The Pros and Cons of Tankless and Regular Water Heaters
Water heater options for homes are more diverse than just the old tank the heats water. There are tankless water heaters, solar powered water heaters, heat pump water heaters, and geothernal heaters. For most homeowners the choice narrows down to tankless versus tank storage water heaters.
Heating water is the second largest expense for most homes and costs homemowners $400-1000 annually. You’ll need to consider the pros and cons of each type to make a final decision.
What’s The Difference?
You’re familiar with traditional water heaters that store water in a tank and use gas fuel or electricity to heat the water in the tank. When you turn on the hot water tap, water heated from the tank flows through the tap.
Tankless water heaters rely on heating water as it flows through pipes, with no storage tank, to send hot water to your tap. The heating unit, using either gas or electricity, heats the water as it flows through the pipes. This water heating system is also called on-demand water heating. It heats the water when you need it.
Both types of water heaters have benefits. Selecting which type to purchase depends on factors like your budget, availability of energy source, and household demand for hot water.
Rinnai Tankless Water Heater
The Environmental Protection Agency (EPA) suggests that a tankless water heater “can be 24%–34% more energy efficient than conventional storage tank water heaters” for households that use less than 41 gallons of hot water. You probably don’t know how much hot water your family uses per day, but here are estimates done in a recent study by the Florida Solar Energy Center:
- Three adult occupants, no kids: 46.6 gpd (176 L/d)
- Two adults; one child: 41.2 gpd (156 L/d)
- One single parent: two children: 35.8 gpd (136 L/d)
- Two adults: one teen: 59.6 gpd (226 L/d)
- One single parent; two youths: 72.6 gpd (275 L/d)
So, the size of your family and the number of appliances that use hot water like washing machines and dishwashers will impact your use. Even so, households that use up to 81 gallons per day still see an energy savings of 8 to 14 percent. You can increase the energy efficiency by installing additional on-demand water heaters to serve hot-water guzzlers like a washing machine or from the above statistics the teenager’s bathroom shower.
Since water heats as it flows, tankless water heaters don’t run out of hot water. Once a conventional water heater’s tank is emptied, you need to wait for more water to heat.
Although the initial cost is higher than a conventional water heater, lower energy use and operating costs, offset the difference over the longer life of tankless water heaters of 20 years or more.
Typical Gas Water Heater
Conventional Water Heater
Conventional water heaters have two major benefits
- The up-front cost is substantially lower. This means your current budget won’t get such a big hit.
- The flow rate is higher than a tankless water heater. This means you can get a good, strong flow of water in your shower.
Mis-Wired Electric Water Heater
The flow rate of tankless water heaters is not as full as a conventional water heater. This means you can have hot water in your shower but not a full blast. You need to factor the gallons per minute you use. For large households this can be quite a lot of hot water, for instance, if two people are showering while the washing machine is running.
You can overcome the flow rate issue by installing serial tankless heaters.
Conventional tank water heaters cost more to run. They use more energy. The initial savings your from purchase can be offset over the life of the water heater by long-term higher energy costs.
Also, tank heaters can develop leaks that cause damage to flooring and walls with potential for mold. On rare occasions, tank heaters can explode causing damage to your home and severe burns to nearby family members.
Consider Your Flow Rate Requirements
You’ll Need To Do Some Math
Calculating the long-term costs requires collecting some hard data about your home hot water usage. Water flow is a major consideration for tankless heaters. Knowing how many gallons per minute your appliances like a dishwasher and washing machine use will help you calculate if you need one or more tankless heaters.
The EPA suggests:
Typically, a 70ºF (39ºC) water temperature rise is possible at a flow rate of 5 gallons per minute through gas-fired demand water heaters and 2 gallons per minute through electric ones.
Budget conscious buyers may look to a conventional water heater investment even though the long-term costs of usage are higher.
The lowly and usually hidden water heater does a lot of work for you home. Consider all the factors before you decide. Then enjoy your hot water for years to come.
Need to check if your current water heater is up to snuff? A home inspection check up is a great way to know if the one you have now is in good shape. Call us today to set up your appointment at (510) 200-7555.