Top 6 strategies for an energy-saving water heating system
Everyone loves a nice hot shower, but the cost of heating that water is the second largest in the average US household, after space heating and cooling, according to the U.S. Department of Energy. Fortunately, new technology offers homeowners a way to save by delivering hot water at a lower cost.
According to the U.S. Environmental Protect Agency, water heating accounts for about 13 percent of a typical utility bill or up to 25 percent of the energy consumed in the home.
You can reduce your monthly water heating bills by selecting the appropriate water heater for your home based on energy-efficient water heating strategies.
This exclusive article from ProudGreenHome.com reviews of the top eco-friendly water heating strategies available to homeowners and building professionals today.
Hybrid Heat-Pump Water Heaters
For consumers who do not have access to natural gas but desire greater energy savings, a hybrid electric heat-pump water heater may be the best choice.
The hybrid technology absorbs heat in surrounding air from the home and transfers it into the water. It also uses standard resistance elements immersed in the tank, but only when a faster recovery is needed. Since the heat pump requires much less energy than conventional electric resistance elements, hybrid electric water heaters are much more efficient and more economical to operate.
|GE manufactures the GeoSpring™, a hybrid electric ENERGY STAR®-qualified water heater assembled in the U.S.|
GeoSpring1 saves homeowners an average of $3652 a year in utility bills.Marketing Manager for GE Water Products Francois Lebrasseur said, "With the GeoSpring's advanced heat-pump technology, a consumer can save over $3,000 in a 10-year span. The savings can be used toward a vacation, shopping spree, home improvement or rainy-day fund."
A standard electric water heater cost an average homeowner $585 every year to operate. The GeoSpring uses 62 percent less electricity than a standard electric water heater, costs in average $220 to operate annually and typically pays for itself in less than 3 years.
Homeowners can further fine tune their savings with the GeoSpring's control panel. The temperature can be adjusted in 1-degree increments up to 140 degrees for just the right amount of hot water for the home. If you"re going out of town, use Vacation mode to lower the water temperature to 50 degrees for the duration of a trip. GeoSpring will then automatically reenergize itself the day before the homeowner's return.
Experts recommend replacing a failed water heater with one that uses the same fuel, electric or gas. Heat pump water heaters like the GeoSpring offer a step-up in efficiency for electric tank water heaters.
Its size and footprint make it an easy replacement because it provides the same amount of hot water as traditional 50-gallon standard electric water heaters and uses the same electrical and water connections as a standard electric water heater.
"Water heating systems aren't all created with efficiency in mind, and a cheaper unit up-front may end up costing you a lot more in operating costs. The GeoSpring is a savvy investment that helps homeowners save money over time," Lebrasseur said.
1) For more information, visit www.geospring.com
2) Based on DOE test procedure and comparison of a 50-gallon standard electric tank water heater using 4879 kWh per year vs. the GE® GeoSpring™ Hybrid Electric Water Heater using 1830 kWh per year and an average electricity cost of $0.12/kWh
Electric Tankless Water Heaters
Tankless water heaters are considered among the most energy efficient options on the market. Also known as on-demand water heaters, the tankless option heats water only when it's needed. That saves the energy wasted in maintaining a tank full of water at a high temperature.
EcoSmart Whole House Water Heater
A tankless water heater offers more options than a whole house tank water heater. Companies like EcoSmart offer a range of electric tankless water heaters that fit many applications. For instance, smaller point-of-use options work well in supplying hot water for a kitchen or bathroom that’s distant from the rest of the house or may need a steady supply of hot water. Larger units can take care of a whole house or the bathrooms clustered together in section of a home.
One of the many advantages of an electric tankless water heater is the ability to install the heaters closer to the point of use,” said Jens Bolleyer, vice president of marketing for EcoSmart. “This reduces the amount of travel time within the pipes and provides hot water more quickly to the point of use. Because electric tankless water heaters eliminate stand-by loss and cycling loss and only heat the hot water that is demanded they can reduce water heating costs by up to 60 percent.”
In addition to the basic energy-saving benefits of a tankless water heater, the EcoSmart option provides intelligent self-modulating controls for greater savings. Unlike many other tankless models, the EcoSmart water heaters use a flow sensor that modulates the energy consumption based on demand. Without the smart sensor, the water heaters are either fully on or fully off, which can use too much energy for the task at hand. The smart sensor also eliminates the problem of cold-water rush that’s common with tankless water heaters. The cold-water rush happens when low water pressure does not activate the unit or in mixing in cold water the hot water flow is reduced. If the hot water flow falls too low, the unit turns off, which produced a cold-water rush. The EcoSmart’s sensors operate at a much lower hot water pressure, which avoids the cold-water rush.
