HPS is the well-known and traditional grow light for all crops, so why should you take the “risk” of choosing LED
for your nursery – and is it more beneficial to grow plants under LED lights? Read here why our controllable LED lamps
are a smart choice and why more and more growers consider LED to be a better solution than HPS
Let’s start with the needs of the plant
The dashed lines on the graphs indicate the active area of photosynthesis. Note the difference in the spectra (colors) of HPS and LED respectively. It is important to know that especially red, some blue and very little green/yellow are important for plant growth. Also notice the radiant heat on the HPS graph: this is a very expensive form of heating.
HPS or LED?
Below you will find statements about both HPS and LED – and each statement should be seen as being held against each other – meaning HPS versus LED. This will give you an insight into the difference between the two types of lamps.
HPS
- Significant heat radiation from the lamps at the top of the greenhouse = costly heating.
- Often need for ventilation due to heat radiation from the lamp.
- One spectrum (color) should fit the needs of all plants.
- Not possible to change the spectrum and thus the amount of blue light.
- Traditional lighting strategy = limited opportunity for production optimization.
- On/off bridge.
- Low efficiency μmol/w/s.
- Decrease in bulb light output over time – but energy costs are unchanged.
- Bulbs with shorter lifetime, approx. 10,000 h.
- Maintenance is necessary for a stable output.
LED
- Minimum heat input ensures better heat control = financial savings.
- Optimal use of insulation curtains and CO2 supply.
- Control of spectrum (color) and light intensity needed for the different stages of all plants.
- Less need for retardant when using blue light (results in a more compact plant).
- Optimized production time.
- Dynamic lighting control = energy savings.
- High efficiency μmol/w/s.
- Constant light output from diode with unchanged power consumption.
- Long-life diodes, approx. 70,000 hours.
- Virtually no maintenance.
Heat circulation – HPS vs. LED
– and why it is obvious that using HPS will result in significant heat loss
HPS explanation:
The radiant heat from the HPS lamps will increase the temperature in the top of the greenhouse. This heat will circulate to the temperature sensor, which will close/reduce the bottom heat. This results in “cold roots” which affects the growth of the plants. To avoid this situation, open the top windows, the temperature drops and allows the temperature sensor to open the bottom heat. As a result, the open windows will cause a loss of heat and CO2.
LED explanation:
At an operating temperature of only 45°C for DGT by Senmatics LED lamps, the climate conditions for the plant are significantly more optimal. Underheating can be active in all conditions to ensure active roots and result in optimal growing conditions. The significantly lower operating temperature of the LED lamps results in less ventilation and prevents heat and Co2 losses.
Savings when using LED!
When considering an investment in LED lamps, people usually only consider the actual cost
– how much does a lamp cost and what will the return on investment be? But there are many more savings and benefits to consider than just the cost of purchase and installation. Are you aware of these?
Direct financial savings
- Electricity consumption
- Light intensity and spectral composition are optimized according to the plant’s needs
(thinking like a plant) - The same constant light output year after year
Secondary savings
- Better control of heat in the greenhouse consisting of:
– Better heat management (ratio between top and bottom heat)
– Less overproduction of heat so the curtain can be used as an insulation curtain
– Closed windows ensure a controlled CO2 level - Less use of chemicals means healthier plants (and protects the environment)
- Optimized production time (higher yield)
- Greater uniformity of plants results in higher efficiency and less labor.
More and more gardeners are now focusing on these extra savings (which equals profits)! Are you remembering to factor them in too? We believe it’s an important factor to keep in mind and should be factored into any cost/benefit analysis when considering an investment in an LED installation.
One final note
We hope this information will help you through the process of deciding whether you want to keep the traditional HPS lamps or future-proof your nursery with LED lamps. If you need further information or assistance, please feel free to contact us by phone or email.
You can also find a lot of valuable information by visiting our other pages on our website.
We look forward to discussing the benefits and advantages of LED lamps for your business.
