What is a Tankless
Water Heater?
A traditional water heater consists of a large tank in which
80 gallons of water (or more) is heated and maintained at a set temperature,
typically using gas or electricity. This water tank supplies your family’s
needs for hot water for bathing, washing dishes, doing laundry, etc. Once the
heated water has been drawn
from the tank, you must wait until it refills and the entire tank of water is
heated 
A tankless water heater (also called an instant or on-demand
water heater) provides hot water only if and when hot water is needed in your
home. When you turn on a faucet, shower or appliance, water is heated instantly
as tap water passes through “capillary-like” pipes heated by either electric
coils or a powerful gas burner. Water does not sit in a large tank where it is
continuously heated to a set temperature and maintained until needed.
Tankless water heaters can be installed either as
whole-house systems (often consisting of three or more units each serving a
part of the house). Smaller tankless units can also be installed at the point
of use (for example, the kitchen sink, a shower or bathroom, etc.).
Advantages of a
Tankless Water Heater
Tankless water heaters offer several advantages:
1.
They provide an unlimited supply of hot water
only when and where it is needed.
2.
They heat only the amount of water needed at a
particular time.
3.
There is no need to continually reheat the water
in a tank in order to maintain it at a set temperature.
4.
Because water is heated at the point where it is
used, the water is hotter (it does not cool as it passes through a long network
or pipes from the water heater to the faucet).
5.
Therefore, it is more energy-efficient and more
efficient in consumption of water.
6.
Tankless water heaters are about 50 percent more
efficient.
7.
Tankless water heaters save the average
homeowner approximately $165 per year.
Disadvantages of a
Tankless Water Heater
1.
It cannot produce a large amount of hot water at
once.
2.
Turning the hot water on and off repeatedly can
result in a sudden blast of cold water.
3.
The amount of water a tankless unit produces
depends on the temperature desired.
A traditional water heater provides 7.5 to 9.5 gallons of
water per minute, which is typically enough hot water to supply three needs at
one time. A tankless unit produces only 2.5 to 5 gallons, which will supply
only two needs at one time. Further heating water to an increased temperature
of 35 to 45 degrees will allow water to flow faster than heating the water by
77 degrees.
Cost of Tankless Water
Heaters
The typical gas-fired tankless water heater will cost about
$1,500 installed (about twice the cost of a traditional water heater or about
$575 more than a high-efficiency tank model. However, installation will require
replacing ½ inch pipe with ¾ inch pipe throughout your home at a cost of $25 to
$40 per foot. This installation cost will be recovered in reduced operating
cost. Electric tankless units cost far less, typically as little as $400
installed.
·
According to the U.S. Dept. of Energy,
a tankless water heater is more efficient and uses less energy than a
conventional water heater, providing a $25 to $107 in annual savings.
·
If your hot water use is low (less than
41 gallons per day), a tankless water heater will be 24% to 34% more efficient.
·
If your hot water usage is high (about
86 gallons per day), a tankless water heater is 8% to 14% more energy
efficient.
·
Installing an on-demand unit at each
hot water faucet gives an energy savings of 27% to 50%.
