Setting up your house and you are looking to buy the best tube lights or bulbs for it? With lots of options available, it can be a difficult task to buy one and decide which one is good. In the past, we mostly used to get normal bulbs or fluorescent tube lights which eventually graduated to CFLs and energy-efficient fluorescent tube lights. But the current times are that of LED tube lights or bulbs. There are many more energy-efficient options available in India today and at Bijli Bachao our efforts are always to help make consumers aware about them. The modern energy-efficient LED Tubelights or bulbs may be slightly more expensive as compared to old options but they do provide a lot of value. In this post, we will discuss the costs or prices of these options, their wattage and the benefit that you can get from them. We will also provide a buying guide and some products that you can buy to help you save electricity. We will also discuss how much lighting is good for your room and how to decide on the amount of lighting.
First, let’s take a look at all the old and new options:
The traditional yellow light bulbs, invented by Thomas Edison at the beginning of 20th century had illuminated our houses till the end of 20th century and were available in various variants: 40W, 60W and 100W, are the most inefficient in terms of energy consumption. 90% of the energy they consume is lost as heat and only 10% is converted into useful light.
Although they are still quite inexpensive (Rs 10/-) and only a few of the households still use it, but they are energy guzzlers. Many countries in the world have stopped producing them. Even if they are still there in working condition in your household, it makes a lot of sense to replace them with energy-efficient options just from a cost-saving perspective. Do not forget that the incandescent lamp increases the heat load of the room for airconditioning.
The fluorescent lamps are better than Incandescent bulbs (50-70% better in providing the same amount of light) and they have been there in the market since quite some time. It started coming in the form of tube lights (something which most of us have known since our childhood) and later graduated to come in the form of CFLs so that it can be retrofitted in the holder of the incandescent lamp.
A typical fluorescent lamp has a ballast (to first provide high voltage to strike an arc and then stabilize the current through the lamp) and a tube. In past tube lights used to come with electromagnetic ballast which caused the lights to flicker on start. Later on, developed electronic ballast which prevents the fluorescent lamps to flicker. Electromagnetic ballast ( an now only for historical study) consumes a significant amount of electricity than an electronic ballast. Most tube lights today have electronic ballast.
With time, tube lights were d in various developed in various variants: T12, T8 and T5. These numbers represent the diameter of the tube (i..e T12 is 3.81 cm 12/8″, T8 is 2.54 cm or 1 inch and T5 is 1.69cm or 5/8″) of the tube light. The smaller the number, the higher the efficiency. A T12 tube light with an electromagnetic ballast typically consumes 55W of electricity but a T5 with electronic ballast will consume only 28W of electricity (comparison is for a 4 feet tube light). Thus a T5 provided about 50% electricity saving over a regular T12 tube light. T8s are typically 38W tube lights and are better than T12s. Even though T5s were a little expensive during their heydays but still a payback was within a year if T8 or T12 is replaced. Also, their life was quite good and they last for 3-4 years at least. Many companies give 1-2 year replacement warranty on T5s. Thus the payback happens within the warranty period. However, Fluorescent Tubelights are becoming obsolete these days and are getting replaced by LED Tubelights.
CFL (Compact Fluorescent Lamp)
CFLs have been regarded as the best energy saving option in our country for quite some time. CFL is a variant of fluorescent lamps (or tube lights) but developed with a purpose of the retro fitment of the incandescent lamp. CFLs act as a point source of light (light originating from one point) whereas tube lights are line source (tube lights have bigger lengths) and thus the area covered by tube lights is a lot more than that of CFLs. This is the reason why a lot of people feel that CFLs produce lesser lights than tube lights. Even with equal wattage (2x14W CFLs) the amount of light is felt lesser than a T5 tube light (of 28W) because of CFL being point source. CFLs being compact in size provide options to create smaller (lower wattage) bulbs that can cater to locations where tube lights provide extra brightness (more than required). CFLs provide up to 70% energy savings over a typical incandescent bulb. Although a little more expensive than an incandescent, payback happens within a year. But the CFL heydays are over and replaced by retrofitted LED lamps.
Incandescent (beginning of 20th century) and Fluorescent (beginning of mid 20th century) Lamps are now left only for engineering studies with limited use in a specific area and the field of illumination engineering is now completely taken over by LED lights (beginning of 21st century) till such time more energy-efficient source is discovered.
