​LIGHT SPECTRUM
Bilberry fixtures are equipped with a full white spectrum supplemented by a 660 nm red diode, which enhances photosynthesis efficiency, facilitates plant transition to the generative phase (flowering and fruiting), and improves root formation. They also feature a 730 nm far-red diode, which enhances the effect of the red diode. The Bilberry fixture offers 3 spectra optimized for specific growth phases. As indicated by scientific publications and our own research, plants require different light spectra for optimal growth at various stages. Therefore, the vegetative phase utilizes a full spectrum with relatively higher levels of blue light. The selection of cooler light temperature is based on the fact that an excess of red and far-red light during the vegetative phase adversely affects plant growth. The spectrum for the generative phase includes an increased amount of 660 nm red light (approximately 50%) and a small addition of 730 nm far-red light (a few %), which supports flower and fruit development and seed formation. Additionally, there is a full spectrum with the addition of UVA 390 nm light available. This frequency stimulates plants to produce secondary metabolites such as nutrients and aromatic substances, thereby improving the quality of the final product (yield). The utilized spectra include adequate amounts of far-red and green light, which have high leaf penetration, reaching lower layers of the plant and thereby enhancing photosynthesis efficiency and accelerating plant growth. Separating spectra for different growth phases improves cultivation efficiency and increases both quantity and quality of yield.

HEAT DISSIPATION FROM LEDS 
The efficiency of illumination and the rate of efficiency loss depend on the quality of the LEDs and the effectiveness of heat dissipation from the LEDs to the surroundings. In Bilberry fixtures, we employ passive heat dissipation through aluminum plates, high thermal conductivity thermal paste, an aluminum profile made from a high thermal conductivity alloy, formed into a radiator with a large surface area for air contact, and a structural coating ensuring additional surface contact with the surroundings. The structural coating also enhances heat emission from the fixture. According to measurements on Bilberry fixtures, the junction temperature of the semiconductor (LED) at room temperature is approximately 85°C, and the maximum operating temperature of the LED is 120°C. Therefore, a buffer is applied to allow for an increase in ambient temperature of over 30°C. The lighting fixtures have undergone tests in environments with temperatures reaching 50-60°C in summer, operating reliably and continuously for nearly 5 years. According to manufacturers' documentation, the LEDs used in Bilberry light sources are rated to shine for 100,000 hours. Furthermore, due to the design of the LED panels (3 spectra) in the Bilberry fixture, only a portion of the LEDs operate simultaneously, extending the lifespan of the fixture.

LED BINs 
Bilberry utilizes SMD LEDs from leading manufacturers such as Samsung and Osram, which are currently among the best on the market in terms of efficiency and durability. During LED production, LEDs of varying quality are manufactured and grouped by LED manufacturers into categories known as BINs. In Bilberry fixtures, we use LEDs from the highest quality BINs.

OPTIWHITE GLASS
In Bilberry fixtures, we previously used diffusive glass with additional anti-reflection coatings. However, we discontinued this solution due to nearly 20% light loss compared to low-iron Optiwhite glass, which we currently use. Optiwhite glass absorbs only about 4% of light. Based on our observations, diffusive glasses are well-suited for greenhouse roofing but result in significant light loss when used in lighting fixtures, leading to a notable decrease in fixture efficiency. For safety, Bilberry uses tempered glass, which shatters into small, blunt pieces if broken.