FAQ about installing a laser cinema projector: what’s the luminous efficacy of laser projectors and
Posted by Tom Bert
Following How to get the laser projector into my booth? and Which laser safety instructions do I need to take into account? we will now answer the last frequently asked question: what’s the luminous efficacy of laser projectors and why is cooling important here?
Of our RGB laser projectors, the brightest model (60,000 lumens) consumes approximately 6.5kW. The two chillers add 3kW in total. The brightest member of our laser phosphor projector portfolio, the DP2K-20CLP (20,000 lumens), consumes 2.9kW, including cooling units.
Electricity bill savings
The first thing you see is that the lm/W numbers are an order of magnitude better than the Xenon alternative. Compared to a standard 20,000lm lamp-based projector, the DP2K-20CLP is almost TWICE as efficient. For an on-par lumen target, your electricity bill will drop significantly. If you use laser projection to achieve brightness improvement, your power budget could increase and extra supply might be required.
What's the impact of the efficient cooling on the booth ambient?
The questions we frequently get are about how the efficient cooling impacts the booth ambient: air exhaust and booth temperature. The unique thing about laser cooling – compared to on-par lumens levels – is that the airflow is higher than with lamps, but the air temperature is lower. A commonly used unit here is CFM: cubic feet per minute. This just gives you an indication of the emitted air volume but not on how warm that exactly is.
The temperature is important because it defines how much thermal load needs to be exhausted or absorbed. A better unit for this is BTU/hr. We also have the calculators available to determine the CFM and BTU/hr impact for your booth.
In general, our customers are taking two approaches:
You follow the CFM spec (which is higher for laser) and directly exhaust the warm air.
You keep the CFM capacity you had with your lamp-based projector and let the extra air flow in the booth. Because of the low overall BTU/hr value and because the overflow is just part of the total exhaust, it’s easy to absorb this via extra booth HVAC capacity in the latter case.
Both options are equally good, it just depends on the practicalities of which parameter you have easiest access to (exhaust CFM or HVAC BTU/hr).
Installing a laser projector (RGB and laser phosphor) involves some practicalities that are slightly different from installing a lamp-based projector. With over 200 units installed or being installed, our worldwide partner network is experienced on this matter. We support partners and exhibitor with the right tools and in-house expertise. The opening of all-laser multiplexes on all continents confirms that laser is the choice for the future and will soon become the de facto standard.
About the author
Tom Bert is a senior member of the Product Management team in Barco’s Entertainment division; he is responsible for the digital cinema servers and projectors. Tom joined Barco in 2006 as Research Engineer for Barco’s Technology Center. In 2009, he joined the Product Management team in the Digital Cinema division. Since 2015, Tom has been actively working on digital cinema servers and projectors and he has been promoted to Sr. Product Manager. Based in Belgium, Tom has international experience in display technology. He holds a PhD degree in Engineering from Ghent University.