Energy Saving Tankless Water Heaters Supply On-Demand Hot Water
Improved efficent "tankless" water heaters have become very
popular for their capability to heat hot water on demand, saving
money by no longer heating large unused amounts of water.
Instead of holding water in a traditional water tank, they
circulate the cold water through a series of electrically heated
coils that warm the water as it moves pass this heat source.
This newer process of warming water requires more expensive
equipment than the conventional water heater, but this money is
regained in the long term with energy efficiency savings. The
energy efficiency is mainly gained from no longer needing to
heat an entire tank of water. A list of tankless water heaters
can be found at this wate
r heater directory.
Since the tankless water heaters do not store hot water but
rather constantly heat water as it is demanded, they do not run
out of hot water. There is one exception, to this "endless"
supply of heated water. The flow rate is limited. In other words
if you simultaneously use more water than the flow of the water
heater (i.e. 3 people showering at one time) you will receive
unheated water.
Since conventional water heater stores the water together in a
large tank it is able to provide water at a set temperature.
Tankless water heaters differ in this aspect since they are
dependent upon the incoming water temperature and the flow rate.
The incoming water temperature can vary greatly from summer to
winter. The capacity of a tankless water heater is generally
measured by how many temperature degrees it can increase water
temperature by gallons per minute (gpm). Most tankless water
heaters are powered by gas to better handle the heat output and
response time required. These gas powered water heaters require
proper venting, normally more venting than the older,
conventional water heaters required. If you are replacing a
conventional electric water heater tank, you may want to add a
power vent in the side of the wall. This would be the less
costly alternative if there is no existing roof vent. Some of
the smaller and more portable single-fixture units are powered
electrically.