There are basically three common design layouts
used when plumbing is installed into new homes. The most
popular is referred to as Standard Plumbing. The
second most common is known as Dedicated re-circulating
line, which requires an additional line for the hot water
to return to the water heater. The third most common plumbing
scheme is called Manifold where there are dedicated
hot water lines independently running to each fixture directly
from a manifold block off the water heater.
On the other hand, Structured
Plumbing is a new plumbing layout that is more
effective than the other three designs. Structured Plumbing
saves both water and energy, and will save between 15% to
50% of the energy used in the three common plumbing layouts.
Standard Plumbing
The majority
of homes are
plumbed in this
manner. Depending
on where the
fixtures
are located,
the hot water
line runs as
a main line then
branches to the
fixtures.
In most cases,
the branches
are short and
the main hot
water line is
long. With
piping and
labor being so
expensive, the
plumbing design
is driven by
economics
and is not
always the best
for the homeowner.
The inconvenience
of waiting for
hot water
becomes an
issue, and costly
waste of water,
sewage, and energy
results. The
Metlund (S-Series)
D'MAND System is easily installed to work
with homes with standard plumbing, making
them effective for saving both water and
energy.
Dedicated re-circulating Line
re-circulating systems are becoming
more popular due to the population's increasing interest in
saving water and adding convenience to their lives.
Re-circulation systems function by running 24 hours per day;
or running on a timer; or a thermostat; or running on both
a timer and a thermostat.
This
method of re-circulating hot water requires
specially designed plumbing where the
hot water pipe from your water heater
is plumbed to each fixture in a loop fashion,
and then continues back to the water heater
through a third line (return line). A
small pump re-circulates the hot water
in a continuing loop, only shutting off
with a timer or thermostat.
This method can be very costly to operate. Although
it saves water, the energy costs can be very high. While the
pump cost can be as low as $25 per year to operate, the cost
of the operation of the water heater can be very high. Circulating
hot water slowly means that the water will re-enter the water
heater at a lower temperature. The water heater will constantly
cycle on and off during this re-circulation process as it
attempts to bring the water in the water heater up to its
original temperature. Since the average family uses hot water
about 15 times per day, re-circulating hot water can cost
as high as $100 month depending on whether your water heater
is gas, electric or propane powered.
Two additional potential problems with re-circulating hot
water are the erosion of the hot water line due to the increased
volume of water flowing through it, and the inconvenience
of not having hot water if the timer is not operating properly.
It may be necessary to reset the timer after an extended power
outage.
Manifold Block Hot Water Systems
Manifold Block Hot Water Systems are designed to have the
hot water enter a block near the water heater. The block,
similar to a small holding tank, has many small lines going
in various directions to each hot water fixture in the home.
For example, bathroom sinks and showers would be on their
own hot water line from the water heater.
The theory is that smaller lines move water more quickly
thereby shortening the wait for hot water and consequently
using less water to get hot water. The reality is that in
most cases, there is a wait for hot water at every
fixture, it is not very convenient, and people use more water.
They save neither water nor energy.
Learn more about Structured Plumbing...
|