Buying Guides – Light Fitting Types – Fluorescent Fittings

When it comes to general lighting, fluorescent lamps have been popular since the 1950s. Nowadays, fluorescent tubes are commonplace in factories, schools, workshops, garages and in some parts of the home.

Compact Fluorescent Lamps (CFLs)

A relatively modern fluorescent fitting that is becoming increasingly widespread is the compact fluorescent light bulb (CFL). With many compact fluorescent lamps, the auxiliary electronics are integrated into the base of the lamp, which means they can be used in standard light bulb socket.

Fluorescent Tubes

Fluorescent light bulbs come in many shapes and sizes. They are identified by a standardised coding system that reveals valuable information about operating characteristics and physical dimensions. One key factor is a tube’s diameter, and this is given by the number following a ‘T’ (which denotes ‘tubular’). The figure refers to the tube’s diameter in 1/8ths of an inch, so, for example, a T8 tube would have a diameter of 1 inch.

T5 Fluorescent Tubes

The light output of T5 fluorescent lamps per unit length is almost identical to the larger T8 lamps. T5 lamps cannot be used as replacements for T8 lamps as they are slightly shorter. However, some luminaires can be adapted to accept either T5 or T8 lamps by changing the sockets and ballasts. The T5 is a versatile and effective source of illumination that is ideal for factories, schools, offices, supermarkets, underground railways etc.

Colour Characteristics

By using rare-earth phosphors, T5 fluorescent lamps achieve improved colour rendering and high efficacy. The correlated colour temperature (CCT) and colour rendering index (CRI) of the lamps is determined by the phosphors used in the manufacturing process. The CRI of T5 lamps can be specified from 70 to the mid-90s. For good quality lighting it is advisable to specify a CRI of at least 80.

T5 Ballasts

T5 lamps require special ballasts. These allow T5 lamps to operate at frequencies greater than 20 kilohertz and offer such features as instant start, rapid start and programmed start. In most cases, the T5 ballasts will not work with T12 or T8 lamps.

T5 HO lamps

‘HO’ stands for high output. T5 HO lamps produce more light than standard T5 lamps and are obtainable in higher wattages. HO lamps are available in the same diameter and length as standard T5 lamps.

T8 Fluorescent Tubes

The 32W T8 fluorescent lamp is becoming the standard for new construction and a replacement for 40W T12 fluorescent lamps. T8 lamps are easily available in a selection of straight and U-shaped designs. Compared to T12 fluorescent lamps, T8 lamps have the same 20,000 hour life expectancy and 32% lower typical energy usage, making them an ideal choice for offices, task lighting, schools, conference rooms, halls and retail outlets.

Colour Characteristics

T8 fluorescent lamps achieve both improved colour rendering and high efficacy by employing rare-earth phosphors. The correlated colour temperature (CCT) and colour rendering index (CRI) of the lamps is determined by the phosphors used in the manufacturing process. As with T12 lamps, T8 lamps are obtainable in a range of colour temperatures, including:

  • Warm (3000 K)
  • Neutral (3500 K)
  • Cool (4100 K)
  • Very Cool (5000 K)

‘Full Spectrum’ lamps are usually 5000K or more, and emit 10 to 20% of their output as UV light. The CRI of T8 lamps can range from 70 to as high as the mid-90s. For great lighting quality it is advisable to specify a CRI of at least 80.

T8 Ballasts

T8 fluorescent lamps require an electronic ballast that are designed specifically to operate lamps at a lower current than T12 lamps. When T12 lamps are replaced with T8 lamps, therefore, the ballast must also be replaced. The advantage of electronic ballasts is that they don’t flicker or hum and they use less energy than conventional ballasts.

T12 Fluorescent Tubes

T12 fluorescent lamps have traditionally been the most commonly used fluorescent tubes and have been installed in millions of homes, offices, retail outlets and schools. Although it was considered energy efficient in the 1970s, the T12’s reduced life expectancy, poor colour rendering and low light output often meant that more lamps and fixtures were usually needed, which generally offset the energy savings. At present, existing 40W T12 fluorescent lamps tend to be replaced by the more effective and more efficient 32W T8 fluorescent lamps.

