely hot, and plant life must always be kept away from them. Sodiums & LEDs run fairly cool, and can be nestled among foliage. | Lamp types vary widely in their ability to set fire to plants. Linear halogens run extremely hot, and plant life must always be kept away from them. Sodiums & LEDs run fairly cool, and can be nestled among foliage. | ||
| + | |||
| + | |||
| + | ==Relamping== | ||
| + | Lamp life: | ||
| + | * [[Discharge lighting|Low pressure sodium]] | ||
| + | * [[Discharge lighting|High pressure sodium]] | ||
| + | * [[Discharge lighting|White sodium]] | ||
| + | * [[Discharge lighting|HID]] | ||
| + | * Linear [[fluorescent]] 20,000 hours, but much less on a PIR | ||
| + | * [[CFL]] 3,000-12,000 hours, but much less on a PIR | ||
| + | * [[LED]] widely varying lifetimes, 15,000hr typical, some up to 50,000hr | ||
| + | * [[Discharge lighting|Mercury]] | ||
| + | * [[Halogen]], linear 1,500hrs | ||
| + | * [[Halogen]] reflector lamps, low voltage 1,500hrs | ||
| + | * [[Halogen]] reflector lamps, mains | ||
| + | * [[Filament lamp]] 1,000hrs | ||
| + | |||
| + | Overlapping areas: if you may be unable to relamp promptly, placing fittings with overlapping lighting areas enables good lighting to be maintained with some dead bulbs. | ||
| + | |||
| + | Difficult to reach fittings should definitely use long lived lamp types. | ||
| + | |||
==Wiring== | ==Wiring== | ||
===Old installs=== | ===Old installs=== | ||
Regulations have become a good bit more demanding in the 17th edition. Lots of old installs exist using T&E clipped direct, which has 2 issues. There is a theoretical risk of cable degradation, but practically it doesn't seem to be a problem. Such [[cable]] can be cut into by secateurs. | Regulations have become a good bit more demanding in the 17th edition. Lots of old installs exist using T&E clipped direct, which has 2 issues. There is a theoretical risk of cable degradation, but practically it doesn't seem to be a problem. Such [[cable]] can be cut into by secateurs. | ||
| + | |||
| + | Low voltage lighting is a lot easier to install for a novice DIYer that doesn't know much about wiring regulations. | ||
| + | |||
==See also== | ==See also== | ||
Revision as of 03:56, 9 November 2011
Lighting types
The available lighting types are covered in Lighting category articles. The types most often used outdoors are filament lamp, linear halogen, CFL and sodium. LEDs are now becoming a realistic option too for city gardens.
- Low pressure sodium
- extremely high energy efficiency, can put out 10x as much light per watt as filament lamps
- pure yellow light
- Long 9 minute warmup time so only for photocell use
- High pressure sodium
- very high energy efficiency
- golden orange light
- slow 2 minute warmup, so only for photocell use.
- White sodium
- a variation of HPS. Whitish light, but lamp colours tend not to match each other well. Good where one is used, less so where more are used.
- HID
- very high efficiency
- good white light, but pick the right colour temperature bulb.
- lamps can explode at end of life.
- Linear fluorescent
- very high efficiency
- can be fitted under soffits, but not very warm & homely appearance.
- Pick an electronic ballast suitable for sub-zero starting, or it might fail to light in a cold winter.
- Can be used on PIR, tube life suffers quite a bit in hours, but not in days of use.
- CFL
- medium to high energy efficiency
- Light output can be reduced and warmup time prolonged in subzero weather. Lamps immune to this are available.
- PIR use reduces bulb life, but the more expensive electrodeless CFLs are immune to this issue.
- LED
- high energy efficiency, but limited power
- Light quality tends to be cold
- Some LEDs fade with use
- Various colours available for parties etc
- Mercury
- horribly cold white light
- medium energy efficiency
- under a minute warmup time
- obsolescent
- Halogen, linear
- low energy efficiency
- often far too bright
- Using them on PIR keeps run costs down
- Halogen reflector lamps, low voltage
- can light individual trees & other features
- don't overdo the wattage, 50w is generally excessive outdoors
- Halogen reflector lamps, mains
- as above but lamps fail easier & earlier and produce less light.
- Best avoided.
- Filament lamp
- lowest energy efficiency, high run cost if kept on. Best used on a PIR because of this.
Control methods
Switch
Lights get left on by mistake, and the switch is often not where you need it. Wasteful of energy & money, inconvenient, and a trip hazard. Pets paws can be badly injured by being trodden on in the dark.
PIR
PIRs (passive infra-red) detect the movement of warm bodies, and switch off after a short time of no detected movement. These are usually the best option for outdoor lighting, but like anything they have their issues.
PIRs shouldn't stare into the sun, doing so can affect their ability to detect consistently. However sometimes its the one practical option, and they sometimes do work ok like this, sometimes not.
- detector angle & positioning
The power switching device in a PIR is either a relay or a triac. Triacs are a bit cheaper, but are prone to being killed when a filament lamp blows (especially with halogens). Also triac PIRs can misbehave with CFLs. Relays click when switching, triacs are silent. Relay PIRs are compatible with all current and future lighting types, triacs can only be counted on to work with filament lamp types.
