Issue #106
October 2010

Visit Home Energy

Table of Contents

What is the Power Panel Profiler?

One Stop Shop Update

Heat Pump Water Heaters May Save Energy

Ten Energy Saving Tips

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What is the Power Panel Profiler?
When I mentioned the name "Power Panel Profiler" to my wife her first comment was, "Sounds like a new kind of ladies' support under-garment." Under-garment it is not, but it will support your efforts to organize energy measurements for every device your home. Basically, the Power Panel Profiler is a MS Excel worksheet that profiles up to ten individual loads for every circuit in a typical 200 amp, 40 breaker panel found in most homes. That's a total of 400 devices.

The idea here is to provide a simple method to organize the amount of energy used by every device in your home regardless of how you measure it. Net metering techniques can be used on a whole house energy monitor to provide power readings for larger 240 volt loads. These same loads could also be measured with a clamp-on meter that captures current, voltage and power factor readings. Either way, the Profiler will accept the data and calculate energy usage and cost.

Likewise, data from a 120 volt plug-in meter measuring living room lamps or kitchen counter top appliances can be entered as well.

One of the key elements to producing a good energy usage profile for your home is to make an accurate measurement of how long a device runs each day. Remember, energy is nothing more than power times time. In other words, kilowatts of power become kilowatt-hours of energy once time is applied. The Profiler provides an entry for run time per day by device. This may only be 5 minutes for the kitchen toaster or 5 hours for the kitchen lights.

Lights and toasters may be easy to estimate, but how does one get run time for an appliance like the refrigerator or freezer that cycles on and off? Nobody has the time to sit around with a stop watch all day.

Simple - measure using your plug-in meter for a predetermined amount of time such as 24 hours. Note the power in watts when the device is running.

After 24 hours, note the amount of energy used in kilowatt-hours. Multiply the kilowatt-hours by 1000 and divide the product by the power in watts. The result will be run time hours for the 24 hour period or whatever period you ran the test. Running the test for longer periods provides a more accurate daily average.

Larger 240 volt cyclical loads such as an air conditioner or hot water heater are a little trickier to measure as 120 volt plug-in meters are not designed to work with these circuits. If the load is simply on and off, load profiling software can isolate the load from its on-off load level signature and record the energy used.

For loads that are stepped such as an air conditioner and air handler fan that do not turn on and off simultaneously, sub-metering with an extra channel on your whole house energy monitor works better.

Use your electric bill to determine your average cost per kilowatt-hour and enter it into the Profiler. Monthly customer charges and taxes can be entered separately or just rolled up into the overall average cost per kilowatt-hour.

The worksheet is organized around the main panel which is supported by five worksheets detailing eight circuits each. Instructions are included with the download or can be viewed here.

We offer the Profiler as a free download when you subscribe to this newsletter. Sign up in the right column of most any page on the site.

The goal of the Profiler is to help you establish an accurate energy usage base line for your home. When you are planning new energy saving ideas or adding devices, update a copy of the Profiler and compare it to your baseline to determine your energy savings.

One Stop Shop Update
Two months ago the Meter Messenger announced the opening of the One Stop Shop. Today we are putting the finishing touches a variety of different store fronts. Each of these store fronts offer products related to a specific page or section of Home Energy

The first page of each store front offers products that we have hand picked from a myriad of vendors. These products are selected according to quality, price and how well they support related content on the site. Subsequent pages select products from chosen vendors according to the keywords associated with the products on the first page.

This system allows us to offer hundreds and hundreds of products that are maintained by our vendors on their sites. These product listings are dynamic as new products are updated automatically but remain filtered according to specific key words. If you wish to sort by a different keyword, simply enter it in the Find Product... box. Click on Restore Orig. to return to our recommended products page. This whole approach keeps things fresh and up to date without the clutter.

Our website business model is set up to capture a small commission from the sale of any of these products purchased. It does not change the cost to you whether you purchase through the One Stop Shop or purchase directly from the vendor. However, we do hope you will stick with us. Regulations and good Web etiquette require us to disclose the type of business relationship we have with our vendors. Further information can be found on our pricing disclaimer page.

Here's a listing of each store front and a brief description of what it offers:

1. Energy Monitors - Energy Detective, eGauge, Blue Line Innovations and Cent-A-Meter are available. More are in the works so check back often.

2. Plug-In Meters - The popular, low cost, Kill-A-Watt meters are featured along with the Watt's Up product line and others.

