A lot of time we are asked what is the equivalent LED product to convert from Metal Halide, High Pressure Sodium or Mercury Vapor. And a lot of time, we have a product in mind that works based on past experience. But how did we come up with that product, and how did we make the original decision on what was the proper replacement?

There’s a lot of science that goes into light, color, quality, and each light had it’s own characteristics. For example, it takes less LED to replace High Pressure Sodium than it takes to replace Metal Halide. And we are talking a lot more than just lumens. We are talking about color temperature, quality of light and something called photopic / scotopic lumens.

In the world of lighting, we measure foot candles with a light meter, this is called a photopic measurement. The light meter picks up everything, including spectrum’s that are invisible to us. Now, we humans see things to, and this is called scotopic lumens. Our rods and cones read and interpret light. And it does so differently than what a light meter does. So it is not uncommon when we demo a LED Light against a HPS light or Metal Halide, we first ask “Which is brighter” before we show the light meter reading. It leaves a few people scratching their heads. Well, that’s the science of of it all, and fortunately there is some handy tables called SP ratios that allow us to take the lumens of a particular light (photopic lumens) and multiply it by the S/P ratio to get the scotopic lumens equivalent.

For example, the S/P ratio for High Pressure Sodium is 0.40. The S/P ratio for LED at 5000K is 1.8. So if you take 40,000 lumens of HPS and multiply it 0.4, the effective scotopic lumens is 16,000. To get the same amount of lumens from LED, take the 16,000 and divide it by the S/P ratio and you get 8888 lumens. So the 8888 lumens of LED is the photopic measurement, the 16,000 LED lumens is the scotopic lumens measurement. So in an nutshell, you need 8,888 lumens of LED to replace 40,000 lumens of HPS from a scotopic point of view.

Here is a handy chart of common lights and ratios for you to use.

There are some home repairs you don’t want to tackle. Here are several red flags to look for when you’re buying a home.

common plumbing problems. Water damage is the homeowner’s mortal enemy. Water causes foundation problems, rot and mold. Want to move into that mess? Probably not.

To see if your potential purchase has suffered the consequences of water damage, start outside and

When you see water damage near an electrical outlet or a light fixture, you may have stumbled onto a fire risk. But outlets aren’t the only place to look for potential electrical problems.

Look for flickering and blinking, which signals a poor connection somewhere along the circuit. Check to see if both halves of electrical outlets are functioning. Make sure bathrooms, kitchens, garages and outdoors have professional electrician should determine whether the home’s circuits or fuses provide adequate power and service. The electrician can look for burned wiring, improper connections, dead-end wiring or ungrounded switches and outlets.

Your home inspector is a font of knowledge! Have the inspector check the air quality of the home to see if any mold spores are present — if water leakage or other common plumbing problems have been an issue, mold may be, too.

The inspector can ensure that the heating and cooling systems are properly installed. The inspector can also determine how old the HVAC system is and ensure that its been maintained

Your inspector will also determine the type of pipe that supplies water to the house—old lead and galvanized steel pipes are going to need replacing.

If the house you’re considering fails these tests, it may be best to move onto the next. If you still think it’s the right house for you, despite the presence of common plumbing problems or the need for an electrical overhaul, negotiate a lower price or ask the seller to pay for needed fixes.

Questions? Thoughts? Leave a note in the Comments section orschedule service today.

Many of the calls that we receive at ElectricMan Inc. are for lighting fixture and ceiling fan installation or repair. Whether you have been working on a weekend project that you just can’t seem to get right, or if you are just looking to update your homes fixtures, Dallas Electrician, ElectricMan Inc. is happy to help with any electrical project you have, but if you plan to do a ceiling fan installation yourself, here are some great tips!

About ElectricMan Inc.

Dallas Electrician, ElectricMan, Inc. has more than 27 years of experience in residential and commercial electrical work and is a family owned and operated business that puts family first. ElectricMan’s motto is “Quality Electrical Services”. We achieve this through our employees. Our professional, licensed, experienced technicians are here to serve your electrical service and repair needs. For more information, please visit our website atwww.electricmaninc.com.