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Energy savings in 3D with CO2

Posted in Energy conservation, Heating and cooling on September 30th, 2015 by Susan – Be the first to comment

PUD Engineer Jim White’s Variable Air Volume box, 3D-printed in plastic at the Department of Energy’s Oak Ridge National Laboratory.

PUD Engineer’s proposal wins national crowdsourcing contest

A breath of fresh air is always nice, but too much of it can result in wasted energy that’s costly to owners of commercial buildings.

A proposal from PUD Engineer Jim White to use carbon dioxide monitors to help control air volume in buildings got the nod from the Oak Ridge National Laboratory, winning the lab’s Buildings Crowdsourcing Community Campaign last month.

Jim White

CO2 sensors will be installed next to 60 thermostats in the PUD’s Headquarters Building in downtown Wenatchee.

White, a Senior Energy Efficiency Engineer with a PhD in mechanical engineering, won in the Sensors and Controls category for his design for variable air volume (VAV) mixing boxes. His design combines temperature and carbon dioxide sensors to control outside airflow settings of individual VAV boxes. It could yield significant energy savings while improving air quality.

A model of the concept was 3-D printed and exhibited at the lab’s Industry Day on September 24.

‘A kid in a candy store’

White said he felt like “a kid in a candy store” at the conference, which featured displays and demonstrations of scientific advances. For example, White said he watched a clothes dryer technology that uses ultra-high frequency sound vaporize water from clothing in seconds. This could be used to quickly dry clothes at the end of a wash cycle, eliminating the need for a separate dryer.

Now that’s something we can relate to.

Unless you’re a building scientist or operator, White’s innovation seems a little more obscure. But it has the potential to reduce energy use in buildings significantly.

White’s idea will be put to the test at the PUD’s Headquarters Building this winter, where he expects to cut energy consumption by 20 percent. That’s in addition to a 35 percent drop in energy use from earlier improvements made at the office building on Wenatchee Avenue.

CO2 sensor

The monitor on the left shows carbon dioxide levels in a room, while the chart on the right indicates whether a room is adequately ventilated.

How does the carbon dioxide theory work?

Humans emit carbon dioxide as they exhale, White explained. Carbon dioxide sensors can be used to indicate how much ventilation is needed for any given space. Instead of setting air flow at a fixed position, which can cause the space to be over air-conditioned, CO2 sensors can be used to vary the volume of air based on actual ventilation requirements – what those in the room need to be comfortable and refreshed.

Keeping your cool

Tying air flow to carbon dioxide should eliminate over-ventilation and excessive cooling, which wastes energy. “This will still give the ventilation that’s needed, but allow for optimum levels,” White said.

Demand Control Ventilation is not new, White said, but using CO2 monitors in conjunction with individual VAV boxes has not been done elsewhere.

The PUD’s heating, ventilating and air conditioning (HVAC) uses a system commonly found in large commercial buildings. A large rooftop unit supplies a mixture of fresh and return air at 55 degrees to individual VAV boxes. A thermostat controls the damper in each VAV box to vary the volume of 55-degree air that is supplied to each zone. If the space does not need air conditioning, the VAV box could shut off the flow of 55-degree air to the space, but this would also stop the flow of fresh outside air. To make sure there is enough fresh ventilation air to the space, the VAV boxes are normally set to provide at least 20 percent to 30 percent of the maximum air conditioning needs of the space at all times.

If that amount of 55-degree air is too much, electric heaters will often come on to reheat the previously air-conditioned air. Depending on the season, this can waste electricity and make the space uncomfortably cool. Using a CO2 sensor to control the minimum air flow setting will reduce the amount of over-cooling, while also making sure the space is not over- or under-ventilated.

Oak Ridge National Laboratory launched its crowdsourcing platform in March so innovators like White could present ideas for energy efficient buildings to private and public sector leaders in research and development. The goal is to bridge the gap between cutting-edge ideas and the marketplace.

White presented his concept at the conference and took part in a panel discussion with two other winners and an official from GE.

White has been with Chelan PUD for 17 years, where he manages the PUD’s commercial and industrial energy efficiency program. Through his Resource$mart program, local businesses have saved thousands of dollars in energy costs. Prior to coming to Chelan PUD, White worked as an energy efficiency consultant at PacifiCorp and Portland General Electric, and as a staff engineer at the Governor’s Energy Management Center in Texas. He is a former board member of the Solar Electric Power Association and the architect of Chelan PUD’s award-winning Sustainable Natural Alternative Power program.

The Oak Ridge National Laboratory in Oak Ridge, Tenn., is the U.S. Department of Energy’s largest science and energy research facility. The heat pump water heater – a relatively new product promoted by Chelan PUD – was designed and tested at the lab and is manufactured in the U.S.

Come on in, the water’s fine

Posted in Energy conservation on September 1st, 2015 by Susan – Be the first to comment

 Pool costs drop dramatically with heat pump water heaters

Chelan Hills residents enjoying a dip in the development’s swimming pools are unaware that something else is taking a dive, too – the cost of running those pools.

Heat pump water heaters installed at two pools operated by the Chelan Hills Homeowners Association are proving to be well worth the investment, said Steve Firman, association board vice president who headed up the project.

Chelan Hills residents enjoy this lakeside pool -- and significant energy savings.

Chelan Hills residents enjoy this lakeside pool — and significant energy savings.