Radiant floor heating is become a more popular options, and the EcoSmart tankless system can support this form of heating. In the hot water or hydronic radiant floor system, water circulates through tubes embedded in the floor. This water can be supplied from many sources, including boilers, geothermal and solar thermal systems as well as gas and electric water heaters.
Ecosmart's heaters are an efficient choice because they operate on "closed loop" systems based on the fact the self-modulating technology can read the inlet water temperature, flow rate and output setting to calculate the amount of energy needed based on the demand.
As the water circulates through the system and re-enters the heater, it’s warmer and warmer, so the heater will consume less energy for greater efficiency and cost savings. This also eliminates the need to keep a large tank or boiler continuously hot because tankless water heaters provide endless hot water on demand.
Gas Tankless Water Heaters
Gas tankless water heaters offer many of the same advantages as electric tankless water heaters. New developments have made some gas tankless water heaters even more efficient. For instance, Bosch has developed condensing tankless technology that recaptures heat from the exhaust gas. The system uses the latent condensation heat to preheat incoming cold water which makes it 10 percent more efficient than non-condensing tankless water heaters.
Non-condensing gas tankless water heaters also offer a high-efficiency option for homeowners as well. For many homeowners, a tankless water heater, regardless of the fuel option, represents a smart choice.
Solar Water Heaters
Solar water heaters are a good option for most climates when paired with a supplementary system such as a tankless water heater. Depending on the climate a solar water heating system can provide 100 percent of a household’s needs. During overcast days the system will pick up a surprising amount of sunlight. When the system doesn’t produce enough hot water, an efficient tankless water heater can take over the load.
A solar water heating system is usually mounted on a south-facing roof, but it’s no problem to install on a roof that’s up to 45 degrees off of due south. Bosch Thermotechnology’s residential solar water heater systems offer domestic hot water, space heating and even pool or spa heating. A solar water heater is often a good match with a radiant floor heating system for even, comfortable heat.
|Bosch Thermotechnology’s residential solar water heater systems offer domestic hot water, space heating and even pool or spa heating.|
Solar water heaters are more common in Europe and the Southwest U.S., as well as Hawaii where many homes enjoy the benefits.
The ROSE Cottage, a net-zero home built in New Hampshire, employed a Bosch Buderus solar water heating system that provided domestic hot water.
On-demand Hot Water Recirculation Pumps
Some water heaters are more efficient than others, but no matter what type of water heater is used in a home, an on-demand hot water recirculation pump can make that water heater more efficient and last longer.
ACT D’MAND KONTROL SYSTEMS developed an electronically controlled recirculating pump system capable of distributing hot water on demand, without gallons of water needlessly going back into the sewage system.
The pump is installed into the home's plumbing system, usually near the farthest fixture or at the end of the dedicated return line. The pump simply moves the hot water you already have through the plumbing system faster, without wasting hot water. The pump can turn on when you need it via a push button or occupancy sensor and turns off when the hot water reaches the fixture.
The system works with existing and new plumbing systems, including boilers and tank or tankless water heaters, gas or electric. The ACT D’MAND KONTROL SYSTEMS can also be used on “Structured Plumbing®” where a dedicated hot water re-circulation (third line) has been installed.
ACT D’MAND KONTROL SYSTEMS have been proven to save both water and energy in a test conducted by Oak Ridge National Laboratory, funded by the U.S. Department of Energy, according to Larry Acker, CEO.
Approximately 7 gallons of water down the drain creates 1 kilowatt-hour of lost energy, which according to the DOE, represents 1.5 pounds of carbon dioxide.
Of the 90 million single-family homes in the United States, most have systems requiring homeowners to wait up to a full minute, if not longer, for water to heat from 50 degrees to 120. In an instant-gratification society this is inconvenient, not to mention wasteful of natural resources.
ACT D’MAND System creates benefits directly for water heaters. These occur several ways, depending on the water heater being either a tank type or tankless water heater.
Tank Type Water Heaters
If the tank type water heater is gas or electric the direct saving or benefits by using the ACT D’MAND System will vary. In both cases moving the water quickly to the fixture from the water heater prevents the water heater from firing or heating water that is being wasted down the drain waiting for hot water. This also prevents much colder water from entering the water heater as you run the water down the drain waiting for hot water.
The water that is returning to the water heater while the ACT D’MAND System is running is water already in the water lines in the home. Nothing is going down the drain while you are waiting. The savings is of both water and energy in the area of about 10 percent savings.
