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Fuel cells operate similarly to conventional batteries in that they have two electrodes (an anode and a cathode) with a conductive electrolyte between them. The only by-product of the chemical reaction between the hydrogen and oxygen is water.
Hydrogen used in fuel cells can be generated from conventional sources of energy, such as natural gas and ethanol. It can also be produced by solar or wind energy. It is possible to use them as the primary source of energy by reforming them into hydrogen at the fuel cell.
Fuel cells were first developed around 1850 and by the mid-1960s were used on Apollo space missions and are still used today for the space shuttle. Fuel cells are currently providing power for buses, commercial buildings, and utilities.
"The most logical future use of the fuel cell will be as a replacement for the internal combustion engine in transportation," Nelson said. "These applications will involve cars and vans, buses and trucks—and possibly even railroad locomotives."
Fuel cell-powered vehicles differ from conventional battery-powered vehicles in that they do not have range limitations nor do they have the long recharging times characteristic of battery-powered vehicles.
"A fuel cell will not run down nor does it require recharging," Nelson said. "It will produce power as long as there is a source of hydrogen. Fuel cells differ from conventional internal combustion engines (ICE) in that they produce power without combustion and have no moving parts."
The major advantages of fuel cells are virtually pollution-free (zero emissions) operation and an energy efficiency roughly twice that of a conventional automobile engine. Also, they are quiet and have no moving parts, which leads to higher reliability and lower maintenance costs.
"And developing and using fuel cells will help decrease our continued dependence upon imported oil," Nelson said, "because we can derive the hydrogen needed for fuel from energy sources here at home. This, in turn, will help our economy."
A fuel cell vehicle has a higher initial cost but a lower projected life-cycle cost than a conventional diesel-fueled bus due to lower operational (no fuel) and maintenance costs over the lifetime of the fuel cell.
"While fuel cells sound promising, especially for transportation needs, we still have to overcome some obstacles before we can use them on a larger scale," Nelson said.
Some of these obstacles include making hydrogen readily available as a transportation fuel on a commercial basis and perfecting reformer technology for on-board generation of hydrogen.
"You can set your room thermostat at the lowest position, typically 45 to 50 degrees," said Richard B. Hayter, director of Engineering Extension at K-State. "Similarly, you can turn the thermostat on your water heater to its minimum position, or completely off."
Depending on your heating system and the construction of your home, it might take a while for your home to reach a comfortable temperature when you return. Nevertheless, your energy cost savings may overshadow any inconvenience.
"When reducing the temperature in your home, you must take particular precautions to prevent freezing in your supply and drain plumbing systems," Hayter said.
Plumbing on inside walls should not present a problem if you lower temperatures in your home. Plumbing on outside walls or in crawl spaces, however, could freeze.
"Occasionally plumbing is located behind cupboards in the bathroom and kitchen," Hayter said. "If these cupboards are located on the outside wall, they reach a temperature colder than other air in the same room."
You can bring temperatures in these cupboards closer to room temperature by leaving the doors to the cupboards open.
Close the main water supply valve to your home during your absence.
"If the main valve is left open and freezing would occur, a rupture in the pipe could cause considerable water damage to your home," Hayter said. "You may also wish to consider putting a small amount of antifreeze in the traps of your waste water or plumbing drains. Be sure that the type of antifreeze you use is appropriate for eventual discharge into your waste water system."
Ask your local plumbing supplier or hardware store about the appropriate type of antifreeze and the quantity to use.
"Although it is not an energy issue, you should create the illusion that your home is occupied while you are away," Hayter said. "Set timers on multiple lights throughout your house to turn on and off as though there were normal activity in your home. Also, be sure that mail and newspapers do not accumulate while you are gone."
"Air finds a variety of avenues into your home. Such leaks are worth fixing," said Richard B. Hayter, director of Engineering Extension at Kansas State University. "They may be increasing your heating costs by 10 percent or more in comparison to a similar house treated for infiltration."
Hayter said techniques for tightening your home could include:
- Controlling air flow through cracks around windows and doors by caulking and weatherstripping.
- Installing quality dampers in chimneys and flues to significantly reduce the amount of air drawn into a house.
- Applying an impervious tape such as duct tape to the seams and joints of duct work in unheated spaces. The seals at the joints of some ducts are poorly fitted, allowing significant quantities of heated air to escape. This is a problem particularly with ducts in unheated spaces such as attics or crawl spaces.
- Replacing worn weatherstripping on doors and deteriorated caulking around windows. This should be a routine maintenance item.
- Putting gaskets around electrical outlets on interior walls and caulk holes made in exterior walls for plumbing and electrical service.
- Less obvious methods can also reduce infiltration significantly. A home protected by landscaping or natural barriers that reduce the force of the wind will have less infiltration.
"There is some concern that a home can be made too tight," Hayter said, "so that pollutants produced during normal household activities can become health hazards. This is rarely a concern with existing homes. Newly constructed homes built with techniques for reducing infiltration may need special ventilation to maintain air quality."
"Without proper treatment, no washable filter will do an adequate job of cleaning the air," said Gene Meyer, extension mechanical engineer at Kansas State University.
There are two types of washable filters. One is an aluminum mesh in a rigid frame. The second is a flexible polyurethane filter with no frame.
"To make a washable filter effective in removing dust from the air stream, it needs to be coated with a filter adhesive," he said. "This is a water soluble adhesive that you spray on the filter so dust will stick."
The adhesive is available from hardware stores and heating and air-conditioning suppliers.
Throw-away filters either have smaller air passages or are already treated with the adhesive.
"Properly applied, a plastic covering over a window can make the window almost airtight and is one of the most effective ways to seal a leaky window," said Doug Walter, president of Kansas Building Science Institute, Manhattan.
A storm window is designed more for convenience than airtightness.
"Even the highest quality storm windows allow air to leak around the edges of the sashes," Walter said. "But, storm windows typically reduce air leakage through primary windows by about half."
You can install window plastic either inside the window or on the outside.
"Outside installations tend to be the most difficult to maintain through the winter," he said. "Cold temperatures can make the plastic brittle and gusting winds whip the plastic in and out, reducing the effectiveness of the seal and sometimes even tearing the plastic."
"Newer plastics are very clear when stretched tight, removing most objections to their appearance," Walter said. "You can shrink film plastic with a blow dryer, eliminating all wrinkles and making the plastic almost invisible.
"It is important to adhere the plastic to the frame surrounding the window rather than to the window sash itself for maximum reduction in air leakage," he said.
"You use the defroster to solve two visibility problems," said Gene Meyer, extension mechanical engineer at Kansas State University. "The first is to remove ice from the windshield. The second is to prevent condensation of moisture on the inside of the windshield. You don’t need to use the air-conditioner for the first, but it helps with the second."
Moisture collects on the inside of a windshield (fogs up) when the windshield temperature is below the dew point of the air inside the car. You prevent the problem by raising the temperature of the windshield or by removing some of the moisture in the air inside the car.
Directing heat to the windshield helps raise the windshield’s temperature. Older cars did only this. However, by first cooling the air with the air conditioner, your car removes moisture, too. It then heats the air before directing it to the windshield.
"The dew point of the air in your car is now lower, preventing condensation or even clearing moisture that has collected," Meyer said.