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WARNING
Water quality has a significant
impact on the lifetime and
performance of an IBC Boiler /
Water Heater heat exchanger.
Improperly prepared water in
a heating circuit may cause
damage to the heat exchanger
through corrosion or fouling.
Repeated or uncontrolled
water fills will increase the
potential for damage.
High levels of dissolved
solids or minerals may
precipitate out of the fluid
onto the hottest part of the
heat exchanger, impairing
heat transfer and resulting in
overheating and premature
failure. The amount of solids
that may form on the heat
exchanger will depend on
the degree of hardness and
the total water volume in the
system. A high water volume
system with a low hardness
count may cause as much
damage as a system with less
volume and higher hardness,
so it is recommended to treat
water so as to remove all
dissolved solids. Other water
chemistry allowable limits are
as follows:
•
Acidity pH is to be between
6.5 and 8.5
•
Chloride is to be less than
125 mg/l
•
Iron is to be less than 0.3
mg/l
•
Cu less than 0.1 mg/l
•
Conductivity is to be less
than 400μS/cm (at 25°C)
•
Hardness is to be 7 Grains
or less
IMPORTANT: Ensure that
these limits are acceptable
for the other water-side
components in the system.
INSTALLATION
DC SERIES BOILERS / WATER HEATERS DC 15-95, DC 15-96, DC 20-125, DC 33-160
Figure 25: Basic Primary/Secondary piping with closely-spaced tees concept – concept
drawing. This drawing is only a simple schematic guide.
We recommend water flow after burner shutdown to utilize legacy heat – this is
significant due to the mass of the heat exchanger. The boiler / water heater pump
is under the control of the boiler / water heater to allow pump purge after burner
shut-down. Default software values will run the boiler's pump for 1 minute after
the burner shuts down.
Schematics for several piping layouts are provided herein, and additional
drawings are available at www.ibcboiler.com. Installers shall conform the piping
design to one of the provided configurations to simplify the control application,
promote good loads and flow management.
Propylene glycol solution is commonly used in a closed loop where freeze
protection is required. Its density is lower than that of water, resulting in
lower thermal performance at a given flow and pressure. As a rule of thumb,
a 50%:50% solution of propylene glycol and water will require an increased
system circulation rate (gpm up 10%), and system head (up 20%) to provide
performance equivalent to straight water.
The DC series modulating boilers / water heaters offer exceptional matching
of heat generation to radiation. The low minimum firing is better suited to low
thermal loads presented in a typical multi-zoned radiation system. However,
where individual zones in a heating system have loads under 10,000 Btu/hr, the
system will still benefit through use of a buffer tank to ensure a controlled supply
temperature, and to prevent short cycling. Buffering should be added on the
secondary piping of the relevant load, to avoid bulking up the thermal mass of the
primary piping circuit (and potentially lengthen the duration of the transition from
hot to cool loads).
DC modulating series boilers / water heaters can be connected directly to a floor
of non-oxygen barrier polybutylene material (PB tubing). The internal boiler /
water heater piping, and connections are all non-ferrous with the exception of the
corrosion resistant epoxy coated cast iron pump. For maintenance of warranty
on such systems, we require evidence of a thorough flushing of all loops, plus
installation of a dirt separator or side stream filter. A separator/filter maintenance
routine shall be carried out after the retrofit, with filter clearing after the 1st day,
1st week, month and annually thereafter. The installer must insure that all
external piping components and pumps are non-ferrous when connecting
the boiler / water heater to a system with non-oxygen barrier tubing.
1-23
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