Modern PIRs also detect outdoor light level, and don't come on if its daylight. Check the setting on this, it can come preset way off.
Extending the detecting range of a PIR is unlikely to be possible, due to the way the detector and its lens work. If you need more range, fit a 2nd PIR detector in a suitable place.
If a PIR is triggered by pets, pointing the detector up a bit more may stop this.
Timer
As dawn & dusk times varies considerably, timers are wasteful of energy, and the unnecessary on time reduces lamp life in days (though not in hours). Timers should be replaced with a photocell when a light needs to be on all night, or with a PIR when the lamp type and application are suitable for that.
Photocell
Switches on when it gets dark, switches off when it gets light. Take care over setting the light level switching points, they're often left set way off. Clean the light detecting cover occasionally.
Photocells run lamps much more of the time than PIRs, and a PIR is preferable when suitable.
Photocells can also be combined with a timer, if for example you want lighting on from dusk to midnight.
Mini PIR
Mini PIRs with a short detection range are useful where the house is very close to the street. They're the same as a conventional PIR but without the fresnel lens.
Beam break
In situations where a PIR is unworkable, such as a shallow porch that opens onto the pavement, its possible to use a beam break detector. When someone walks into the porch, they break the light or IR beam crossing the entrance, but passers by don't trigger a response. Beam break detectors are now uncommon, having been almost entirely displaced by PIRs. You may have to use a security beam break detector with a separate relay.
Split control
Where more than one light fixture is used, if they cover different areas its often an advantage to control them separately, reducing total energy use.
Multiple control
Large sites can benefit from multiple control methods, eg an 18w sodium lamp on all night providing low level security lighting, and white lighting on a PIR for security and access.
Common issues
Wattage
Lighting of unsuitable wattage is often found, especially when linear halogen is used. The prime offender is 500w linear halogens. End users should also be aware that that LEDs & all types of discharge lighting put out several times as much light per watt than filament lamps.
Glare
Its best to avoid lighting up roads, neighbouring properties, adjacent hillsides etc. It annoys people, and wastes light youre paying for, so you need a higher wattage lamp at greater cost to do the job. It can also create an accident risk on roads, and consequent legal liability.
Carriage style light fixtures can have glass panels removed and replaced with sheet ali or mirrored glass to cut down on lost light. No, not all of them :)
Dimming fittings
One of these can cost you thousands in wasted electricity. See Dimmed PIR Lights for explanation.
Height
Light pollution
Any light that heads upwards is money and energy wasted, and causes problems for astronomers. Many decorative fittings are far from ideal in this respect. High power fittings such as halogens should always be set to eliminate light pollution.
Placement
Positioning a light fitting above the entrance door has the advantage that it lights up the visitor's face, and doesn't create glare for the person indoors. A light further away can do the exact opposite on both counts.
Relamping
Relamping fixtures mounted high up can be a real issue. This is especially true if you're liable to reach pension age in the current property. If you need a lot of light, a few lights within reach are a lot easier to maintain.
MICC
MICC cable is unique in that its insulation sucks water vapour out of the air, and its too easy to make end seals that don't remain vapour tight long term. This type of cable is best avoided for outdoor lighting.
Water
All fittings should shed rain coming from above, and drain any rain that gets in out of the bottom. Sometimes fittings are seen that don't obey these basics, and they have a habit of eventually filling with water and taking out the power.
Globe breakage
Glass globes can be shattered if the screws retaining them are tightened at all. Its best to leave a very little bit of movement.
Screws on fixtures
Screws rust and jam. Screws in aluminium fixtures corrode the ali as well. Replacing them with tied wire avoids this problem.
Climbing plants & fire
Lamp types vary widely in their ability to set fire to plants. Linear halogens run extremely hot, and plant life must always be kept away from them. Sodiums & LEDs run fairly cool, and can be nestled among foliage.
Relamping
Lamp life:
- Low pressure sodium
- High pressure sodium
- White sodium
- HID
- Linear fluorescent 20,000 hours, but much less on a PIR
- CFL 3,000-12,000 hours, but much less on a PIR
- LED widely varying lifetimes, 15,000hr typical, some up to 50,000hr
- Mercury
- Halogen, linear 1,500hrs
- Halogen reflector lamps, low voltage 1,500hrs
- Halogen reflector lamps, mains
- Filament lamp 1,000hrs
Overlapping areas: if you may be unable to relamp promptly, placing fittings with overlapping lighting areas enables good lighting to be maintained with some dead bulbs.
Difficult to reach fittings should definitely use long lived lamp types.
Wiring
Old installs
Regulations have become a good bit more demanding in the 17th edition. Lots of old installs exist using T&E clipped direct, which has 2 issues. There is a theoretical risk of cable degradation, but practically it doesn't seem to be a problem. Such cable can be cut into by secateurs.
Low voltage lighting is a lot easier to install for a novice DIYer that doesn't know much about wiring regulations.