When the era of LED lighting arrived, there were many issues to consider regarding lighting levels. The main ones are light power and brightness. It used to be that more power meant brighter light, but these days a lot has changed.
Led light bulb
© Daniele Franchi
What the number of watts tells us
Electricity bills are a frequently discussed issue these days, it is the number of watts that is associated with it. Precisely because a watt is a unit of power. The number of watts consumed in a month is added up and from this comes our monthly charges. The number of watts must also be taken into account when the bulb fixture has a maximum wattage limit, or when we are replacing one of the bulbs connected on the same wire - such as Christmas tree lights. However, when it comes to the brightness level of our LED bulb - here we already have to take into account a different unit.
Old habits
For years we've heard about light in terms of bulb wattage. We may think of a 60-watt bulb in a lamp, when in fact we want that lamp to be as powerful as the old 60-watt bulbs. It's a kind of habit. We are so used to describing the amount of light in watts that most people don't stop to think about it. The amount of light we get from an incandescent bulb is the most important thing we look for when we buy a replacement.
Led bulb
© Fredrico Bottos
Lumens - the brightness of the light
The amount of light is not measured in watts, but in lumens. Labeled lm - lumens are a measure of the total amount of light visible to the human eye coming from an incandescent bulb or other type of light source. The higher the number of lumens, the brighter the lamp will shine. The number of lumens emitted by a bulb should be written on the package. We can assume for comparison - most older 60-watt incandescent bulbs produce between 750 and 1049 lumens, with the average being between 800 and 850 lumens. So the lumens seen on bulb packages in stores are easy to compare with these numbers to get an idea of how much light you'll get from a new bulb.
Efficiency
This is the amount of light a bulb emits compared to the amount of power it consumes. Once we have the lumens and watts, we can calculate the efficiency. This is the number of lumens per watt. However, it is rare that such information appears on the package.
Color temperature
Another value to consider is the color of light expressed in degrees Kelvin. This is again a separate topic determining whether the light emitted by the bulb is more white - cold, or more yellow - warm. We describe this topic in more detail in the article"How light color can affect your interior". In a quick summary, "soft white" light is usually around 2700K. "Bright white" light can be around 3500K. "Natural light" and "Daylight" can range from 4100K to 6000K.
