Dunkirk Helix VLT Vertical Laser Tube, Wall Hung Modulating Condensing Boiler - Manual (Page 4)

4
BACKGROUND
Application Concept
I. Kit is for applications that employ ECR Stainless Condensing
boiler to work with an additional heating device.
II. If the additional heating device can constantly supply
hot water at 165°F or HIGHER, it is considered a HIGH
Temperature Heating Device. Follow installation procedure
in SECTION A. Following are common High Temperature
Heating Devices
• Indoor wood water boiler
• Outdoor wood water boiler
• Electric boiler
III. If Additional Heating Device only constantly supplies
hot water at LESS THAN 165°F, it is considered a LOW
Temperature Heating Device. Follow installation procedure
in SECTION B. Following are common Low Temperature
Heating Devices.
• Geothermal hot water heating device
• Solar water heating device
• Electric hot water heat pump
IV. Heating capacity of the additional heating device will be fully
utilized when available.
V. Stainless Condensing boiler will fire only when the additional
heating device cannot satisfy heat demand.
Water Flow Arrangement
VI. The piping connection establishes flow where water flows
through the two heating devices (Stainless Condensing boiler
and Additional Heating Device) in a sequential manner. The
goal is to make the two heating units work together at the
maximum possible system heating efficiency.
If the additional heating device is a HIGH temperature device,
return water goes into the Stainless Condensing boiler first.
The purpose is to have the stainless condensing boiler work in
the condensing regime as much as possible. SECTION A.
If the additional heating device is a LOW temperature heating
device, return water flows into additional heating device first
to fully utilize the capacity of the additional heating device.
SECTION B.
VII. The water flow arrangement takes advantage of the Stainless
Steel Condensing boiler's built in primary loop and internal
water pump.
Water Temperature Control
VIII. The system is configured so the Stainless Condensing boiler
control system will modulate its firing rate to sustain Supply
Water Temperature at the setting point in all conditions.
• When Additional Heating Device is supplying heat at
its full capacity.
• When Additional Heating Device is supplying heat at
reduced capacity.
• When Additional Heating Device is not supplying
heat.
Heating Priority Establishment
IX. The two heating units are configured to supply heat in the
following manner.
• When the Additional Heating Device alone CANNOT
maintain supply water temperature at or higher
than the temperature set point of the Stainless
Condensing boiler, the Stainless Condensing boiler
will fire.
• When the Additional Heating Device alone CAN
maintain a supply water temperature higher
than the temperature set point of the Stainless
Condensing boiler, the Stainless Condensing boiler
will NOT fire.
BACKGROUND