Wide Range of T12s

The length of T12 bulbs varies from 15 inches all the way to 12 feet. They are available in two basic types: the standard and the high-output. Standard T12 bulbs have two pins on each end of the bulb. They provide a normal fluorescent light level for general applications. They should not be used in very cold areas, as they may fail to light up when temperatures get below 32. High Output T12 bulbs have one rectangular black plastic piece on each end of the bulb. The provide a higher level of light output than Standard T12 bulbs and use more wattage to do so. They are used in cold temperature locations, such as garages, outdoor signs, and freezers.

Please note – T12 tubes have now ceased production worldwide. We strongly advise stocking up on T12 tubes if you are not looking to change your light source in the short term..

2-Pin & 4-Pin

Compact fluorescent lamps (CFLs) are miniature versions of full-sized fluorescents that give off light that is similar to common incandescent bulbs rather than the fluorescent tunes used factories and schools. Current UK building regulations require a proportion of light fittings in newly built houses to be designed with 2- or 4-pin sockets, instead of the usual bayonet or screw fittings, so that they will only accept CFLs.

Bases & Sockets

The base of the CFL is the part that plugs into the electrical socket. Bases for CFLs are available in three forms: screw-in, 2-pin, and 4-pin.

  • Screw-in base – Identical to those used for incandescent bulbs, making them ideal for replacing screw-fit incandescent bulbs.
  • 2-pin base – Found on CFLs with pre-heat starting. Each 2-pin lamp has an integral starter and requires a separate ballast.
  • 4-pin base – Used on CFLs with rapid or instant start. 4-pin lamps require a separate control gear and starting device.

Pin-base CFL lamps are obtainable in a wide selection of outputs and sizes, making them an attractive option for both end-users and specifiers. Bear in mind that CFLs should not be used with the standard domestic wall-mounted dimmer switch. It is possible, though, to dim 4-pin lamps with specialist control gear and a compatible dimming controller.

Charles Barnett Managing Director

Charles started Lyco in 1995 with just 4 enthusiastic employees and has grown it considerably over the past 25 years. Charles is also the Managing Director of Lighting Direct and newly acquired Online Lighting. He now has a team of 50 lighting experts working on growing Lyco Group to be the UK leader in lighting for both businesses and homes. Away from the office he is a keen cyclist and is proud to have cycled 1017 miles from Lands End to John O’Groats to raise money for a new residential centre for adults with multiple learning difficulties.

Buying Guides – Safety & Installation

Electric lighting raises important safety concerns in two areas. Firstly, the installation of the lights inevitably involves dealing with electricity. The number of deaths and injuries caused by faulty electrical wiring – much of it installed by unqualified DIY enthusiasts – should act as a reminder to everyone of the importance of safety during all electrical lighting work.

Important Safety Regulations

In addition, the potential danger of electric lighting demands a basic knowledge of fire extinguishers, particularly those suited to electrical fires. It’s also important to remember that the light itself can pose a number of hazards. It may be too dim or poorly positioned so as not to illuminate essential areas sufficiently. This may cause discomfort due to glare, brightness or shadows.

Correctly installed lighting not only minimises the risk of harmful repercussions, but actively enhances the environment in which it is located.

Consulting a Qualified Electrician

The number of deaths and injuries caused by faulty electrical wiring (the majority of it installed by unqualified DIY enthusiasts) is reason enough to hire an experienced electrician, but not the only one.

Since 1st January 2005 any electrical work carried out in the home has to follow the strict rules set out in the Building Regulations ‘Approved Document P’.

Part P Building Regulations

Part P, as it is commonly referred to, gives you two choices when undertaking an electrical project in the home.

  • Employ a Part P qualified electrician to carry out the work and provide a signed record that it is all in accordance with the regulations.
  • Carry out the work yourself and ensure it is thoroughly inspected and subsequently approved by your local authority building inspector


What is Included in Part P?

Significant electrical work, such as rewiring a house or making additions to existing circuits in kitchens, bathrooms or outside the house will fall under Part P of the regulations. If you have any doubt over exactly what is included in the regulations, be sure to consult your local authority.

