Friday, April 15, 2011

LED Lighting Becoming Mainstream

With prices approaching affordable, LED lighting is finally becoming mainstream.

Recently, we’ve tested 3 different brands of 5-6 watt, LED MR16 lamps. They range in price from $12 to $20 each, and have a life span of 20,000-30,000 hours. We’ve done the math, and if used about 40 hours/week, this can be well over a decade of illumination.

In comparison to the LED options, MR16 halogen bulbs (20 and 35 watt) cost around $5 each. They last about 5000 hours (if you are lucky), and have around 250-300 lumens. In our office environment, the LED bulbs appear slightly brighter than the 20 watt 250 lumen halogen lamps.

Beyond brightness, if the color of light is a concern, the LED’s are available in 3000k (Kelvin degree) warm white or cool white options. Typically, lower k temps mean a warmer color of light. But we found while halogen bulbs can be anywhere between 2800k to 3200k, they do appear slightly warmer than the LED’s in color, no matter the source.

There are two main factors to consider when comparing LED, halogen, xenon, or fluorescent options: 1. Duration of use; 2. Cost of replacement. The question is how long will the lights be on each day? The more they are used, the quicker the payback in energy savings. You can expect an LED lamp to last 4-6 times as long as a halogen. Keep in mind that while the purchase price of an LED bulb might be 3 times that of a halogen, an LED lamp can boast over $100 in savings over its 50,000 hour lifespan. When you add to these factors the cost and trouble of going to the store, finding the right bulbs, and replacing them; the decision in favor of the LED bulb seems fairly simple.

But other options, such as undercabinet lighting or recessed lighting could introduce variables that would sway your preference. This winter, thinking about efficiency and life span, I purchased LED undercabinet lighting from a MABA member (previously, I had used Xenon lights but was disappointed by the inordinate number of bulbs that quickly burned out). The reflective nature of the countertops created an unexpected consequence. Polished granite, it turns out, reflected the individual dots of light. Therefore, florescent T5 undercabinet lighting, due to cost and energy use (and the fact that it does not reflect off the granite) turned out to be a winning product for this application.

Compact florescent bulbs in recessed can lights are a viable option depending on your usage. LED’s currently win out in life span and energy savings, but when adding the extra cost of trim rings, and taking into account how often you use the lights, they may not be optimal for every situation. However, if you want to be able to dim the lights, the LED’s are the way to go.

Candelabra-base bulbs are another challenge, but we have tested a couple of products from former MABA member EFI (Energy Federation, Inc.) as well as The Home Depot with pleasing results. While not dimmable, there are some 5, 7 and 9 watt CFL’s that provide great lumens with a color similar to that of a traditional incandescent light.

For more product details, please follow the links below.

EFI candelabra base, 40 lumen/watt rating, with the flame-tip decorative style:

Home Depot Product comparison:

Home Depot - highest lumens and least expensive:

These are the 3 MR16 LED's that we've found:

This is the brightest lamp we tried:

Most efficient, least expensive, and bright:

Tuesday, April 5, 2011

Demystifying Energy Improvements

If you look out your window in the morning and see this on the neighbor’s roof, you know something is not quite up to par with their home’s energy efficiency.

Besides causing you to wonder if your own roof has tell-tale spots (you may want to put on your robe and take a look while the frost is still on the roof, or better yet, ask your neighbor what they can see over their morning cup of coffee), signs like these reveal the lack of knowledge that homeowners, and even many builders, have in regards to performance expectations.

The dark spots on the left side of this picture reveal areas where heat from inside the house has escaped to melt the frost off the shingles. This is concerning for three reasons. The first is the potential of ice damming and the resulting damage. The second is the transfer of heat to the outdoors, which reduces efficiency and increases utility bills. The third, and possibly most concerning, is the evidence that for this home, energy efficiency may have been an afterthought, and along with the keys, the homeowners may have purchased an abundance of missed opportunities and unrealized potential savings.

Last week, I (Cara) crawled into an attic with Anthony as he taught some local maintenance technicians how to make their apartments more efficient. Going into the project, I thought I knew a fair amount about building with efficiency in mind. What I learned, however, is unless efficiency is a priority of the builder, it simply does not exist. The spots on the roof should not be there. They are easily preventable, and planning their prevention, or in this case, their correction, is essential to a well performing structure.

Over the next few weeks, we will work to demystify energy efficiency. We will describe what the term means, the modern expectations for an energy efficient home, and how these expectations are realized.

Watch our upcoming blogs for hints on how to make your home more efficient, including a list of projects, some approximate costs, what improvements can give you the most bang for your buck, and advice on what you may or may not want to tackle on your own.