LED (Light Emitting Diode)
LEDs are the latest and most efficient lighting option which is available in the market. Their electricity consumption is less than that of CFLs and fluorescent lamps for the same amount of light. LEDs also are long-lasting with a life of about 10-25 years and their performance remains the same throughout their lifetime (Tubelights and CFLs get dim with time). Although a little expensive during the period of first launched and up to 2015, a major shift has taken when Government of India directed Energy Efficiency Servies Ltd to undertake large scale production and rates dropped to Rs. 38 per 9 W LED Lamp and production skyrocketed to the level of 4 Cr. per month as compared to just 10 lakhs earlier. Ideally, they are a long-lasting option as the life of LEDs is about 10 years. But local drivers installed in a luminaire may fail earlier. If you encounter a failed LED luminaire, try to see if your electrician can change the driver and get it working again.
LED Tubelights are replacements for regular tubelights. They are a line source of light and thus they cover a larger area. These days several options of LED Tubelights are available in the market: 18 Watt, 20 Watts, 22 Watts, etc. In terms of light output (or lumens output), a 20 Watt LED Tubelight is similar to an old 40 Watt T-8 or 27 Watt T-5 tubelight.
LED Bulbs are replacements for CFLs and incandescent bulbs. When planning for replacement, look at the base B 22 pin type, E27 screw type and E15 screw type used for decorative lighting. They are a point source of light and thus cover a smaller area. If you are looking to replace your existing CFL, then you can look at the table below to get a comparison:
Best Lamp in the year 2019
From the above, it is evident that using LED lamp is the best option while selecting the lamp for your house. The major advantage of LED as compared to any other source of light is:
- The high energy efficiency of 100-120 lumen/watt and going up to 200 lumen/Watt as per the research in progress.
- No warm-up delay and starts instantaneously with no flickering which is very commonly observed in fluorescent lights.
- Frequent switching on and off does not reduce life.
- Retro fitment fixtures develop to replace using the mounting of the existing fitting.
- LED chips and fixtures developed to overcome the disadvantage of beam angle.
- Adaptability for long-range of voltage fluctuation from 160 to 280 V.
- Decorative lights developed with many options of using LED in any combination, shape etc.
Buying guide for a Lamp
The wattage of the bulb or tube light has been traditionally used as the measure of the amount of light produced by it, but watts does not represent the actual amount of light produced. The amount of light produced is represented by a term called lumen. So to compare two lights, one should compare the lumen output of the lamp.
Lumen output defines the efficiency of the lamp. Lumen is the output and watt is the input and lumen/watt defines the efficiency of the lamp. Wattage just helps one estimate power consumption.
The angle of delivery of light
The angle of delivery of light is the beam angle produced by the light source. LED is a point source but it is the lense and the luminary which makes it usable for large applications requiring spotlight, floodlight, wide floodlight and very wide floodlight.
Colour rendering index (CRI)
This is the factor that measures to what extent the light illuminated is close to real light. CRI is measured between 0-100. If the CRI is high the quality of the light is high. If the CRI is low, the quality of the light is low.
Colour temperature in Kelvin
Color temperature is a way to describe the light appearance provided by a light bulb. It is measured in degrees of Kelvin (K) on a scale from 1,000 to 10,000. Typically, Kelvin temperatures for commercial and residential lighting applications fall somewhere on a scale from 2000K to 6500K. The table given below describes the quality of colour temperature towards the light
|Color Temperature||Quality of Light|
|4000K-4500 K||Less Yellowish Light|
The higher we go on to the Kelvin scale, we will progress to yellow lights, white light, and blue lights. Incandescent and Halogen lights range between 2500K – 3000K. Direct sunlight has the equivalent of 4800K. Daylight is found around 5600K. A cloudy sky or cool white can be found between 6000K-7500K. A clear blue sky can be found at 10,000K.
How much light is required for your room?
Amount of lighting required for a room depends on the size of the room and the purpose of the room. Intricate tasks require more lighting and just moving around the room requires much less light. The amount of light required in an area is defined as “LUX” (also a popular brand of soap) level that is equal to lumens/area (lm/m2). Below table gives a good idea of LUX level for various tasks:
(More details available at: http://www.engineeringtoolbox.com/light-level-rooms-d_708.html)
So if you have a room that is 10 ft x 10 ft (which is 9.29 m2) and you want to do easy office work in the room, then the amount of light required in the room is 250 x 9.29 which is about 2400 lumens. one single tube light can achieve this. The lumen of every lamp is given on the rating plate of the lamp for your you do your own calculation.