The other advantage is the water being returned to the water heater is moving faster than the fixture will allow, because most fixtures are low flow with average of 1 to 2 gallons per minute, compared to the flow of hot water through the water heater at around 5 gallons per minute. This keeps the water heater sediment build up from occurring, which will add over 25 percent more life to the water heater.
Because electric water heaters use more expensive fuel than gas type water heaters the savings by using the ACT D’MAND System is greater.
Tankless Water Heaters
Tankless water heaters are considered flash heaters and have entered the US market with over 2 million in sales in the last 10 years. The homeowner enjoys the fact that the tankless water heaters will give endless supply of hot water, “never to run out of hot water again.”
Even though the energy efficient has been rated higher than a standard tank type water heater, the actual cost of operation may be higher than a tank type water heater. This is due to the maintenance of the tankless gas water heater, which is much higher and over a 5-to-10 year period cost of operation may be higher than the tank style of water heater. Because the tankless water heaters operate with burners that can reach almost 200,000 BTUs, the manufactures will void their warranty if a pumping system is used with their product.
The exception is the ACT D’MAND System, as it actually delivers a 10 percent savings to the tankless water heater by not allowing the much colder water from entering the water heater prior to the actual use of the hot water by the user and only running on the demand of user. Preventing the water from going down the drain stops the colder water from going through the water heater, which creates an additional10 percent energy savings. There is an another benefit to the water heater by not allowing the water heater to burn or run for any extended amount of time. Tankless water heaters also have a delay period before the flow activator will allow all the burners to go on unnecessarily.
The system for residential and commercial applications can be installed on existing homes and buildings. This allows the existing plumbing in a building to circulate the hot water to remote fixtures by using both the hot- and cold-water piping. This is accomplished without allowing any hot water to enter into the cold-water side.
Bosch Thermotechology offers a different take on hot water recirculation with its mini tank water heaters. These small point-of-use electric water heaters can be combined with a larger water heater in the basement to eliminate waiting for hot water. The on-demand heater supplies the initial load of hot water until the main water heater is able to take over and fulfill the demand.
Shower Water Heat Exchanger
Every time you take a shower, you waste energy. You’ve most likely used fossil fuels to heat the water to a comfortable temperature, and then let it run down the drain. All that heat is lost as the water flows into the drain line and into the water treatment system.
Several years ago, an engineer knew he was wasting energy with each shower and decided to do something about it. After 4,700 tests and modifications, the EcoDrainTM was ready to enter service.
The EcoDrainis a patent-pending heat exchanger that transfers heat from hot shower wastewater to cold incoming water. This cuts water heater use for showers by 25 percent to 70 percent.
“The savings vary by energy prices and amount of use,” said David Velan, president of EcoDrain. “If you’re using electricity to heat water, you’ll save more than gas, and if there’s more than one person in the home you’ll save more as well.”
After all the experimentation, the EcoDrain team found a solution that optimized the internal heat-exchange channels. These flattened, sealed channels maximize the surface area of the heat transfer space and to create optimum flow turbulence in the outgoing wastewater and incoming fresh water.
The EcoDrain is a small, easy-to-install device with no moving parts in the drain line. It’s installed horizontally in the shower drain line with a connection to the fresh cold water line feeding either the hot water heater or the shower mixing valve.
The EcoDrain is installed directly in the shower drain line and features a double wall of separation between fresh and waste water to eliminate the possibility of mixing, plus an interior non-stick coating to prevent soap, hair or debris collecting inside.
It’s designed for use in a shower where there is significant hot water that is drained without delay. Heat from the shower water drain is transferred immediately. In other potential applications such as a bath, hot tub or a clothes washer, the hot water is not drained immediately so there’s not as much opportunity for heat transfer. That’s why the EcoDrain is usually installed in the shower drain line.
It can be used with just about any water heating system on the market, including tank, tankless and solar thermal. It’s recommend to install it in new construction or during a major renovation, depending on the access to the drain lines. Customers have paired EcoDrain with heat-pump tank water heaters to recapture waste heat to reduce the load on the heat pump, Velan said.
Velan compared the EcoDrain to the heat recovery ventilators that perform a similar function in a heating and air conditioning system. The HRV captures energy in the exhausted air and transfers it to the incoming fresh air, saving energy used for heating and cooling.
“Why waste the energy you’ve put in getting the air temperature just right?” Velan said. “The EcoDrain does the same thing, it captures the energy in the water that would otherwise be wasted.”
Read more about energy-efficient water heaters.
Gary Wollenhaupt is an experienced writer and editor, with a background as a daily newspaper reporter as well as corporate and agency public relations and marketing. He is constantly looking for affordable green upgrades to make to his home in eastern Kentucky.www