Light Visuals Neil Parslow shares his top tips for selecting the right products and systems for exterior hardscape and soft plant lighting.
We’re all aware of the environmental benefits and cost savings LEDs have to offer over traditional light sources. LED light fittings are available in a wide choice of qualities and styles, but the longevity of a garden lighting system will always be down to the products and installation methods used. It’s best practice to select the highest quality products your budget will allow, even if this means installing your lighting in phases, as this will help to spread the cost.
The right system for your lighting
Extra low voltage (ELV) lighting is the preferred choice for hardscape and soft plant lighting as it is safe and relatively simple to install. ELV lighting systems also have the benefit of using flexible cables such as HO5 and HO7RN-F rubber cables, rather than non-flexible steel wire cables (SWA) that are armoured and recommended for most mains 230V lighting. The use of smaller flexible cables makes it much easier to make ingress protection (IP) rated cable connections and is especially beneficial for recessed hardscape fittings, where the core drilled hole can be very small due to the compact size of modern recessed LEDs.
For larger gardens or where long drives and pathways require lighting it is usually best to install mains 230V cabling to the general location where the ELV lighting will be installed. From here, the cabling can be connected to the drivers/transformers to reduce the voltage down to a safer level. Due to the associated materials required, including cable glands and enclosures, 230V SWA cabling installations tend to be more expensive to install. This type of wiring system is also labour intensive compared to ELV systems.
"THE LONGEVITY OF A GARDEN LIGHTING SYSTEM WILL ALWAYS BE DOWN TO THE PRODUCTS AND INSTALLATION METHODS USED"
Choosing light fittings
Good quality products should always be used if possible as they will be well suited to the harsh conditions endured throughout the year. This also applies to the materials the products are made from, which include machined brass, copper, 316 marine stainless steel and powder- coated stainless steels. IP68 fixtures offer the best protection against ingress of water and are a must in areas susceptible to seasonal flooding or for submersing within water features and ponds etc. Some high-end LED fittings are available with anti-moisture barriers which act as a barrier preventing water from entering the luminaire if a poor connection has been made and will also eliminate moisture build up on the underside of the fitting’s glass lens due to capillary action through the cable.
Other qualities to look out for when selecting a light fitting apart from the colour temperature and lumen output is the colour rendering index (CRI), which states an LED’s ability to render colours accurately against a reference light source. As a guide, a CRI of 80 upwards is of acceptable quality. If you’re looking for discreet compact lighting, most fittings have the LEDs sealed in, and this has a negative effect on the environment as they are much harder to recycle.
There is, however, a handful of high-quality manufacturers who now offer much smaller fittings and use innovative replaceable LED boards, which can be changed easily by the end user in the field. This style of luminaire, although initially costly, does not require disposal when the LED eventually fails, thus saving money in the long term. Their fittings also have modular components to ease LED upgrade and recycling at the end of their life.