If you have a small area of a square meter and you use it for computer work, then a 12-watt CFLor 8 Watt LED is good for it.
|Activity||Illumination (in Lux i.e. Lumen/m2|
|Public areas with dark surroundings||20-50|
|Simple orientation for short visits||50-100|
|Working areas where visual tasks are only occasionally performed||100-150|
|Warehouses, Homes, Theaters, Archives||150|
|Easy Office Work, Classes||250|
|Normal Office Work, PC Work, Study Library||500|
Task-based lighting can be done in a room accordingly.
When do you waste electricity?
When you use more lumens in a room than required then you are wasting electricity for extra lighting. There are multiple cases when this happens:
- More lights are put in a room than desired.
- Lights are hidden on concealed. Many times this is done with false ceilings to decorate the room.
- At times there is some obstruction for the lights and extra lights have to be put to accommodate for the less light.
If you want to save electricity, make sure that any of the above is not happening.
Does brightness of bulb remain the same throughout its life?
No. It decreases with time for most types of bulbs. Lights become less bright as they age. LEDs are known to have similar levels of light throughout their life and in fact, they have long lives. The typical life of:
The range above is for an average quality bulb to a good quality bulb.
The greener option
LED is the greenest option available in all forms of lighting. And that is because:
- It does not contain any mercury, which is harmful to the environment, unlike the fluorescent bulbs and lights.
- It lasts much longer (about 10-20 years) and thus their disposal is less of a concern.
Fluorescent lights, on the other hand, contain mercury that is harmful to the environment and their disposal is a concern. And this is a problem with both CFLs and fluorescent tube lights.
10 best brands of LED lamp manufacturer in India
The 10 best brands of LED lamps we have identified are 1. Phillips 2. Osram 3. Havells 4. Wipro 5. Bajaj 6. Syska 7. Surya 8. Crompton 9. Moser Baer & 10. Oreva. It may be difficult to identify the best out of the lot, and therefore, consumers generally compare based on the price and the one which meets its basic requirement. There is a good discount available on Amazon/Flipkart when one order for higher quantity and can be seen on online link. The household requirement of LED lamps are generally covered under the requirement of (a) LED bulb (b) LED tube light (c) downlight/spotlight (d) panel light (square or circular) (e) mirror light and (f) decorative lights. The requirement from (a) to (d) are general purpose and easy to choose based on the price and many models of various manufacturers available in the market.
BEE Star Labelling of LED Lamps
Checking the BEE star labelling is one of the best options for a consumer to bank upon. As of now, the lumen efficiency in lumen/watt for 3-star between 90-105, 4-star between 105 to 120 and 5-star above 120. As of now, the LED lamps are available which qualify 3-star or few make with 4-star and the day is not far off when 4 and 5 stars rated LED lamps will be available with ease. As per the claims made by few of the make in their product specification on amazon, lumen/watt of 140 has been claimed but without any five-star rating as per BEE. Few of the makes particularly Wipro claims UL(Underwriters Laboratories) testing to LM 79 or 80 which is an indication of complete testing by an independent agency with repeat testing for quality assurance at intervals.
Chose LED Lights for your house on Amazon
Popular brand and efficiency of between 90 and 105 lumen/watt or 3-star rating
LED bulb is designed to replace the traditional design of incandescent or CFL lamp. There are traditional three types namely (a) B22-Pin type with lamp base diameter of 22 mm and used for traditional lighting; (b) E14-screw type with lamp base diameter of 14 mm and used for decorative lighting (c) E27-screw type with lamp base diameter of 27 mm and used for traditional wall/ceiling lighting. Now the manufacturers (e.g. Phillips) have also come out of mounting of tube light in these holders. Here are few of the commonly used sold at the amazon e-commerce website.
These lights are generally used for spot/cabinet lighting
LED Panel Lighting
Panel lighting is generally mounted on the ceiling with uniform distribution to avoid direct lighting. Available in round and square shape of different wattage and dimensions.
Infographics for better understanding
About the Author:
Abhishek Jain is an Alumnus of IIT Bombay with almost 10 years of experience in corporate before starting Bijli Bachao in 2012. His passion for solving problems moved him towards Energy Sector and he is keen to learn about customer behavior towards Energy and find ways to influence the same towards Sustainability. More from this author.