In green building it is important to know the best time to plan upgrading home elements based on their life expectancy. A second factor is knowledge of what is being wasted by their inefficiency.
A water heater, for example, has a life expectancy of 11 years if electric, 10 years if gas, and 20+ years if tankless. Conventional water heating is the third highest home energy expense. Epa.gov provides a great fact sheet for comparing various types. The cheapest initially is the standard tank water heater. An $800 tankless water heater plus installation cost lasts the longest, is best for unlimited hot water, and costs about half as much to operate. The most efficient using electric energy are heat pump water heaters. The most expensive to install is a solar system at $2,500 installed, but it is best for energy savings which will be as much as 80 percent on water heating cost, rising energy costs will not affect you, and it uses renewable energy, not fossil fuels.
Heating and air conditioning units last 15 years if warm-air electricand central air conditioning, 16 years if a heat pump, 18 years if warm-air gas, and 20 years if warm-air oil. A geothermal heat pump saves the most energy but is not cheap to install. An Energy Star-certified system saves 20 to 30 percent on heating and cooling. Save money on both initial cost and utility bills by getting a more efficient system with a smaller-size unit.
Washers’ life expectancies are 10 years; dryers 13 years. For the least use of water and energy, get a front loader washer or second choice is a high-efficiency top loader. Energy Star washers save $550 in water and energy costs over their lifetime. The best energy saving dryer has a moisture sensor to shut off the machine when the clothes are dry.
Refrigerators last 13 years and use the most kitchen energy. Energy Star refrigerators use less than half the electricity of similar prior to 1993 models. Side-by-side refrigerator freezers are the least efficient compared to top or bottom freezers, and through the door icemakers use more energy than refrigerators without that feature.
Toilets have an unlimited life expectancy with 10-year maintenance on working parts. A WaterSense label indicates a toilet that will use 20 percent less water, and dual-systems provide a flushing choice of .9 gallons or 1.6 gallons depending on how much is needed, both much better than the old 7 gallon flushes of toilets before 1994. Look in the tank for the date the toilet was made.
Faucets in the bath or sink last 20 plus years, but a WaterSense high-efficiency faucet and aerators reduce water use by over 30 percent. One drip per second wastes over 3,000 gallons of water in a year. The rate of flow of faucets before 1994 is 3 to 7 gallons a minute; required by federal law now are faucets with 2.2 gallons per minute flow rate. Showerheads last a long time, but one with a dual control lever can adjust the flow from 2.5 to less than 2 gallons per minute. It feels like a higher flow rate because of larger water droplets at higher speed.
Some other life expectancies are 15 to 20 years for aluminum windows; 30 plus years for wood windows; 9 years for dishwashers; 13 years for electric cooktops; 15 years for gas cooktops; and roughly 10 years for magnetic induction cooktops. When replacing a working appliance, donate to others through a charity or Freecycle. If it is not working right or is broken, recycle through the municipal solid waste agency, The Steel Recycling Institute, or Earth911. In Greenville, South Carolina, Duke Energy has upped the incentive on taking old refrigerators and freezers.
Other companies in the Greenville area which help keep home systems upgraded are Benton Green Energy which does home energy audits to identify where a home is wasting energy, JL Design Builders & Renovations does green renovations, All Clear Plumbing does Water Sense plumbing, and iEnergy does free home analysis for a whole house energy management system.