Energy Vampires: Ways to Reduce Energy Consumption Around the House

June 17, 2011

Energy Phantoms or Vampires account for approximately 5% of the electrical energy used in every household, spread that across every home in the US and it adds ups up to 65 billion kilowatt-hours of wasted electricity each year.

As quoted from the Investigations of Leaky Electricity in the USA  paper ….. the average US house leaks constantly about 50 Watts. This is approximately five percent of the residential electricity use in the US. Leaking electricity falls into three major categories: video, audio and communication. Video equipment such as TVs, VCRs, cable boxes and satellite earth stations account for the largest share of residential leaking electricity, approximately 35%. Audio equipment accounts for 25% of standby consumption, and communication devices (answering machines, cordless phones and fax machines) are responsible for an additional 10%.

Energy vampires  can be defined as electrical devices that consume an amount of energy by doing nothing but waiting to be activated or used. This standby mode can be most recognizable in TV’s, video and audio equipment. But it really goes way beyond that.

Some of the common energy wasters in most homes are the adapters (aka: wall warts) that come with rechargeable battery-powered cordless phones, cell phones, digital cameras. You will also find them with many music players, power tools, and other electronic devices.

Conceptually, if you can just unplug all of  them when not in use, this would solve much of the problem. Easier said than done. Being the techno geek that I am, there will always be a another way.

Techno Solutions:

  1. Individual Timers: You can use traditional electrical timers or this new style like this Belkin unit. It is designed specifically for applications that only need to be on for a certain amount of time where the specific time of the day is not important. At $10 bucks, it might be a good solution for your clothes iron, electric tooth-brush or MP3 player.
  2. Group Timers: Combined with a surge protector, these devices will not only protect the equipment connected, but also shut them down to cut off the phantom load. Price wise, they are still in the same range as a regular surge protector/power strip. Additionally, many of them include a couple of priority plugs that stay energized all the time.
  3. X10 Technology:  If you read my article on X10 Technology, you may  have already figured this out. Combined with your X10 units and the software package, you can set timed events for all of these devices. Or combine one with a power strip. If its possible; try to cluster all of these type devices into groups. Plug all of them into a  power strip, then plug the power strip into the X10 timer. Schedule the timer to run only a certain amount of hours per day. Probably 3-5 hours max.  For devices like televisions, DVR’s and audio equipment; try to do the same thing. If you dont use X10 timers, any traditional timer will work as well.   (TIP: If you have a cable box, U-Verse or satellite receiver, it would be best, not to cycle this device on and off. It is very normal for the service providers to perform late night downloads to update your software, turning them off at night may be problematic and cause you to have some service interruptions or cause you to miss some updates.)
  4. Energy Star Equipment: As part of the design specification, most energy star devices do a good job in reducing the phantom loads. However, because devices like televisions, microwaves and DVR’s usually have clocks in them, they will still use a little bit of energy. If you choose to shut these devices down, just understand that the device might require you to re-set the clock every time. The only way to find out, is to try it.

Managing Other Electric Devices: Here are a few tips for keeping the energy usage in check on the non-techy type equipment:

  1. Refrigerators: This device can use as much as 20% of your total consumed AC energy.   Most new refrigerators with electronic thermostats come preprogrammed to run 0F and 40F (freezer/refrigerator). If you have an older style, use a thermometer to make the adjustment. Set the freezer between 0-3F. TIP: Energy Star rated  refrigerators will make a significant impact on your energy usage.
  2. Clothes Dryers: Use the cold or warm cycle s as much as you can. Avoid the hot cycle.
  3. Dishwasher: Always run it full. Dry them cool instead of hot. Drying cool does not impact the dishwashers ability to sanitize the dishes. However, you may have to wipe them off before you store them. Doing this will reduce the dishwasher energy used by 20%.
  4.  Water Heater Thermostats: The default setting for water heaters is 140F, 120 will work in most cases. If you live in the southern part of the US, it is easy to drop the temperature during the summer. You will never notice the difference.
  5. Set Back Thermostat: Even though this does not technically fit into this article, it is a pivotal element in energy reduction. Worth an article on its own!!
  6. Energy Star Rating: Look here first when replacing appliances. These subtle changes will make positive affect on your overall energy usage

The Gas Gauge (Geek Overload): Believe it or not; studies show that if we are able to monitor the amount of usage of a product (while in use) it will cause us to use less. There are multiple devices on the market today; such as TED, Power Cost Monitor, and Energy Monitor that will provide instant feed back on energy usage. You will be able to see all the energy vampires at any time of the day. Some of them have software with data loging history, peak demand and the list goes on. Its pretty cool (geeky) to walk around the house and start yanking plugs and watching the meter drop. (NOTE: The devices mentioned may require  installation, in some cases they only work with certain brand of meters. Read the webpages carefully before purchasing).

Google Power Meter: In their “save the world mentality” Goggle has teamed with some utilitiy and equipment providers to allow you to view your usage on line. Neat idea and its free, but has limited availability.

