Coast EPA News

Tankless Water Heaters-Does The Technology Really Deliver?

03/05/10

An unlimited supply of hot water definitely sounds like a sweet deal to many homeowners. Reduced water heating costs, instantaneous hot water on demand, and more space in the utility closet are all promises made by companies selling tankless water heaters. But does the technology really deliver?

Unlike traditional electric resistance or gas-fired water heaters, tankless models do not store hot water?they heat water only as it’s consumed. One or a series of heating elements within a tankless water heater are activated when a hot water faucet or valve is opened. The unit heats water until the faucet or valve gets closed.

An unlimited supply of hot water sounds great, but generally doesn’t make for responsible water use, particularly in areas of the country suffering from drought or chronic water shortages. Moreover, even the largest whole-house unit may not supply enough hot water for simultaneous, multiple uses.

The important information to understand is a tankless unit for a residential home has a flow rate of about 4gpm at the outlet and will only raise the water temperature around 45-50 degrees. Depending whether you are on public utility water with a 60 degrees inlet temperature or a private well at 50-55 degrees inlet temperature will decide if you get 95 degree water or 120 degree water at the faucet. For example, such a unit may be able to supply only two showers simultaneously or perhaps one shower, a dishwasher, and a sink. If users demand too much water, temperatures will drop. As a result, a tankless system probably won’t meet the needs of a large family.

In addition, water temperature depends on the volume coming out of a faucet. If you turn on the faucet only a trickle, water runs cold. If you open the faucet further, you will trigger hot water—the hottest possible. If you open the faucet to maximum, the temperature will drop back a bit. If you open more than one faucet, temperatures will drop even more.

Hidden Costs

Generally, tankless water heaters do not require a lot of space (a large unit can fit in an area no larger than 24 inches square, and extend from the wall about 8 to 10 inches). But they do require an upgrade in electrical service?something most home improvement stores often don’t mention and a chief reason electric co-ops generally don’t recommend the appliances. This means consumers who want to replace an existing conventional water heater with a tankless unit or add one as part of a home-remodeling project will incur additional costs.

An electric tankless whole house water heater, in most cases, must have three 40 amp breakers to operate, one for each element. This 120 amp set up causes a home owner to increase the house power panel from a standard 200 amp service entrance to a 400 amp. The wire size recommended for a standard whole house electric tankless water heater is #8 copper. The cost for #8-2 copper wire is around $.86 per foot. With three 40 amp breakers it will cost approximately $2.58 per foot to wire all three breakers.

Let’s take a look at the cost for a normal installation of a tankless unit. A tankless unit $700, breakers $24, wire $103, upgrade to 400-amp panel $605 for a total without labor to install is $1432. A standard 50 gallon water heater cost $400, breaker $8, drain pan $20, insulation blanket $20, timer $50 for a total without installation cost of $498.

Comparing an installation of a standard tanked water heater versus an electric tankless it would cost on average $934 more to install a tankless unit. According to many retail plumbing stores and energy experts, there are no savings for a standard family of four, and in most cases the energy use increases as well as volume of water. In cases where the energy use actually drops is when a smaller 2 element unit is used in an apartment by a single occupant or in a retirement situation with only two occupants with very limited use.

If a tankless water heater is installed in an existing home without upgrading the electrical service, low voltage or sudden voltage drops are likely. This will cause dimming lights, blinking lights, and other problems.

While gas-fired tankless water heaters generally do not need basic service upgrades, the same considerations must be made when determining how many hot water faucets will be turned on at any given time and how far away the tankless heater remains from sinks and showers.

Other Options

Consumers looking for an efficient water heater should consider a heavily insulated electric resistance unit or high efficiency heat pump water heater. Solar water heating is also a viable option.

To reduce home water heating costs, the Oak Ridge National Laboratory suggests simple and inexpensive measures such as tank insulation, temperature setback, timers, heat traps, and low-flow showerheads. All of these are more practical and provide a greater return on investment than putting in a tankless water heater.

More cold weather means more high bills

03/04/10

Coast Electric CEO Bob Occhi discusses the cold weather and high bills.

If most of you are like me, you think it is high time for spring to bring warmer temperatures and sunshine. South Mississippi residents have experienced one of the coldest winters in decades and our electric bills are reflecting that cold weather.

After such a cold January, I had hoped February would give us a little relief from the cold but temperatures remained at or below freezing for a prolonged period of time, making heaters work over time. When heaters work hard, bills will be higher. There is not much we can do about the weather but there are some steps you can take to control your energy use that can help keep your bill in check.

Our Web site is such a great resource to our members. The following are just some of the things you can do on the site:

- Learn about Time of Use (TOU) rates. This rate is an alternative to our traditional rate and allows members to save if they use energy in off-peak times. You will probably have to make a few lifestyle changes but those changes could help you save a bundle. Some of our members are already sending in great reports about how much they have saved by changing not how much energy they used but when they used that energy. Look for upcoming stories detailing how they were able to save with TOU rates. TOU rates are a pretty revolutionary option in our state and I believe many of our members could greatly benefit from making the switch.

- View our new Touchstone Energy “Together We Save” materials that provide simple solutions to managing energy use and costs. Nothing suggested will cost you lots of money and you won’t need a professional to make any of the recommended changes to your home. You may just need a tube of caulk and a greater awareness of how your behaviors can affect costs to save.

- Check out our interactive calculators. See how bumping your heat setting from 70 to 68 degrees or sealing a leaky window can help you save.

- Get your kids interested in energy efficiency with Kids Corner. Saving can be easier if the whole family is in on the act.

- Download one of our energy efficiency guides or publications. There are several available.

- Learn how you can get one of our energy efficiency experts to visit your home and conduct a free energy audit and make savings suggestions specific to your house.

- Learn about our Comfort Advantage program to build your home to our efficiency standards.

- Find phone numbers of local agencies that can assist you in paying your bill.

None of us want high bills and the financial burden they cause but if we work to manage or change our patterns of use, we all have the potential to save.

Mississippi Appliance Rebates

03/04/10

The State of Mississippi will implement a mail-in rebate program to help residents replace old, inefficient appliances with new, ENERGY STAR^® qualified appliances. The program is scheduled to begin in April 2010 and will continue until funds are depleted.

Eligible products include

Refrigerators
Freezers
Clothes washers
Dishwashers
Room air conditioners
Gas storage water heaters
Gas tankless water heaters
Electric heat pump water heaters
Gas Furnaces
Central air conditioners
Air source heat pumps
Geothermal heat pumps

Participating retailers, contractors and vendors will be required to properly recycle appliances during the promotional timeframe.

Contact: Mississippi Development Authority

Total Funding: $2,820,000

Program information subject to change. Rebates may be offered for a limited time only. Before purchasing a product, check with your program sponsor to ensure rebates are available, and to confirm product eligibility and program requirements. Products purchased must meet efficiency criteria as established by the state.