January 4, 2011 by: Eric Mac Inerney

My wife and I are designing and building a new energy-efficient home. We are working very hard with our builder, Risinger Homes, to achieve a 5-star (highest) rating in the Austin Green Building Residential Program.  One major focus is how to make the lighting more efficient. In a future post, I will discuss some of the technical basics of lighting.  I've designed lighting for our churches and residential clients for years, but I've discovered a lot just by testing some of the available fixtures.

Like many contemporary residences, most of the general lighting in the new house will be recessed cans.  Typically, these fixtures have used standard everyday incandescent bulbs, which provide a very warm diffuse light, good color rendering, and excellent dimming. Dimming is really important to our family, as we regularly change the light levels in the room to suit the activities.  For example, when the kids wake up, we try to increase the lighting level slowly to help wake them up without blinding them. Similarly, as they go to bed, we dim the lighting levels to help their circadian rhythms get them to sleep. 

The problem is, incandescent bulbs, which have not changed much since Thomas Edison worked with them in the late 1800s, are not very energy efficient.  Much of the electricity used by an incandescent bulb is given off as heat rather than light.  This is doubly bad in a warm climate like ours, because not only is the energy wasted, but also you then have to use additional energy with an air conditioner to remove the added heat.  Incandescent lights also have relatively short (1000-2000 hours or so) life-spans.  This means they have to be replaced more often which increases the waste and increases the number of times I have to get the ladder to replace them.

Up until recently, the main alternative for incandescent bulbs in recessed cans has been compact fluorescent lamps.  We have used these for years commercially, but my wife (like many people) is not overly fond of the light quality or the color temperature of the fluorescents—though there has been tremendous improvement in the fluorescent technology over the last decade.  An additional problem is that dimming compact fluorescent lamps tend to be expensive and/or not work well.  

The development of LED lighting has brought an exciting new solution. About a year ago, I tested an LED screw-in bulb I purchased at Home Depot.  The lamp did not dim, and had such a hot spot that I returned it that day.  Since then, things have changed dramatically and many companies are producing LED lamps or fixtures that can be put into a standard 6” incandescent recessed housing (think of the millions upon millions of existing light fixtures that are out there and you can understand why thy are pouring so much money into this).  The advantage of these new LEDs is that you can now get the lighting levels you need efficiently, with good color temperature and color rendering, and dimming the lamps using standard dimmers.  These fixtures can easily be retrofitted in to existing cans (well, it does take some work, my installation skills only got them in halfway—but I also had to make sure I could get them back out) or incorporated in new construction. I was really excited about the potential and working with one of our lighting representatives, I was able to get a great deal on some of the newest products.

I was all set to order the 50+ cans we need, and though I had brought a sample home previously, I thought I would do one last check family since my family would be living with these lights for a long time.  I got the sample back and actually installed it (mostly) in one of the recessed cans in the duplex we are renting while the new house is under construction.  The result was negative. My wife did not feel comfortable with the color temperature and quality of the LED can—especially with incandescent sources next to it.  The LED we were looking at was a 3000K color temperature with good color rendering.  It has a nice white light when you play with the sample and it dimmed beautifully, but once installed, we realized that the color quality was not at all what we were looking for at all.  Interestingly, the white light dimmed to a grey color.  Whereas this light would be fine for an office, my wife is very sensitive to light level and quality and really wanted the look and feel of incandescent lighting.  Scrambling, I contacted a number of vendors and was able to find a number of similar products that came in 2700K, which is close to the color of incandescent sources.

Within a couple of days I had all four cans in the living room replaced with two 2700K LEDs and two 3000K LEDs.  Though on paper the lights are similar, the difference between the four was astounding.  The two 2700K LEDs gave a much better and warmer light.  Right now we have four test models installed.  Here is a short video we shot showing the lights.

Cree LR6 2700K
This light had great distribution, great color rendering and good color temperature with a slightly pinker tone.  Looking at the fixture, I am not totally sold on the trim, but it does seem to help distribute the light evenly.  The Cree unit (and the Lithonia and Halo units) has a lens that covers the LEDs and diffuses the individual point sources, which I found to be nicer.  Manufacturer's website: Cree LR6

Toshiba E-core
This light had great color temperature and color rendering but was dimmer and had much more of a hot spot.  Toshiba is coming out in the next month with their second generation, which will give us more options in brightness, beam angle and color.  Manufacturer's website: Toshiba E-core

Lithonia Reality 6 3000K
This is the original unit I tested.  The light is very white and dims grey.  The units will work fine in many environments; my wife just did not feel comfortable with the color.  They have a 2700K model due out in the summer, which should be very interesting. Manufacturer's website: Lithonia Reality 6

Halo 3000K
Like the Reality 6, these fixtures will work well commercially where the expectation of color temperature is different.  In fact, I can’t wait to use them in our churches.  The Halo also has a nice selection of trims to make the recessed cans look different. They have 2700K model available, and we have ordered one to test. Manufacturer's website: Halo LED

The lamps look like they will cost me between $50 and $80 a piece (retail will be more expensive), plus you need the housing if you are doing new construction ($8-$10).  This is roughly 10 times the cost of a standard incandescent Par 30 flood.  However, the lamps should last some 20-30 times longer, which is a savings in lamps plus many fewer times per fixture that I have to climb a ladder.  Add the fact that LED puts out the same light for 50 watts less power and again that much heat to account for with my AC, and I am sold.  Now I have to decide which one….

This video is a quick demo of the 4 different lamps we installed...

 

Lessons Learned

  1. The technology and pricing have reached a point now where LED is a viable alternative in houses, churches, and offices.
  2. The market is still changing rapidly; what is current today may well be out of date in 6 months.  However, I don’t think that should stop you from adopting the technology. Just make sure you are looking at the most recent offerings when you make your decision.
  3. Though LED’s emit far less heat than incandescent sources, lifespan of the lamps can be greatly diminished if the heat they do generate in not properly handled..  Be sure you are dealing with a reputable manufacturer who is going to properly deal with the heat at the chip.  (You can read more about LED chips in Lighting Technical Information.)
  4. Most of all, until some consistency between manufacturers is achieved, be sure to get a sample of the fixture and install it in a similar environment to make sure you like what you will be getting.  The four we tested (and the one I tested previously) were all quite different, and everyone reacts to the color and quality somewhat differently.

I've written an overview of lighting basics as a great resource for anyone about to make their own lighting decisions.  Click below to download your copy of "Lighting Basics - What You Need To Know."

Lighting Basics

Church Design & Construction/ Residential Design & Construction/ Technology/ Sustainable Design