TOP Household Electricity Vampires (Courtesy of Lawrence Berkley Laboratory)

Appliance Saturation Watts Watts / House
TV 180% 6 10.8
Cable boxes 50% 20 10.0
VCR 80% 10 8.0
Compact audio 67% 10 6.7
Answering machines 60% 5 3.0
Alarms 19% 15 2.9
Video games 55% 5 2.8
Portable stereos 65% 3 2.0
Rechargeable vacuum 20% 5 1.0
Cordless phones 49% 2 1.0
Fax 4% 15 0.6
Satellite 5% 11 0.6
Toothbrush 13% 3 0.4
Smoke detectors 84% 0.4 0.3
TOTAL 50.0

So what is this in dollars and cents. For example; if you use 1000kW per month at .12 per kW, that works out to be about $6 bucks a month. (1000X.12)*.05=6. Unless you are prepared to take some drastic measures, you may be lucky to cut 50 to 60% of that number. So look for $3-5 per 1000kW used as a target.

Okay, this article might be a little anal, to gain back $6 bucks a month as a payback period is not worth recognizing. However; look at it like a leaky faucet. Its not a bad idea, and long term its will save you a couple of bucks and if everyone did it we would have less dependency on the grid.

Advertisements

Radiant Barrier – Things to Consider

April 24, 2010

Radiant Barrier has a long successful history as a way to reduce heat loads, but didn’t really get the deserved credit until NASA  acknowledged its use in the Space Program.  As a construction product; it is basically heavy-duty aluminum foil with at least one shiny side. For a greater understanding of the principles of this product, see  How it works? 

During the summer, an attic radiant barrier, combined with existing R-19 attic insulation, may reduce heat gain through the ceiling from 16%-42%. For single-story houses, typically about 15%-25% of the summer cooling load is due to ceiling heat gain. During the summer, the interior ceiling becomes a radiant heater adding heat to the interior spaces. The heat gain reduction from a radiant barrier installation will usually result in a total cooling load savings of 2%-10%-possibly as high as 15% in attics insulated to R-11 or less. Higher savings occur when retrofitting less efficient buildings. Buildings with little to no attic insulation and a high volume of attic ventilation typically provide the most dramatic energy savings from a radiant barrier. The hotter and sunnier the climate is, the more beneficial the radiant barrier installation becomes.

Types of Radiant Barriers

  • Foil Faced Decking Material: With the trade name of TechShield, this radiant barrier product is applied to the back of roof decking during manufacturing and can be applied when the house is built or during a re-roof. Efficiencies of this product is in the neighborhood of 95-97%
  • Rolls or Sheets: The sheets can be applied in a couple of methods; 1) Tacked up on the rafters or 2)rolled out on the attic floor. The labor makes these choices fairly expensive, but you can reduce the installed cost by making it a  DIY project.
  • Spray on Solution:  This is a fairly new option, and came about because of the installed cost  of rolls or sheets. However, spray on radiant barrier is only about 65% as efficient as the aluminum foil types and lacks the low emissivity factor found in the other products. So it may have a lower installed cost, but your benefits will not compare to previously mentioned type.

Things to consider before purchasing or installing a Radiant Barrier

  1. Climate: If living without air conditioning is not an option for you,  you may live in a temperature zone worthy of installing radiant barrier. Studies have shown, this product works better in very hot climates. If your attic regularly exceeds 130 to 140 degrees F, radiant barrier can reduce the attic heat load allowing your HVAC to work more efficiently , in-turn reducing your electricity consumption. If you live in climates similar to Arizona, Florida, or Texas,  you are probably a candidate for radiant barrier.
  2. New Construction or Re-roofing plans: If you are considering either of these projects, foil faced roof decking can be purchased for a couple of dollars per sheet. This is the most inexpensive method to obtain radiant barrier. 
  3. Attic Insulation: Make sure you have enough attic insulation, radiant barrier is not an insulation replacement product but just part of the equation. Having the proper amount of attic insulation combined with a radiant barrier product will provide the maximum benefit.  Also see Insulation: Do you have enough? and Insulation Choices.
  4. Radiant barrier as a DIY project: Choose a product that has high tensile strength or is embedded with tightly woven fiber mesh; either of these features will reduce the opportunity for the product tear during the installation process. There is also a bubble pack version that appears to be as strong too. The bubble pack version is a great product for re-insulating HVAC ducts. Any radiant barrier product should be UL listed and/or have a NFPA “Class A”  flammability rating.
  5. Location to place the radiant barrier: The following table shows a comparison of the effectiveness of the product applied in 4 different locations. Even though the attic floor application appears to be the most effective, this location may 1) cause moisture to collect under the barrier, 2) collect excessive dust; known to reduce its effectiveness and 3) add to the complexity to performing future work in the attic.  HomeownerBOB recommends avoiding using this product on the attic floor. 
Radiant Barrier Location Whole House Tests Test Cell Tests
Mineral InsulationLab Oak Ridge Lab Solar Energy Cntr Tenn. Valley Auth.
Roof: attached to roof deck —- —- 36 – 42% 16%
Roof: stapled between rafters —- —- 38 – 43% —-
Roof: stapled under rafters 24% 25 – 30% —- 23 – 30%
Attic Floor*** 35% 32 – 35% 38 – 44% 40 -42%

If re-roofing is not in your future, installing the barrier on or under the rafters to gain the most long-term effectiveness is probably your best choice. Most of these products qualify as an energy tax credit so take advantage of the opportunity and get it installed before it gets too hot.

Reference Studys of Effectiveness of Radiant Barriers

  1. TAMU Study
  2. Radiant Barrier Fact Sheet; DOE Oak Ridge National  Laboratory