Picture this: You are preparing for work, taking a nice hot shower when the water suddenly goes icy cold. Oh no, that old water heater has finally quit for good.
Now you are challenged with making choices, selecting and replacing the water heater. This is a great opportunity to select one that is energy efficient -- allowing you to have hot water and to save money too.
Keep in mind that this is an important decision, becuase it generally is one you will only need to make every 10 to 15 years. So choose carefully!
What’s available?
Storage Water Heater: A conventional water heater
Check www.aceee.org/consumerguide/topwater.htm for more information on conventional water heaters.
Pros of a conventional water heater
- Readily available hot water
- Pipes and unit can be insulated readily
- Available in different sizes for different needs
- Most plumbers know how to install them
- Variety of price points
- Some are Energy Star rated
- You can install a timer to turn it off when you are away
- Electric or gas types
- They generally are rated for efficiency of use, so you can compare the energy factor on the Energy Guide label
Cons of conventional water heaters
- Large unit that takes up space
- Inefficient, because you are paying to keep water hot even when not in use
Solar water heater: Use the sun to help provide hot water
Check www.eere.gov or www.realgoods.com/renew/shop/list.cfm?dp+2200 for more info on solar heaters.
Pros of solar water heaters
- The sun is free
- Over the long term can reduce water heating bills by 50 to 80 percent
- Available in passive solar and active solar
- Preheat the water before sending it to conventional water heater
- New technology developed all the time
- Energy efficient
- A "green" solution – less impact on the earth
- IRS tax credit available
Cons of solar water heaters
- Expensive, costs more initially
- New technology
- Can be complicated or simple, depending on system
Tankless Water Heaters (also called Demand or Instantaneous Water Heaters)
Check www.eere.energy.gov a link to many consumer-based articles on this government site.
Pros of tankless water heaters
- Fairly new to the United States but used in Europe and Japan for many years – well tested
- Only occupy a little space
- Heat water as needed
- Gas- or electric-powered types available
- Very energy efficient
- Contractors are becoming familiar with them
- Wonderful concept
Cons of tankless water heaters
- Will only supply a set amount of heated water per minute
- New (people here don't have as much experience with them)
- Gas types require a way to vent them
- Expensive
- Not a good choice if hot water needed for several purposes at same time
Heat Pump Water Heaters (also called Earth Coupled Heat Pumps or Geothermal Heat Pumps)
Check http://www.aceee.org/consumerguide/
waterheating.htm#most_hpwh
for more information.
Pros of heat pump water heaters
- Use the natural heat storage capacity of the earth or ground water to provide energy-efficient heating and cooling in addition to heating the water in the house
- Very energy efficient
- IRS tax credit available
Cons of heat pump water heaters
- Require more space
- Expensive
- Not commonly used in area
Factors influencing your decision:
- Fuel source
- Hot water needs
- Compatibility
- Energy efficiency
- Warranty and life of heater
- Your budget
Fuel Sources
Your first choice is deciding the energy source in your house. Do you want this water heater powered by gas or electricity? Many homes are all electric and have no gas lines available. Do you have gas lines available or should you decide to install them? What is the fee for connection? How do natural gas prices compare to the price of electricity? Are there any other installation charges or fees?
Hot Water Needs
On conventional water heaters look at the First Hour Rating (FHR). This tells you how much hot water a heater can provide per hour. This is located on the Energy Guide label. Note: the FHR is not the same as the tank size; most have an FHR number greater than the tank size. As far as what you need:
-
2 people: 45-55 gallons
- 3 people: 55-65 gallons
- 4 people: 65-75 gallons
- 5 people: 75-85 gallons
- 6 people: 85-100 gallons
- 7 people: 100 or more gallons
Tankless water heaters vary in the number of gallons that can be heated per minute. Generally, the gas ones heat slightly more water per minute than the electric ones.
Compatibility
Do you have access to the gas line available or the space needed? Are you building a new home or installing in an existing one? Do you have the ventilation to the outside necessary for the use of a gas-powered system?
Energy Efficiency
Purchase the most energy efficient unit you can afford. With conventional storage water heaters, look for the “Energy Factor” (EF) number. It describes how efficiently a water heater operates. The number ranges between 0 and 1 -- the closer to 1 the more efficient. With electric storage water heaters, look for an EF of at least 0.93; with gas powered ones, look for an EF of at least 0.63.
Tankless water heaters have no standard system for measuring efficiency. Pay attention to the flow rate in relationship to temperature output. If you choose a gas-powered water heater, keep in mind electronic ignition units are more efficient than those with pilot lights.
Warranty and Unit Lifetime
Purchase a unit that has a longer warranty, because these usually are made of heavier materials that will last longer. The average lifetime of a storage heater is 10 to 15 years, and the tankless ones generally last more than 20 years.
Your budget
Look at your budget and compare the cost of buying and installing a unit, fuel prices, maintenance costs, warranties, fuel efficiency and expected lifetimes. Also, consider how long you will be in the home to see if you will be there long enough to experience long-term savings.