Good planning is the key when designing dark sky friendly lighting
By Andrew Hind
We’ve all seen pictures of boathouses at night — brightly lit, gorgeous and inviting. Turns out, what makes for beautiful imagery is also bad for the
Light pollution is found in every city and town in North America. And despite its natural splendour, Muskoka isn’t immune. If you’ve ever been blinded by the intense glare of a neighbour’s overlit boathouse, or had your view of the night sky masked by the unnatural glow radiating from town, you’ve been the victim of light pollution. And it isn’t just stargazers and nighttime boaters who suffer.
“Light pollution has all sorts of negative effects and it’s not just about viewing stars in the night sky. More so, it’s about human health, safety, energy wastage and adverse effects on native species,” explains James Solecki, owner of Integra Works, the first dark sky friendly light supplier in Canada. Solecki is passionate about dark sky friendly lighting and is a recipient of the 2003 Muskoka Stewardship Award, presented by the Muskoka Heritage Foundation for efforts in promoting and maintaining the natural dark sky environment.
Many people regularly have their sleep disturbed by over-bright exterior lighting or even sky glow. Because our bodies evolved to sleep in natural darkness, night lighting can cause sluggishness, lack of concentration, depression or irritability. There are even some studies, Solecki explains, linking light pollution with a number of diseases and conditions. As well as seriously affected individual health, this can lead to lost work efficiency, accidents and expensive health care.
Light pollution wastes huge amounts of money and energy. It’s estimated that in Canada alone street lighting throws over $1 million of unnecessary light into the night sky every year due to poor design. On a more personal level, badly designed, overpowered and inefficiently installed residential lighting sucks money out of your pocket. And generating all this wasted power creates huge amounts of CO2 and other greenhouse gases.
Even nature suffers the effects. “Wildlife aren’t immune to light pollution, either,” explains Solecki. “We’re just now beginning to understand the effects light pollution has on native species. All living creatures are used to periods of complete darkness and losing that undermines health. Light pollution also affects things like migration patterns and wildlife behaviour patterns.”
Fortunately, it’s possible to effectively light your nighttime environment while at the same time eliminating, or at least
greatly reducing, light pollution.
It starts with rethinking the way we use light. We tend to think that bright lights make it easier to see at night, and the brighter they are, the better we can see. It turns out that’s not true.
The brightness of the light doesn’t matter as much as the contrast between the light areas and the dark areas. Our eyes are more comfortable and efficient in lower, more even light levels, says Solecki: good
planning and proper light direction count for much more than simple brightness.
Of course, any outdoor light fixtures should be dark sky friendly. “There are a lot of different dark sky friendly fixtures you can use to light your home or cottage that can help save you money and reduce light pollution,” says Craig Clairmont, owner of BC North Electric. “But they all have one thing in common: they are down lights and come with hooded reflectors to cut off lighting where it’s not needed and prevent unnecessary light shining upwards,”
You can further enhance the environmental friendliness of dark sky fixtures, or indeed any lighting system, by purchasing a passive-infrared (PIR) sensor. A PIR sensor triggers lights only when they are needed, reducing running costs and pollution. Sensors can be adjusted to keep the light on for a variable length of time, often as short as a few minutes and as long as half an hour. To be environmentally friendly, adjust the sensor for the shortest time that suits your needs. Because they are triggered by heat signatures, PIR sensors can occasionally “cry wolf” by turning on unnecessarily. To prevent this, make sure to site them away from heat sources that may trigger them.
A cheaper alternative is to use low wattage and power-saving bulbs, preferably compact fluorescent bulbs. Do you really need a 300-watt halogen bulb to light your deck? A well-directed 100w light could be better, cheaper to run and less polluting.
Once you’ve got the right fixtures, ensure they’re well aimed. Lights should not beam out on a vertical plane. Instead, they should be tilted down as far as possible, creating subtle illumination not unlike the glow cast by the moon. Only the area to be lit, a pathway, for example, should be covered by the beam. In addition, site the fixture as high as you can, as this enables less tilt and provides safer, more even light.
The simplest way to reduce light pollution is to switch lights off when they’re not needed. It saves you money and can help you and everyone else enjoy the beauty of the night sky again.
“Being dark sky friendly is about being efficient with our use of light, nothing more,” says Solecki. “The benefits to our health and the environment we love in Muskoka far outweighs the effort involved.”