hen it comes to LED lighting fixtures, not only is there a wide range of products to choose from, but also a multitude of other important factors to consider. After all, a good LED unit is a serious investment!
Cost vs Output
When purchasing an LED fixture, you are essentially buying light! You can calculate how much light you are buying by simply dividing PPF (Photosynthetic Photon Flux) by the cost of the unit in Pounds. PPF measures the total amount of PAR (Photosynthetically Active Radiation) that is produced by a lighting system per second. This is all very technical stuff, so here’s an example:
If an LED Fixture has a PPF of 1518 μmol/s and costs £800, you would divide 1518 by 800. This gives a value of 1.9 μmol/s for each pound you have spent.
Fixture efficiency
One of the most common metrics you will see used with LED fixtures is the “fixture efficiency”, but what does this actually mean? In layman’s terms, this is how much energy is turned into light. This too can be calculated yourself by dividing the PPF of a fixture by the wattage. Here’s an example:
If an LED Fixture has a PPF of 1518 μmol/s and the wattage is 660W, you would divide 1518 by 660. This gives a value of 2.3 μmol/s for every Watt used, or to make it even simpler 2.3 μmol/J . J stands for Joules which is a unit of measurement for energy. The higher the value, the better the efficiency.
Product guarantee
An incredibly important aspect of purchasing an LED unit is the aftercare from the supplier & manufacturer of your chosen fixture. Do they have a decent guarantee period? Are they easy to get in touch with if you need some support? Are spares available easily?
What spectrum of light are you buying?
Technically speaking, this should be one of the primary things you look out for in an LED unit; after all, you are buying light, so you need to make sure that light has the correct spectrum of light for your needs! Sounds confusing, but over recent years growers have realised that full spectrum lighting with good amounts of red and blue light is important for optimum results. This means the light emitted by your fixture is as close as possible to the natural spectrum of the sun which as we all know, is pretty good at growing healthy plants!
Distribution of light
Secondly to the spectrum of your LED fixture, it is also important to consider the distribution of light that you will get. This means what area your LED will cover with beautiful, full spectrum light and how evenly said area will be lit. This is where LEDs really come into their own over traditional HID or compact LED fixtures that use lenses to distribute light, which can reduce the overall efficiency and therefore the quality of your grow!
An even distribution of light is important to achieve even growth over your growing area.
Fans/moving parts
The bane of growers since the dawn of the hydroponic industry has been heat and noise with large amounts of heat generated by high intensity horticultural lighting, and noisy extraction fans. With LEDs heat is still a factor, but with a high-quality unit it needn’t be a concern! High quality LED units will often use passive heat dissipation, where heat is removed using stationary heat sink fins rather than fans. This massively reduces the risk of failure, and the absence of fans eliminates a considerable amount of potential noise from your grow room.
Blue-Red-Peak-Spec-Graphs
Technically speaking, this should be one of the primary things you look out for in an LED unit; after all, you are buying light, so you need to make sure that light has the correct spectrum of light for your needs! Sounds confusing, but over recent years growers have realised that full spectrum lighting with good amounts of red and blue light is important for optimum results. This means the light emitted by your fixture is as close as possible to the natural spectrum of the sun which as we all know, is pretty good at growing healthy plants!
Distribution of light
Secondly to the spectrum of your LED fixture, it is also important to consider the distribution of light that you will get. This means what area your LED will cover with beautiful, full spectrum light and how evenly said area will be lit. This is where LEDs really come into their own over traditional HID or compact LED fixtures that use lenses to distribute light, which can reduce the overall efficiency and therefore the quality of your grow!
An even distribution of light is important to achieve even growth over your growing area.
Fans/moving parts
The bane of growers since the dawn of the hydroponic industry has been heat and noise with large amounts of heat generated by high intensity horticultural lighting, and noisy extraction fans. With LEDs heat is still a factor, but with a high-quality unit it needn’t be a concern! High quality LED units will often use passive heat dissipation, where heat is removed using stationary heat sink fins rather than fans. This massively reduces the risk of failure, and the absence of fans eliminates a considerable amount of potential noise from your grow room.
