Q:
Under what conditions is the On-Demand Intelligent Recirculation System used?
A:
The On-Demand Intelligent Recirculation System is only used in multiple unit buildings
that have a hot water recirculation line. This line is supplied with hot water by a
boiler or central water heater. Although a smaller kit will be available for single
family residences, we are currently only installing the system in multiple housing units.
Other applications are university residences, military barracks, or any multi-unit building
that has a hot water recirculation line.
Q:
Is there a limit to where the On-Demand Intelligent Recirculation System can be used?
A:
We do not install the On-Demand Intelligent Recirculation System in buildings where the
cold water make-up line is greater than 2 1/2" in diameter. We are currently limiting the
On-Demand system to buildings 7 stories or less. A building must have a hot water
recirculation line to use the system.
Q:
If the recirculation system shuts down, does this impact the time it takes to get hot water?
A:
No. A higher rated pump will be installed if necessary, supplying hot water to the
fixture as usual. In order to allow the pipes to cool down, the circulator pump must
be a high speed pump (at least 3,000 rpm). In buildings with more than 16 units or guest
rooms, a new high speed pump is almost always required.
Q:
How does the On-Demand Intelligent Recirculation System work?
A:
If hot water is not being used, the On-Demand system shuts down the pump. If there is no need
for hot water, the pump remains off. The flow sensor must show activity on the line for the
pump to come on regardless of the temperature of the water in the return line. If there is a
need for hot water, the pump then looks to the temperature sensor to determine if the pipes
are already hot. If the return line is already heated to an acceptable temperature the pump
will not come on. If there is a need for hot water and the pipes have cooled below a preset
acceptable temperature, the high speed pump kicks in and moves hot water out thought the loop
until either the demand ends or the temperature sensor detects hot water at the end of the return line.
In order for the pump to come on there must be a demand and the temperature of the return
line must be lower than a preset acceptable temperature range.
Q:
How does the On-Demand Intelligent Recirculation System save energy?
A:
A recirculation system works 24 hours a day to keep hot water ready for use. This
is very wasteful as hot water is typically only used 15% of the day. When the set
point is reached, lukewarm water in the recirc line is pumped back to the hot water
storage tank and replaced with fresh hot water. This goes on all day and night, even
when hot water is not being used. The On-Demand system shuts down when hot water in
not being used, thus saving on fuel costs to heat the water.
Q:
How much energy does an On-Demand Intelligent Recirculation System save?
A:
The California Energy Commission tests resulted in an average of 37% savings in natural
gas or heating oil required to heat the water. Our lowest result was 19%, but this was
in a university residence where students used hot water at various times of the day and night.
Some tests have resulted in over 50% fuel savings, but results will vary based on hot water
usage.
Q:
Are any environmental benefits realized by using the On-Demand Intelligent Recirculation System?
A:
Yes. Reduced energy consumption directly correlates to reduced emissions. The
reduced energy demand also impacts production requirements for fuel and, although this
may not be good for everyone's pocket book, it is good for the environment. Because the
system also extends equipment life, less used parts are being taken to land fill sites.
Q:
What is the typical ROI for the On-Demand Intelligent Recirculation System?
A:
This is dependent on the number of units and the demographics of hot water use.
In most circumstances, the ROI is under 12 months, and often substantially less than
this. The ROI does not take into consideration additional benefits of extended
equipment life or reduced maintenance costs.
Q:
Does the On-Demand Intelligent Recirculation System have a warranty?
A:
Yes. There is a 3-year warranty on all system components. This does not include a
pump warranty, as this is supplied by the pump manufacturer.
Q:
How is the On-Demand Intelligent Recirculation System installed?
A:
The On-Demand Intelligent Recirculation System must be installed by a licensed plumber.
This is a service that we provide, or you may use your own plumber for this, although
they will have to be trained on installation procedures.
Q:
How long does it take to install the On-Demand Intelligent Recirculation System?
A:
It typically takes 2 hours to install the On-Demand Intelligent Recirculation System
by a trained plumber. It may take up to 3 hours for the first installation.
Q:
What is required before installation of the On-Demand Intelligent Recirculation System?
A:
The building water supply must be shut off and the pipes drained before the
On-Demand Intelligent Recirculation System can be installed. This should be arranged
before the plumber gets to the site in order to reduce the time of installation.
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