Jen says there are a number of factors that will determine the right bulb to buy. The first is the dim angle of the bulb. "If you are replacing down lights you have to buy a directional bulb that casts down rather than an ambient 360 degree bulb."
Also be aware that if you use dimmers currently, you will need dimmable LED bulbs or fittings. Otherwise your lights will no longer dim.
Updating to LEDs becomes more difficult in houses fitted with halogen lighting. Halogens became popular for accent lighting from the 1980s/90s onwards and designers loved them, says Jen. Once the LED technology caught up and the price per unit began to drop, halogen fell out of favour.
Customers sometimes think they can simply replace the halogen bulbs with LEDs, but find that the latter flicker and die, says Jen. The transformers need changing to LED compatible ones.
Most home owners with halogen fittings who want to upgrade choose to replace the entire fitting with a new one in which the LED is integrated, says Jen. The downside of this is when they do eventually blow, an electrician is needed to replace them.
The advantage of replacing the transformer in the existing unit is that the bulbs can then be changed should they blow. This may work better in a rental property where tenants couldn't be expected to pay for a sparkie each time a bulb blows.
When choosing LED lights, it's important to consider the Kelvin colour temperature. This determines whether it's cool or warm light. Typically, says Jen, warmer colours are used in homes and cooler in offices.
A warm white LED will start from 2700K (Kelvin) and a cool white from 3500K to 4000K. Above this, the use will mainly be for commercial and hospitals.
LED lights are measured in lumens, not watts. LED bulbs usually range from 450 to 2000 lumens, which use the equivalent of 8 to 25 watts in the old measurements . "If it's for a living room, you probably need 500 to 600 lumens and if it's an office you probably need around 1000 lumens," says Jen.
The other decision to be made is the beam angle. A small beam angle would be used for task or accent lighting, he says. For more general lighting, look for a wide beam angle that distributes light across the room.
There are some additional advantages of replacing halogen lights with LED, other than just power savings, although that's 85 per cent according to Energywise.
Halogen bulbs operate at a higher temperature. This means that insulation cannot be laid over them in the ceiling, which in turn means a loss of heat through the roof where there are gaps in the insulation around the halogen fitting.
Property investor Andrew Bruce got so sick of calling an electrician to one of his rental apartments that he arranged for his electrician to replace the halogen bulbs in the entire apartment with LEDs.
He figured that the new fittings would pay for themselves over time with fewer call-outs.
"It wasn't a massive apartment and 20 to 30 per cent of the light bulbs had gone. I thought rather than get a sparkie to replace a couple of fittings I would do all of them."
The cost of replacing a house lot of R80 or halogen bulbs and fittings varies according to the number of fittings in the house and the cost of the electrician if needed. It's not unusual, says Jen, for a customer to spend around $600 at a time on a three-bedroom house to buy bulbs and/or fittings.
Jen's last piece of advice is to look at the warranty on the products you are buying.
"LED normally has life expectancy of 30,000 hours. If you run (it) eight hours a day it should last 10 years or so. You should get LEDs with at least three years of warranty."