Qualified Electricians

When employing a qualified electrical contractor to do the work, your best protection against being let down by a ‘cowboy’ contractor is word-of-mouth recommendation.

As well as verifying their Part P status, look for an electrician that has completed projects successfully, on schedule and within the budget. Similarly, don’t be afraid to ask an electrician for references from past projects. If they are at all reluctant to give you the full details of a previous job then you would be well advised to look elsewhere.

Common Fitting Problems

A lamp’s light output diminishes over the time due to the effects of dust and general wear and tear. To ensure the desired level of luminance is maintained, a routine of maintenance and regular lamp replacement is necessary. In addition, there are other factors which affect the light quality emitted from lighting fixtures – some of which raise important health and safety concerns.

Glare

When brightness goes beyond maximum recommended levels, disturbing or debilitating glare can occur. There are a range of things that can be done to minimise this glare:

  • Use larger numbers of low wattage fixtures rather than fewer high wattage ones
  • Locate control panels and PC monitors away from windows or bright fixtures
  • Elevate high wattage fixtures above the normal field of view and aim some light toward the ceiling to disperse any glare.

Shadow

Shadows cast over any area where people require light can be overcome by using larger luminaires or simply increasing the number of light sources used.

Stroboscopic Effect

The stroboscopic effect (caused by the flicker of fluorescent lighting) creates the illusion of motion or non-motion; especially where moving machinery is concerned. Modern fluorescent tube design has largely overcome this potentially dangerous problem by significantly minimising flicker.

Colour Effect

An object that is blue for example will only appear this colour if the light falling upon it contains blue in its spectrum. Therefore it is important to bear in mind that colours can appear different under various types of lighting. For instance: a red object will appear brown under a sodium street light. With this in mind the choice of lamp is crucial if colour is important in the appearance or function of the room being illuminated.

Fire Extinguisher Types & Placement

Fire extinguishers are classed according to the different types of fire that each is designed to tackle.

  • Class A: Solids (paper, wood, plastic, etc)
  • Class B: Flammable Liquids (paraffin, petrol, oil, etc)
  • Class C: Flammable Gases (propane, butane, methane, etc)
  • Class D: Metals (aluminium, magnesium, titanium, etc)
  • Class E: Electrical Apparatus (electric heaters, industrial control equipment, etc)
  • Class F: Cooking Substances (oil, fat, etc)

The main body of each fire extinguisher is red and features more specific colour coding related to the class of each extinguisher.

Water Fire Extinguishers

  • Class A fires
  • Colour coding: Red
  • Cheapest & most widely used
  • Do not use on fires involving liquids or electricity

Foam Fire Extinguishers

  • Class A & B fires
  • Colour coding: Cream
  • An expensive, but more versatile alternative to water
  • Not recommended for electrical fires, but a safer option than water if inadvertently sprayed onto live electrical apparatus

Dry Powder Fire Extinguishers

  • Class A, B & C fires (most suited to running liquid fires – Class B)
  • Colour coding: Blue
  • The ‘multi-purpose’ extinguisher
  • Isolate the gas supply before extinguishing such a fire
  • Warning: when used indoors, powder can obscure vision and cause damage to goods and machinery

CO2 Fire Extinguishers

  • Class E fires
  • Colour coding: Black
  • Can also be used to extinguish class B liquid fires
  • Warning: with liquid fires, the CO2 extinguisher has no post fire security and the fire could re-ignite

Wet Chemical

  • Class F fires
  • Colour coding: Bright Yellow

Metal Fires

  • Class D fires
  • Colour coding: Blue
  • Specialist extinguisher for metal fires such as sodium, lithium, manganese and aluminium when in the form of swarf or turnings

Charles Barnett Managing Director

Charles started Lyco in 1995 with just 4 enthusiastic employees and has grown it considerably over the past 25 years. Charles is also the Managing Director of Lighting Direct and newly acquired Online Lighting. He now has a team of 50 lighting experts working on growing Lyco Group to be the UK leader in lighting for both businesses and homes. Away from the office he is a keen cyclist and is proud to have cycled 1017 miles from Lands End to John O’Groats to raise money for a new residential centre for adults with multiple learning difficulties.