When Madison resident Tom Eggert switched to a tankless water heater 10 years ago, he and his family saw a 35% reduction in the amount of gas they used. "We have six people in our family and we never run out of hot water. It's an impossibility with the tankless," says Eggert, who is both a Policy Advisor for the Department of Natural Resources and Honorary Fellow at the Institute for Environmental Studies at the UW-Madison. If you're looking to save on your energy bill and make your home more eco-friendly, consider changing your water heater from a conventional model to one of the more efficient options available.
Increasingly, newly constructed houses may feature tankless water heaters, sometimes called on-demand or instantaneous. They are designed to heat a continuous stream of water as you need it. You don't have a storage tank and, as a result, you don't have heat losses that occur with the body of standing water that sits in a conventional water heater.
The heating process does not begin until you open a tap somewhere in your house, unlike conventional water heaters, which have to maintain a temperature of 120 degrees (or whatever you've set it to) throughout the day.
Does that mean less hot water with a tankless model? While you will always have hot water available, the flow rate on tankless units can be variable, meaning you won't be able to have hot water to run the dishwasher, take a shower and do laundry all at once. But simple time management can handle that. "If you're not used to thinking about what other hot water uses are happening at the same time, you'll quickly learn," says Eggert.
Tankless units cannot run without softened water. It is also important to note that the units vent outside the house through stainless steel piping, which can factor in to your total cost. If you are planning on installing a tankless unit in an existing home, you need to make sure the gas piping is appropriately sized.
Tankless models range from $800 to $1,400. This type of water heater has been around for over 20 years in Japan and Europe, but have only started hitting the U.S. market in the last 10 years. "The tankless inquiries have gone up exponentially in the last year, but they're still in transition," according to Kevin Burke of First Supply, a wholesale facility in Madison. Jeff Simonson of Simonson Brothers, plumbing wholesalers, finds the tankless models less prone to trouble now than when they were first introduced. "If they're sized right for their application, they're pretty much maintenance-free. They do just fine."
A more common type of water heater is called power-vented, which is similar to a conventional water heater. Both have a storage tank, but the power-vented saves energy by not venting through the house chimney, eliminating a big potential for heat loss. Instead, power-vented models use a small motor and plastic pipe to vent to the side of the house.
Power-vented models have nothing on tankless as far as efficiency goes, however: they're about 10% more efficient than conventional tank-type water heaters, compared to 25% for tankless models, according to MGE.
And when you compare tankless with power-vented for warranty and repair calls, Simonson says, "tankless wins."
Power-vented models cost less upfront, though, ranging from $700 to $1,200, and many models are eligible for "Cash-Back Rewards" through Wisconsin Focus on Energy, says Energy Star project manager Kevin Hogan. "Power-vent are very mainstream; that's the minimum for Wisconsin Energy Star homes, which can't have conventional water heaters installed," says Hogan.
Another high-efficiency option worth considering is going solar. This involves connecting solar panels to your home's existing water heater, providing a renewable source of hot water and making this the ultimate eco-friendly update.
Conversion to solar costs anywhere from $5,000 to $8,000, depending on how many panels you need to operate the heater and where the piping is located within the house.
However, "Domestic solar water heating has the fastest payback. Solar water heaters pay for themselves in six to eight years," says Hogan. You can expect to save $150 to $400 per year on your gas bill.
Plus, solar water heaters are eligible for rebates at tax time. "The state rebates and federal tax rebate can get quite a bit of that [initial] cost back," says Kevin Coleman of the Madison Environmental Group. "The payback time continues to come down as the technology improves."
Coleman recommends getting a solar assessment, especially if you have a shady lot, and says, "You might have a better roof than you think." Solar assessments are given by a handful of Madison-area businesses (a list is available from the Midwest Renewable Energy Association; see RESOURCES below).
If you still have an older tank-type water heater, do you need to run right out and get something better? That depends on the energy-efficiency and age of your current heater.
It's not a good idea to wait to replace until your current model wears out completely. Do some research in advance of replacement so you can choose wisely when the time comes. If your current tank still has a few years to go, there are still ways you can save energy, including lowering the standing temperature, conserving water, and insulating the hot water pipes.
Madison Gas & Electric; 608-252-7117 (Home energy line); www.mge.com/home/appliances/water_heaters.htm; Downloadable primer on water heater options.
Focus on Energy; 800-762-7077; www.wifocusonenergy.org; Info on renewable energy, general home energy efficiency and cash-back reward programs.
Madison Environmental Group; 608-280-0800; www.madisonenvironmental.com
Midwest Renewable Energy Association; www.the-mrea.org; Look under "Resources and Links" and then "Certified Cite Assessors" for a list of businesses that provide solar assessments.
U.S. Department of Energy-Energy Efficiency and Renewable Energy; www.eere.energy.gov/consumer/your_home/water_heating; Guide to new water heaters and hints for improving the efficiency of your old heater. Also a worksheet that helps you determine how large a heater you need for your household.
American Council for an Energy-Efficient Economy; www.aceee.org/consumerguide/waterheating.htm; Excellent guide to replacement options or saving without replacing your current heater.