This very much comes down to personal preference. Personally I prefer to fit more than is required, and then divide them up onto different switches. This will create different lighting effects. For example, if you are putting the downlights into a kitchen you could have the downlights that are placed over the worktops on one switch and the other downlights that are illuminating the rest of the kitchen on another switch - possibly a dimmer. This then means that you have good task lighting where needed and controllable mood lighting elsewhere.
However, there are still some important factors to remember.
Without having any technical information about your particular room, use the following ‘Rule of Thumb’. This best describes a kitchen, but can be adjusted for any room in your house.
Firstly, make sure the Downlights that are going to be closest to your walls are no more than 600mm to 800mm into the room. The reason for this is that 600mm is the standard measurement for the depth of your floor cupboards. This will mean that once the Downlights are fitted, no shadows will be created over the area that you are working.
You should now work out the position of the other lights by spacing them at intervals of between 1200mm and 1500mm. From these figures you should now be able to calculate how many fitting will be in a row and how many rows you will need.
12v downlights are on their way out now with lots of manufacturers discontinuing their 12v ranges. I use to advise 12v downlights in kitchens and bathrooms due to the 12v lamps producing a slightly higher lumen level, with 230v halogens fitted elsewhere in the house which produced a warmer light.
However now LED’s lamps are taking over! Now I will only recommend 230v mains rated downlights as they are a lot easier to fit and LED GU10 lamps are available in different kelvin levels and are either dimmable or non-dimmable.
If you are installing downlights then do not fit 12v downlights as LED lamps generally do not work as well as 230v mains rated LED’s.
Ceilings provide an important barrier that helps to prevent the spread of fire and noise between the floors of a building. Installing recessed downlights punctures this barrier and can reduce the effectiveness of this safety barrier.
Installing fire rated downlights helps to protect your premises from the effects of both fire and noise pollution and aids compliance with new building regulations governing the installation of downlights. Made from intumescent materials, fire rated downlights seal the gap between the ceiling and the fitting to offer up to 90 minutes protection against the spread of fire into the void spaces within your ceiling / loft space.
Fire rated downlights are more expensive than non-fire rated downlights. However, the worst decision you can make is to buy cheaper models that look exactly the same only to find out from the electrician fitting them, that building regulations require fire rated downlights for that situation. Then fire hoods will have to be bought and you would now find that you have spent more money in the long run.
Personally I feel it is best to always go for the safest lights on the market. Fires cost lives, surely that is worth a few pence more to fit fire rated downlights.
Having the right IP rated downlights is also a very important factor. Please see ‘What is IP Zoning’ to see whether you will need an IP rated downlight. Water and electricity do not mix. Again IP rated downlights cost a fraction more but by paying a little extra you could save yourself from being electrocuted, or causing the contacts in the fitting to corrode. This could lead to a short circuit and possibly a fire.
Firstly, you should read ‘Part P – What is it?’ as this will answer whether or not you can legally carry out the work you wish to do. Some people will always have a go, no matter what their level of competence is.
Electricity is dangerous and could kill you. I will always suggest to get an electrician in to do the work required, but if you are determined to do some electrics yourself please remember to be safe at all times and follow some basic safe isolation procedures before proceeding:
Once the wiring has been pulled through the hole the downlight can be wired. To fit the downlight into the hole, hold the two springs back against the sides of the downlighter and push up into the hole. The springs then lie flat on the top of the ceiling holding it in place.
This all depends on what you have in your tool box already! Please see the below list of what tools I have used in the past for fitting downlights. Some of them you might not need but can often prove useful.
Lighting circuits are usually on 6-amp circuit breakers often known as MCB’s (Miniature Circuit Breakers). To calculate how many Amps are loaded onto the lighting circuit a simple calculation is made. UK voltage is 230 volts, now assume that each light on the circuit is 100 watts, and you have got 12 lights on the circuit.
The calculation would be:
Total Watts ÷ Voltage = Amps
So taking the above information the calculation would be:
1200 watts ÷ 230 volts = 5.22 amps
So now we can see that the above described lighting circuit is using 5.22 amps meaning that the circuit breaker of 6 amps is not being overloaded.
Now to confuse things a little but very helpful on lighting circuits when you are wishing to add more lights. On lighting circuits once you have worked out the amps you can now apply a thing called Diversity, which for lighting circuits is 66% of the total load. So to work out this calculation we can do the following sum:
5.22amps ÷ 100 x 66 = 3.45 amps
So now we can see that we are able to add more lights to the circuit now that diversity has been applied to it.
Remember to carry out your calculations before you start any work!