The association maintains three parks and two pools for owners of its 500-plus properties and their guests. Before upgrading this spring, pool water was warmed using traditional resistance heaters. As anyone who’s ever tried to keep a pool at a constant 80 degrees knows, that can be a spendy prospect.

With the heat pump water heaters, energy costs for the pools have dropped by 70 percent compared to a year ago, said Jim White, senior energy efficiency engineer for Chelan PUD. That calculation is temperature-adjusted to account for the hot weather experienced in 2015.

Heat pump water heaters work by transferring heat from outside air to water. They’re energy-efficient and quiet.

Two heat pumps were installed at the largest, 54,000-gallon pool in the development’s Division II park. One heat pump is all that’s needed to warm the water at a smaller, 27,000-gallon pool in a small park on the Lake Chelan waterfront.

Firman said the association initially considered solar power but decided against that option due to the number of panels required to heat pools of that size. “The general rule of thumb is twice the surface area of the pool in panels,” he said, which seemed like too many panels for the grounds around either pool. However, “we may add some solar panels in the future to augment the heat pumps and reduce power consumption further,” he added.

Waterbury Pool and Spa of Wenatchee installed the Pentair heat pumps. Electrician Brian Harris of Chelan handled new and re-wiring.

The homeowners’ association spent $24,000 on the heat pump water heater upgrade. Chelan County PUD energy-efficiency incentives covered $11,500 of the cost.

The expected payback is up to five years, but Firman said given the outstanding performance of the heat pumps so far, he’s anticipating three to four years.

“The heat pumps heated the water up faster than expected, they provide consistent heated water, and they’re quiet,” Firman said. “Their performance has met or exceeded our expectations in every way.”

Thanks for saving energy

Posted in Appliances, Energy conservation, Heating and cooling, Lighting on January 28th, 2015 by Susan – Be the first to comment

PrintPopular programs help PUD exceed conservation goal by 40 percent

Here’s a hearty pat on the back to our customers: Chelan County residents taking advantage of energy-efficiency programs saved 13,052,400 kilowatt hours of energy last year – enough to power about 504 local homes.

The savings helped Chelan County PUD surpass its mandated 2014 conservation target by 40 percent and meet a “stretch” goal of 1.49 average megawatts of savings.

Photo of clothes washers

Rebates on energy-efficient clothes washers continue through 2015.

Some 1,490 residents took advantage of programs to save energy and money including rebates on appliances, windows, insulation, ductless heat pumps and air source heat pumps; duct sealing for manufactured homes; and refrigerator/freezer recycling. Thirty-one businesses installed energy-efficiency improvements with help from the PUD.

Rebates and services continue through 2015; check out the many options.

Saving energy is a winning proposition for everyone. Customers save money with lower electric bills, reduce energy waste and in many cases, improve the comfort of their homes. When customers save energy, more power is available to sell at wholesale rates on the open market; those revenues help keep local retail rates low. Customers also help the PUD meet state-mandated targets under the Energy Independence Act.

Space heater pros and cons

Posted in Appliances, Energy conservation, Heating and cooling on December 2nd, 2014 by Susan – Be the first to comment

PrintChoose heaters to suit your needs

Are space heaters efficient and if so, are some better than others? Mark Wiser, the PUD’s senior residential energy adviser, offers this advice:

Photo of space heaterElectric space heaters are all the same efficiency. Electric resistance heat is 100 percent efficient, whether it is a $30 portable heater or a $500 electric fireplace or wall heater. There may be slight variations in energy use from fans versus convective heaters. But if you purchase two products that use the same watts, your electric use will be the same.

Many portable heaters have two settings, one with a higher wattage, say 1,000 watts, and one lower, typically half the watts. The larger will use more energy, but will be better for a larger room. The question is which heater style or design do you want in the room. Some of these heaters are very attractive, but often cost in the hundreds of dollars. If the concern is simply supplying heat, pick the least expensive, UL-approved product of the size needed.

Space heaters always raise a concern about safety. All portable space heaters now have a safety switch on the bottom so if they fall over, the heaters turn off. However, the electric elements are still red hot, so portable heaters should not be placed near flammable objects such as curtains or loose newspapers.  Also, some heaters use “black” heat. These don’t get red hot, but still are hot enough to heat the air. They are hard to find, but may be a safer alternative if young children are in the home.

Space heater safety tips  (Electrical Safety Foundation International)
HVAC vs. space heaters: Which is more efficient? (Department of Energy)

Hot water, hot savings

Posted in Appliances, Energy conservation on November 14th, 2014 by Susan – Be the first to comment

PrintManufacturer markdowns and PUD rebates make it easy on the budget

Manufacturers of  energy-saving heat pump water heaters continue to offer markdowns to make these affordable in the Northwest. Coupled with Chelan PUD rebates of $300 or $500, the cost of heat pump water heaters can be comparable to standard electric storage heaters.

HPWH_VoltexHere are the current discounts:

  • Through Dec. 3, 2014: Save $400 on the GE GeoSpring 50-gallon heat pump water heater. Available locally at Lowes.
  • Through Dec. 15, 2014: Save $300 on A.O. Smith Reliance 50-, 60-, and 80-gallon units. Available to plumbers and contractors purchasing through Ferguson in Wenatchee.
  • From Nov. 28 – Dec. 31, 2014: Save $300 on the 50-gallon Rheem EcoSense (HB50ES) at Home Depot.

After installation, the savings continue: Save up to 50 percent on your water heating costs. Learn about heat pump water heaters and whether they’re right for you at