Top 10 Home Remodeling Don'ts -
from our friends at Houzz
December 17, 2017
Tankless Water Heaters: Should they be on your House Remodeling or Tank Replacement list?
November 7, 2014
Long favored in Europe and Japan, where square footage is at a premium, tankless water heaters provide hot water on demand. According to the EPA, residential electric water heaters are the second highest energy users in American households: "The energy consumed by your refrigerator, dishwasher, clothes washer, and dryer combined use less energy than your current standard water heater."
Tankless water heaters offer big savings in energy use and space. The question is: Can these little units cater to the water-heating needs of larger homes here in New England? Find out if a tankless water heater should be on your house remodeling or tank replacement short list.
What is a tankless water heater, and how does is work?
Unlike standard water heaters that keep water hot and ready for use at all times in insulated 20- to 80-gallon tanks, tankless models don't store hot water, they heat on demand. When a hot water tap is turned on, cold water runs through a pipe into the unit where a flow sensor turns on a gas burner or an electric element to heat the water to the desired temperature. When the hot water tap is closed, the flow sensor turns off the burner.
How are tankless water heaters powered?
Tankless water heaters can be fueled by gas (natural or propane) or electricity. Gas-powered units require venting (just like standard tank heaters). Most gas models also have electronic controls, so an electric outlet is needed. Full electric tankless heaters don't need venting but have minimum voltage and AMP requirements—consult with J&M Construction first to be sure your power is adequate.
Are there different types of tankless water heaters?
Two types of heaters are generally offered: whole house and point of use. Whole-house systems are powerful enough to generate hot water at flow rates to serve a household. Point-of-use units have low flow rates and are designed to supply hot water for a single appliance or location. These compact contraptions are typically installed directly adjacent to wherever they're needed, such as under a sink; they're most often used to augment a system when instant or additional hot water is needed.
How much hot water can a tankless heater generate?
Unlike standard water heaters, which draw on reserves, tankless water heaters provide a continuous supply of hot water. While the stream of hot water is unlimited, tankless models heat and deliver water at a certain flow rate. That output, or capacity, is measured in gallons per minute (gpm). So, while a tankless water heater won't "run out" of hot water like a storage tank can, there may be an issue of not being able to pump out enough hot water for multiple uses at the same time. For instance, a bathroom faucet typically delivers 0.5 to 1.5 gallons per minute of water flow—one of the measurements J&M uses in calculating your household's hot water needs.
What size tankless water heater do I need?
Tankless water heaters are available with different levels of hot water output (measured in gpm and often referred to, confusingly, as "size"). Correct sizing depends on two factors: the level of water flow needed to supply your home and the temperature of the ground water.
Water Flow: The level of water flow required depends on what and how many appliances and faucets (indoor and out) that you have, and whether they're used simultaneously. When calculating your home's water needs, J&M Construction adds together the flow rates of these items to calculate your needs. For example, running a shower (typically 1.5 to 2 gpm), a dishwasher (1.5 to 3 gpm), and a bathroom faucet (0.5 to 1.5 gpm) at the same time requires a total gpm capacity of 3.5 to 6.5 gpm.
Another solution for high-gpm needs is setting up two connected tankless water heaters, or pairing an individual heater with a water-consuming appliance, such as a washing machine, essentially taking it off the family water grid.
Ground Water Temperature: Another factor in tankless water heater output is the temperature of the ground water that feeds the input pipes. Where you live matters. Colder ground water takes longer to heat, which in turn affects speed and flow of the hot water coming out of your faucets.
Some manufacturers are adding built-in recirculation pumps to move water more quickly from the heater to its destination. Speeding up warm water arrival means less water waste.
How compact are tankless water heaters?
Space savings is one of the biggest advantages of tankless water heaters. Unlike their 5-foot-tall, 24-inch-wide monolithic cousins that demand substantial real estate in a home (sometimes their own room), tankless units are wall-mounted and typically measure in at a demure 1.5 feet tall, 24 inches wide, and 9 inches deep.
Tankless water heaters can be installed discreetly in a closet, cabinet, or room without taking up valuable floor space. To maximize hot water delivery, consider installing the system near where it will be used most or in a centralized spot.
Are tankless water heaters more efficient than the standard tank variety?
Yes. A drawback of standard tanks is the energy used to keep the water hot at all times, otherwise known as “standby losses.” Tankless water heaters eliminate these heat losses. The EPA estimates that tankless water heaters offer a 35 to 40 percent energy savings over high-efficiency storage tank heaters.
How much do tankless water heaters cost?
The initial outlay for a tankless water heater averages about $1,000 to $1,200 for a whole-house unit, which is even a bit less expensive than, high-efficiency tanks, which run in the $1,500 range.
While the upfront costs are higher than a standard hot water heater, they're offset by the higher life expectancy of the units over standard tank models and the savings in energy costs. According to the U.S. Department of Energy,most tankless water heaters have a life expectancy of more than 20 years, double that of storage tanks. They also have easily replaceable parts, which extends their life by many more years. The savings in energy costs are currently estimated at $90 per year in an average household. The EPA offers an energy cost calculator for personalized assessments.
Call J&M Construction for a FREE consultation to discuss whether a tankless water heater is the right solution for your home: 203.256.5785