This is Part 1 in a 2-part series.
If you are in the business of recommending or specifying lighting for your clients, how do you know that you are getting the correct information from your lighting manufacturers? Everybody is trying to sell you a product based on some assumed efficacy, rated life or special feature. How do you know that you are getting the right data?
The adage of caveat emptor – let the buyer beware – certainly rings true when it comes to most lighting manufacturer’s data sheets. Most contain basic information on things such as form factors, lumen packages, energy used, options and accessories, and the L70 life of the luminaire.
At first glance, they all look great with impressive LPW calculations and L70s, so you happily specify the product only to be disappointed when it doesn’t perform the way that you thought it would. Remember, the client is eventually going to point some fingers. Do you want them to be pointing at you?
The following practice is very common when it comes to the LED high bay sector – it seems to be a liar’s paradise.
Be careful when looking at L70 data on spec sheets. Most manufacturers only show data at the TM21 25ºC level. That’s great if you are installing your high bay in a climate-controlled environment. However, what if you were installing the luminaire in an environment that regularly sees ceiling temperatures of 130ºF or 140ºF? Wouldn’t you want to know the L70 in those environments?
Without seeming overly cynical, most manufacturers don’t publish how well the fixture performs at its ambient temperature on their spec sheets because it doesn’t perform well at all. You can ask for the data from those companies. You might get lucky and actually get it. I would suggest that you should only deal with manufactures that are willing to provide that information freely or already publish it on their specification sheet.
As a specifier of luminaires, I would want to know how well the fixture is projected to perform at its ambient operating temperature. The value pricing that sometimes goes with lower-priced high bays could be costing your client more in the long run, in terms of maintenance and replacements.
Next, we will discuss the common practice of overstating the efficacy: