When doing home energy audits I have not been recommending the use of LED lights due to cost. However we recently installed the first of what will be many LED light bulbs in our home, and after running some numbers it seems the price has dropped to the point that they are competitive with CFL lights. Yes, they are more expensive than a CFL bulb, and much more expensive than a standard incandescent bulb. However the way you need to look at is you are purchasing your light bulbs for the next 10 years with the purchase of one LED light. If you take a look at the chart below, you can see based on costs I saw at my local Home Depot store, there is a good energy and monetary savings over the life of the LED bulb when you take into consideration how many times you would have to replace the other bulb types. The savings is even greater in a commercial facility where you are paying someone to change out those bulbs.
Now it appears that with an electricity cost of $0.11 per kWh that if you can find a LED light for $15.50 or less, you will save money over a CFL through the life of the bulb.
Why not look into it yourself with this little calculator (here), just input the costs of the light bulbs you find at your local store along with their rated wattage and your local electric costs and see how much you can save.
Now this little light bulb exercise holds true with any upgrades in efficiency whether you are replacing light bulbs, a furnace and air conditioning unit, to making envelope upgrades to a new home or addition. You pay a little more now for efficiency, but in the overall life of the project you end up saving money.
I am sure we have all seen graphics like these, giving us a pretty picture of what is one of the primary contributors to climate change, as buildings contributed nearly half of all the CO2 emissions in the united states in 2010. Not to mention it gives us an idea of what kind of pace we are using our fuel sources, and as they become more difficult to obtain, costs will just continue to rise. Energy usage in our homes is becoming a big deal as energy codes are becoming stricter and utility companies are being required to produce a certain percentage of their product by renewable sources and provide energy efficiency programs for their customers.
Related to home energy usage, I have noticed a lot of press on Net Zero Energy Homes and even attended a webinar by Matt Grocof who renovated a home built in 1901 and is now the oldest home on record to be a Net Zero Energy home. Now most Net Zero homes are new homes as it is easier to build new rather than retrofit energy efficient systems into an existing home, hence the reason for my attendance on the webinar. With more than half of the 113.6 Million homes in the United States, over half this number was built before 1980. This leads to a huge potential of improvement in energy usage with our existing housing stock and that is why organizations like the Affordable Comfort Institute (ACI) have created the 1000 Home Challenge to create case studies of how to drastically bring the usage of our existing housing stock. Therefore I was hoping to learn more about some of the retrofit strategies that were used to obtain net zero.
Not everything about green or sustainable homes is sexy. The majority of what makes a structure green or sustainable you don’t even see. That is the case for the first big project we tackled after we purchased the home in 2005. We decided to first air seal and insulate our attic because the existing levels when we bought the home were anywhere from 0”-4” of blown fiberglass which is an insulating value of R0-10. Now back in the 60’s when the house was build and energy was cheap this was an acceptable level, however not by today’s standards. Now after working in the field performing home comprehensive home energy audits for a little over two years I understand the majority of homeowners do not know this or fully understand what it’s purpose is and how it works. They just know their bills are high and they are not comfortable. And as a young door to door sales girl asked me one time, “How many inches of insulation do you have in the attic”. Which to my surprise, many people do not know the answer to that question, and of course for the professionals reading, the answer in part is it depends on the type of insulation that is up there that determines the overall thickness that should be in the attic. So the general rule of thumb in the attic is if you can see the ceiling framing, then you don’t have enough insulation. Now since my wife and I are in the design and construction industry we knew at the time we started the projects, buildings we were designing required and R-30 for attic insulation. So we did not have to have a home energy audit performed on the home to know by adding insulation to the attic we would save money on our heating and cooling bills. So our decision was to install an additional R49 to bring the overall insulation levels up to an R55.
By the numbers:
Adding R-19 expected to save – $346 yr
Additional R-30 expected to save – $93 yr
Total estimated yearly savings of – $439yr
Savings estimated utilizing REM/Design
Now insulating the attic was a two year process, as the decision was to split it up into 2 phases by air sealing and installing a layer of 6” R19 fiberglass blanket insulation in-between the ceiling framing in phase 1. Then with the energy savings from that project, it helped offset the cost to purchase and install an additional insulation layer of R30 running perpendicular to the first layer.
Therefore, a couple of years ago now I wrote an article stating my interest in participating in the 1000 Home Challenge to use my home as a case study to find strategies to reduce an existing homes energy usage by 70-90%. In August of 2012 my home was accepted into the program. Why the 1000 Home Challenge instead of a program like LEED for Homes? At the time that my wife and I began the journey of “greening” our 1965 ranch home the LEED program did not make it easy to certify an existing home without completely gutting the home and that was never our intention. Sym-Homes’ mission was to show homeowners affordable strategies to make their home more energy efficient. As not everyone can afford, or is up to the work that is involved with taking the exterior walls down to the bare studs. Also the LEED for Homes and other energy efficiency programs are a onetime test and certification that is based off of energy modeling and tests/inspections of installed measures. With the Thousand Home Challenge there will be a one year monitoring period of the utility bills to verify that improvements are performing as expected and that the homes overall energy usage is meeting the set targets.
I recently read an article (here) from Dr. Joseph Lstiburek. It wasn’t his overly technical type of writing diving deep into building science, it was more of his personal story of how he began his career and some of the great building science minds of the 60’s & 70’s that he had the pleasure of meeting and learning from. Yes I did write the 60’s & 70’s. Building Science is not a new thing, the topics Joe has been presenting have been done before, but no one was doing it and to this day building science is still a mystery to most of the design and construction industry.
Now what I took from that article is not the name dropping of who he met early in his career, but more of what he did with those connections and new found knowledge. He applied it, he took what he learned from those individuals and put it into his then home building practice. And to this day he is still refining some of those early construction practices.Read the rest of this entry »