Currently, lighting costs represent the 18% of energy consumption in homes and around the 30% in offices, according to electricity bills. An effective way to reduce these costs is by choosing the right type of lighting. If we select the right correct lighting For each space, we can save between 20% and 80% energy.
To achieve this saving, it is essential to choose Energy saving lightbulbs. These are classified according to their luminosity using as a unit of measurement the lumens, which express the amount of light emitted by the bulb.
On the other hand, with the incandescent bulbs (the oldest), reference would be made to the watts (W), which measure how much electricity The move to lumens as a unit of measurement not only allows us to better calculate the light we need, but also provides a more accurate way of assessing energy consumption.
What is a lumen?
To understand how to calculate lumens, we must first know what a lumen is. lumens are international unit of measurement used to quantify the luminous flux. This data provides us with information about the light power that a light source, such as a light bulb, emits.
For LED bulbs, there is a simple formula to estimate how many lumens a bulb offers:
- Actual lumens = number of watts x 70.
This factor of 70 is a standard value that applies to most LED bulbs on the market. For example, a 12W LED bulb would provide 840 lumens, a similar amount of light to a 60W incandescent bulb, but with a saving of XNUMX%. 48w.
How to calculate the appropriate lighting level for each room
Lighting should not be excessive or insufficient. It is essential that all spaces in the house are well lit according to their needs. Too much light can cause visual fatigue, while poor lighting can cause discomfort and strain the eyes.
To know how many energy-saving light bulbs are needed in a room, we can use the luxuries, which are a measure of the Light intensity. Lux is defined as the amount of light that falls on a surface of one square meter.
For example, if you have a 150 lumen bulb illuminating a 10 square meter room, the illumination level would be 15 lux.
Recommended lighting standards in a home:
There are general recommendations on the lighting levels that should be present in the different spaces of a home:
- Kitchen: Ideally, lighting should range between 200 and 300 lux for general lighting, and up to 500 lux in areas such as the counter, where food is prepared.
- Living Room: A range of 100 to 300 lux is recommended for general lighting. If you are going to read, it is advisable to have a focused light of up to 500 lux.
- Bedrooms: In adult bedrooms, levels of 50 to 150 lux are recommended for general lighting. For reading at the head of the bed, up to 500 lux are needed. In children's rooms, general lighting of up to 150 lux is suggested.
- Bathroom: In general, around 100 lux is sufficient, but in the mirror area levels of 500 lux should be reached for tasks such as shaving or applying make-up.
If we take these recommendations into account, it will be easier to provide each space with the appropriate level of light, which will contribute to improving comfort in each room.
To calculate the number of light bulbs needed in a room, simply multiply the square footage of the room by the recommended lux number and then divide that value by the number of lumens each bulb provides.
Watts to lumens conversion table
The conversion from watts to lumens can be confusing for those who are not yet familiar with this metric. For that reason, below is a comparison table showing the equivalence between lumens and watts for different types of light bulbs, including LED, incandescent, halogen and fluorescent:
| Values in lumens (lm) | LEDs | Incandescent | Halogens | CFL and fluorescent |
| 50 / 80 | 1,3w | 10w | - | - |
| 110 / 220 | 3,5w | 15w | 10w | 5W |
| 250 / 440 | 5W | 25w | 20w | 7W |
| 550 / 650 | 9W | 40w | 35w | 9W |
| 650 / 800 | 11w | 60w | 50w | 11w |
| 800 / 1500 | 15w | 75w | 70w | 18w |
| 1600 / 1800 | 18w | 100w | 100w | 20w |
The use of LED bulbs LED bulbs are becoming increasingly popular as they provide better energy efficiency. The ratio between lumens and watts is essential to determine the correct type of bulb and, above all, to save on the electricity bill. Considering aspects such as light intensity and the surface to be illuminated guarantees the visual comfort of the rooms, while ensuring responsible energy consumption.
Very well explained. Thank you