3. Power Strips - Power strip timers and smart switching strips are featured.

4. Programmable Thermostats - 5-day, 5+2 day and 7-day models are featured along with a few remote and IP controlled units.

5. Incandescent Lighting Comparison - Bulbs of every type are available including halogen, CFL, LED and more.

6. Micro Hydro Library - Since micro-hydro system products are mostly limited to custom designs and installations we have assembled a great list of books to help expand your knowledge on the subject.

7. Hot Water Heating Systems Point-of use instant hot water system hardware, heat pump water heaters and insulated tank jackets are offered.

8. Wind Energy Books An informative collection of books about wind energy and wind turbine design are offered.

Heat Pump Water Heaters May Save Energy
Electric water heaters are generally the second largest power user in the home behind the heating, ventilating and air conditioning (HVAC) system. In the past, home owners have wrapped their hot water tank with an insulation blanket and/or used a timer to shut it off at night. Other than good conservation practices these two options have been about all you can do to reduce hot water energy consumption - until now.

Recent improvements in heat pump technology are allowing manufacturers to produce water heaters that use the same refrigeration technology that heats and cools your house. Since heat pumps move heat rather than generate it they can cut annual hot water energy costs nearly in half. The drawback is that they are expensive costing two to three times as much as a conventional resistive water heater.

There are two types of heat pump water heaters. The integrated model replaces the entire resistive hot water tank with a new unit that has a built in heat pump. The add-on version adds a heat pump to an existing water heater tank. Both units maintain a back-up resistive heating coil to meet demand, especially in colder weather.

The heat pump absorbs heat from the surrounding air by circulating a refrigerant through an evaporator coil. The refrigerant passes through a compressor and into the tank where it releases the heat absorbed from the air. The cooler refrigerant exits the tank and circulates back through the evaporator coil and starts the heat absorption process all over again.

Cool air is released from the evaporator coil as the heat from the outside air is absorbed. This cool air can be circulated through ducting for supplemental home cooling or be used to keep the garage a few degrees cooler if that is where the unit is located. Due to this air exchange process heat pump water heaters need to be in a room that is at least 100 square feet (10' x 10') to work properly.

Another consideration is noise as the compressor and evaporator fan motor will cycle on and off continuously. This noise will be similar to that of an outdoor air conditioning condenser unit but slightly less due to its smaller size.

Heat pump water heaters are most efficient in warm, damp climates such as Florida or the Gulf states where adequate heat resides in the ambient air throughout most of the year. Residents in cooler states will find the water heater's back-up resistive coil will come on frequently during the colder months negating much of the energy savings the heat pump provides.

For more information on heat pump water heaters please visit the Heat Pump Water Heaters page of Home Energy

Ten Energy Saving Tips
1. If you have outdoor security lighting use a motion sensor to extend bulb life and save energy.

2. Use timers on decorative outdoor lighting as we move into the shorter days and longer nights of the year. This is especially true for holiday lighting.

3. Try not to switch energy efficient bulbs such as CFL's on and off too frequently as it shortens bulb life.

4. If you use a heat pump with supplemental heat strips, step your programmable thermostat settings in two degree increments every 30 minutes when warming the house from overnight setbacks. A step of three degrees or more will usually trigger auxiliary heat to come on. Auxiliary heat strips do not have to run long to wipe out all the energy savings gained by lowering the thermostat the night before.

5. Be sure to check for leaks and good insulation coverage on duct work in your attic, crawl space or basement. If water pipes reside near duct work in unconditioned space, you may want to add an electric heating tape to those pipes to prevent freezing. Insulating duct work will lower the temperature of any unconditioned space it travels through during the winter months.

6. If you use natural gas, propane or fuel oil for heat, it is a good idea to install a carbon-monoxide detector in your home to alert you of a combustion or ventilation problem with your furnace.

7. Keep your south facing windows clean this winter to maximize solar heat gain. Move objects to allow sunlight to heat tile or concrete floors where ever possible.

8. If you use a fair amount of hot water in your home consider a drain water heat recovery system. Heat from warm waste water flowing down the drain line is recovered and used to assist the hot water heater. Click here to learn more.

9. Boost air flow in rooms that are often too cold in winter and too warm in summer with an air grille booster fan.

10. Check the website to learn about your eligibility for tax credits pertaining to energy efficient appliances and equipment installed before the end of the year.

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