Monday, October 6, 2014

Cutting Energy Consumption in Your Home

from EIA
For decades, heating and cooling what the U.S. Department of Energy calls space conditioning accounted for more than half of all residential energy consumption. In recent years despite the increasing size of the homes, heating and cooling energy use has fallen to less than 48%. Better insulation and more efficient air conditioners, heaters and heat pumps and a slow migration towards the south have begun to change that. It turns out that it takes less energy to cool a home than keep it warm in the winter and frankly, wearing a fleece jacket and warm socks can make a 66 degree Fahrenheit room comfortable. The most recent Residential Energy Consumption Survey from the Department of Energy’s Energy Information Agency (EIA) show that 48% of energy consumption in U.S. homes in 2009 was for heating and cooling, down from 58% in 1993. Today, according to data collected by the EIA heating accounts for approximately 42% of energy usage, cooling accounts for 6% (despite the increased use of air conditioning throughout the United States), hot water heaters use 18% of all power, refrigeration accounts for 5%, lighting 5% and other appliances and electronics account for 24% of energy use.
from EIA

Over the years I have been making both small and large changes to my home to reduce my energy consumption. I started with the easiest steps; lowering the thermostat in the winter and raising the temperature in summer, purchasing energy star eligible appliances and choosing an LED TV over a plasma or LCD for our new big screen TV. The other simple step was to change the incandescent light bulbs for florescent, LED fixtures in my track lighting and LED replacement bulbs. The first generation of LED bulbs were a bit blue and make the clothes in my closet look oddly colored, but the newest bulbs are a much softer light, more what I like. I’ve also installed solar films on the windows and patio doors and hung lined drapes and curtains on most of the windows. These were small steps, but I learned over the years that small steps do add up.

A few years back, after a particularly cold winter, I turned to the Building Envelop Research of the Oak Ridge National Laboratory for guidance. The Oak Ridge National Laboratory performs their Building Envelop Research for the US Department of Energy, DOE. The DOE publishes their guidance in their “Insulation Fact Sheet,” which is available on the blog home page. Following the recommendations by the Oak Ridge National Laboratory the attic, crawl spaces, eves, ductwork, underside of a large portion of the main level floor were insulated with cellulose. The pipes, wall end caps, knee walls, sump pumps and all identified areas were sealed, the garage ceiling was insulated and an insulated garage door installed. I was actually surprised at the winter energy savings and pleased with the improved comfort in the master bedroom and bath.

When my heat exchanger that heats and cools the upstairs failed, I replaced it with a much more efficient unit (SEER 19), improved my ducting and air flow and installed a “smart” thermostat. The solution to improving my duct air flow was simply to install galvanized steel trunk lines and distribution boxes, properly sealed and insulated. The trunk lines have straight runs and gentle curves to the distribution boxes, but I used flexible R-8 reflective ducts to tie into the last few feet of the vent sleeves (to avoid replacing all the boots) keeping the transition as smooth as possible. I used reflective insulation at a minimum of R-8 to take advantage of what little boost I can get from the decreasing the emittance of the ducts. The result was much better cooling and heating at a lower monthly cost.

Last fall we discovered significant water damage to the front of the house. We ended up removing the imitation stone facing from the front of the house, the house wrap, OSB subsiding and insulation and repairing/replacing the water damaged sections of the sub-structure with pressure treated lumber. Once repairs were made, we installed new R-15 insulation on the main part of the house and added insulation to the garage then use pressure treated plywood to replace subsiding, wrapped all exposed siding with DuPont Tyvek. After carefully flashing all elements, we installed a Driwall Rainscreen system by Keene products and then install the new real stone facing. Hopefully, we will gain some small benefit from the improved and added insulation and have solved the water infiltration problem.

Since I was replacing the front wall of the house, I took the opportunity to run the PVC ducting for a new high efficiency hot water heater and furnace. This past week I upgraded my major gas appliances; the old hot water heater to a new high efficiency gas hot water heater and the gas furnace to a new 96% efficient furnace. I am hoping to trim my energy usage for hot water and heating. Higher energy efficiencies can be achieved with geothermal (ground-source or water-source) heat pumps, and geothermal heat pumps have low operating costs because they take advantage of relatively constant ground or water temperatures. However, the installation even on a new home is expensive because of the need to bury coils to deliver constant temperature fluid or install a groundwater pump and injection well to supply constant temperature water to the system. Ground-source or water-source heat pumps can be used in more extreme climatic conditions than air-source heat pumps, and are more effective at cooling and heating at the extremes, but I found the cost to retrofit my existing home to be prohibitively expensive.

Late in 2009 we snagged a Residential Solar Incentive Rebate and combined that incentive with the federal tax credit of 30% and the hope to sell the solar renewable energy credits, SREC’s, made the big leap to buy a 7 kilowatt solar photovoltaic system that has saved us approximately $1,230 per year on our electric bill. That is about twice the savings we achieved by insulating the house; however, the cost (before rebates and incentives) was more than ten times the cost of the insulation project. Even after all the rebates and incentives this energy savings was many times more expensive than the insulation project and the financial gamble is only working out because I have been able to sell my SRECs in the Washington DC market (I got grandfathered). With a little luck I may reach payback in 7-7.5 years (from installation) and then I would have $1,231 in free electricity each yare for the remaining life of the system and that would be awesome.

According to data from the Energy Star program, over 7% of all household electricity is wasted in phantom loads. Households are buying more and more electronics, but Energy Star equipment has a lower stand by consumption and consumers are becoming more aware of not leaving unnecessary chargers plugged in. Televisions, DVD and DVR’s , video games, computers, tablets, monitors, printers, electronic charges, AC adaptors, microwave ovens, electric coffee pots and toasters –any device that that has a digital display or clock, or a ready light is using power. While I am not unplugging my microwave after every use, I did replace my microwave with an Energy Star unit that draws less standby power and I use the power saving mode on my computer and printer. Like changing your light bulbs, reducing these wasted loads is an easy way to cut your energy consumption even without unplugging everything when you leave the house or go to bed, there are still savings to be had. The Energy Start program has many painless suggestions for how you can cut the wasted energy.

The U.S. Environmental Protection Agency (EPA) is kicking off its first national ENERGY STAR Change the World through Community Service Tour. During the month of October there will be events in Worcester, Mass.; Baltimore, Md.; San Francisco, Calif.; Denver, Colo.; Orange, Calif.; and culminating on “ENERGY STAR Day,” October 28, in Phoenix, AZ where ENERGY STAR where there will be a ribbon-cutting ceremony to celebrate an extensive energy-efficiency upgrade at U.S. Vets, a 135-unit non-profit housing facility for homeless veterans in Phoenix. The renovation included ENERGY STAR­-certified lighting, appliances, insulation, weatherization and windows, plus upgraded HVAC equipment and might have some useful suggestions for all of us.

EPA is hoping the public events will inspire us to consider what we can do to make a difference through energy efficiency, to share their “stories of positive energy,” and take the ENERGY STAR Pledge in celebration of ENERGY STAR Day. EPA is encouraging consumers across the country to join the millions who have already pledged to take action to save energy and money in their homes and protect the planet- all good things.

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