Thursday, July 14, 2016

Industrial LED Lights - How Much can you save?

So when you convert from Metal Halide or High Pressure Sodium to Industrial LED Lights, how can you calculate the savings. Here is a quick guide to help you sort it out.

How can you calculate the savings when you convert to LED?

Three important factors to consider
  1. Hours On. How many hours per year are your lights turned on? The higher it is, the larger the payback. If your lights are turned on 12 hours a day / 365 days a year, that translates into 4,380 hours per year. If your lights are always on, that's 8760 hours per year.
  2. Electricity Cost. Your utility charges you a rate, adds in their fees and send you a bill. To calculate your "real" rate with all fees added, take the total amount charged and divide it by the kilowatt hours you used.
  3. Rebates? This is the rebate your utility might give you. Some utility rebates are generous. Some not so. For new Industrial LED Lights and LED retrofit kits, there may be rebates available for DLC Qualified Products.
So now you have the 3 factors, 1 and 2 will be used to calculate the savings. Let's look at this scenario. Say you have (100) 400W High Pressure Sodium Area Fixtures, like a flood light. They are on 12 hours a night 365 days a year. The cost of electricity is .12 kw/h.

Your Current Lights consume...
  • Each light consumes 455W (55W extra by the ballast)
  • The watts consumed each day is: 455 X 12 = 5,460 watts per day per fixture
  • Convert to kilowatts by dividing by 1000 = 5.46 kw
  • In 1 year, 5.46 X 365 = 1992.9 kw used per fixture
  • Multiply that by your utility rate 1992.9 X .12 = $239.14 per fixture per year
  • If you have 100 fixtures, your cost is $23,914.00
LED Lights consume...
  • Using a 105W LED retrofit kit, each kit consumes 105W
  • The watts consumed each day is: 105 X 12 = 1,260 watts per day per fixture
  • Convert to kilowatts by dividing by 1000 = 1.26 kw
  • In 1 year, 1.26 X 365 = 459.9 kw used per fixture
  • Multiply that by your utility rate 459.9 X .12 = $55.18 per fixture per year
  • If you have 100 fixtures, you cost is $5,188.00.
    You will save $18,726 per year on these 100 lights.

Sunday, July 10, 2016

A Simple Calculation: Converting from High Pressure Sodium to LED

So how many lumens of LED do you need to convert from High Pressure Sodium to LED? Do you just replace lumen for lumen? Well, we are here to say NO! If you do that, you will increase the light levels in the area by 5X.

Here's the math. So when you read the foot candles of a light, you are measuring foot candles with a light meter and that is called a photopic measurement. This has been the standard since light meters were invented. Well, slight problem. First, light meters pick up everything. Including those spectrum's like UV and IR that we can't see. But it collects them and adds them into the total light being measured. Problem is that is not how we perceive light.

Humans are not light meters, we see light in a different way. And so there are times when we demo a LED light up against a High Pressure Sodium Light and ask "Which is brighter"? and they say the LED. And then we bring out the light meter and it says the HPS is brighter. And now we have a confused customer.

And that us when we explain Scotopic lumens, or the lumens we perceive as people. And it is different than what a light meter reads. And what are we trying to solve. Lighting for people or lighting for meters? So its good that the smart lighting scientists thought of this and came up with a ratio of how we perceive light by type of lights.

For example, 2100K High Pressure Sodium gets a ratio of .40 and 5000K LED gets a ratio of 1.8. So how does this help? So lets take a HPS bulb producing 40,000 photopic lumens. Multiply it by the .40 S/P ratio, and the scotopic lumens is 16,000 lumens. Take a LED Light that produces 10,000 lumens, multiply it by 1.8, and it produces 18,000 scotopic lumens. That's right, we are saying that 5000K 10,000 LED Lumens is brighter than 2100K 40,000 HPS lumens, in terms of how we perceive the light. Put a light meter under each light source and it is going to tell you a different story. Let your eyes judge and you will choose the LED.

For more information on S/P ratios, check out this page for a complete listing of S/P ratios by light source.

Friday, July 8, 2016

7 Reasons Why LED Tubes are Better than Fluorescent Tubes

One of the best energy savings and cost reduction retrofits you can do is to replace your existing fluorescent tubes with LED tubes. Here are the top 6 benefits of doing the conversion

1. Lower energy consumption. Converting from a 4ft T8 32 Watt fluorescent tube to a 15 Watt LED Tube saves you 50%+ on your utility bill for the power consumed by lighting. Fluorescent tubes need a ballast to operate, and ballasts consume about 15% extra over the 32 watts the tube consumes (about 4 watts)

2. Lower maintenance costs.
LED Tubes are rated for about 50,000 hours of life and warrantied for 5 years (DLC Qualified). If your office runs lights 10 hours a day and average 20 working days a month, your LED tubes will work for over 17 years. 

3. Reduced AC Load.
LED runs cool. LED Tubes run cooler than fluorescent tubes. You will require less AC to offset the heat generated by fluorescent tubes and ballasts. 

4. Unbreakable. They are the perfect replacement for shatterproof fluorescent tubes. Be careful though, some of the new LED tubes are glass tubes, make sure you purchase the plastic tubes for this application.

5. Flicker Free. Fluorescent tubes flicker. This flickering has many health issues associated with it, including:

    - headaches
    - eyestrain
    - seizures (epilepsy)
LED Tubes do not flicker. The older a fluorescent tube gets, the more likely it is to flicker and strobe.

6. No Mercury. Fluorescent tubes contain mercury. Drop a fluorescent tube and that's a problem. Read what the EPA thinks of what you should do to clean up a fluorescent tube after it breaks. LED Tubes do not contain mercury

7. No humming. Ballasts hum, the older they are, the more they make noise. LED tubes do not hum