Light Output Ratio (LOR) is a measure of the efficiency of a lighting fixture, calculated by assessing the amount of light that is ‘lost’ or trapped within the luminaire.
It is a useful unit of measurement for understanding the performance of various lighting products, as it provides an idea of how economical a fixture is. The formula for calculating LOR involves measuring the total light output of a fixture in comparison to the total light created at source within the fixture.
This calculation can be extremely useful in manufacturing, as it can help to determine how cost-effective certain lighting products are. Generally, the higher the LOR, the better the efficiency of the lighting product or system, with the least amount of wasted light lost within the product.
LOR is the abbreviation for the measurement of the Light Output Ratio from a light source.
The LOR helps us to judge which LED or any light souce is the most suitable for our needs. It helps us to determine how much usable light the product is actually providing, and thus how efficient it is at doing its job.
The Light Output Ratio is not to be confused with Luminous Efficacy, which calculates the amount of light delivered in comparison to the power used to create it. Although both do measure efficiencies, LOR compares just the ratio of light created and light delivered.
When a clear glass bulb has an LOR of 100%, we know that all the light created leaves the product and is delivered widely in all directions. However, when that light bulb is put inside for example a frosted glass bathroom wall light, inevitably some of that light will be lost as it bounces around behind the glass before escaping into the room.
If you measure with a lux meter the amount of light being delivered and compare it to how much it began with, you may be surprised to see how low the LOR is and how inefficient the light fixture has made the bulb.
The light output ratio is typically expressed as a percentage, with a higher percentage denoting better performance. Generally, a light output ratio of 70%-90% is considered to be a good range for most lighting products or systems.
If the LOR of the LED light is too low, it may indicate that the light is not performing as efficiently as desired.
So as an example,
When a recessed ceiling light has an LOR of 96%, it means just 4% of the light is lost within the inside of the product and as it passes through the lens.
When a bulb has an LOR of 80%, it means 20% of the light is lost and the product is delivering 80% of it’s origin lumen output.
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The light output ratio is an important measurement in the lighting industry, as it is used to measure the efficiency of lighting products and systems. By measuring the light output ratio, manufacturers can ensure that their products are performing as efficiently as possible, as well as ensure that the products meet industry standards.
The LOR can be useful to help consumers understand the performance of different lighting products, making it easier to make an informed decision when purchasing a lighting product or system.
Lighting products have a great effect on our environment, both through the amount of energy they use and the amount of light they emit. As such, LOR is an important measure of energy efficiency.
Therefore, by understanding the LOR of a product, we can better assess the potential environmental impact of that product.
Understanding LOR is particularly important in luminaire manufacturing, allowiing lighting manufacturers to better evaluate the energy consumption with the amount of usable light they are providing. This is especially important as different lighting products may have completely different levels of efficiency.
In order to calculate the light output ratio (LOR), the following equation is used:
LOR = (Actual Lumen Output/Initial Lumens from LED) x 100.
Light output or delivered lumens is measured as the amount of light exiting a product or system, while the light input is measured as the amount of light entering the system or product.
If a lighting product has an LOR of 90% or 0.90 and the initial lumens created are 1000lm, we can calculate that 90% of 1000 is 900 lumens.
We can work backwards too, if the product is specified with 900 delivered lumens with an LOR of 0.9, we know that the 10% lost is 100lm, combining to make 1000lm.
So we’ve seen that the LOR is an important measurement that provides valuable insight into the efficiency of lighting products and especially important in determining which lighting products are providing the most usable light and are the most energy efficient.
Knowing the LOR of a product can also help us to create a more sustainable lighting solution, as it allows us to assess which products are truly energy efficient and have the lowest environmental impact.
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