System 1: Single Boiler With Outdoor Reset, Multiple Heating Zones With Zone Pumps And Dhw - Buderus Logamax plus GB162 Applications Manual

GB162 Applications Manual
3.1 System 1: Single boiler with outdoor reset, multiple heating zones
with zone pumps and DHW
Summary:
Single boiler supplying multiple heating zones equipped
with 3rd party thermostats and zone pumps. This system is
recommended if pressure drops in individual zones are too
great to be served by a single system pump (see system 2).
• High efficiency outdoor reset controlled system based on
heat loss of the structure
• Outdoor reset for system supply water temperature
• Zone pumps are controlled by 3rd party relay panel and
individual room thermostats
• Optional DHW tank loading with or without priority
In detail:
The AM10 outdoor reset controller receives a heat demand
from the zone thermostats via a closed contact and computes
the system supply water temperature based on information from
the outdoor sensor and the heating curve.
Applications include multiple zones at the same temperature,
or zones at different temperatures if thermostatic or externally
controlled motorized mixing valves are used.
The AM10 provides warm weather shutdown.
The modulating boiler strives to run at low fire for the longest
time possible where efficiency is at its highest.
DHW is heated based on the signal from the DHW tank sensor
FW. DHW is generated in parallel with space heating if both are
calling simultaneously. For faster DHW recovery, install a relay
that disables zone circulators while the tank loading pump is
activated. Alternatively a zone relay panel with DHW priority can
also be used.
The low loss header decouples the boiler loop from the system
loop.
Required components:
• GB162 boiler
• AM10 controller (incl. with GB162 single boiler LLH)
• PH zone circulators
• PS DHW tank loading circulator
• ECM pumps (low energy or constant pressure pumps) are
recommended for constant flow rate and additional energy
savings.
• DHW tank
• Multi zone pump relay panel with/without DHW priority
• PS DHW tank loading circulator
• Zone thermostat per room/zone
Logamax plus GB162 applications manual | 03.2013
Additional instructions:
See manufacturer's installation and operating instructions for
details on 3rd party components.
The system shown generates space heating and DHW
in parallel, which requires the boiler to be sized accordingly.
If the DHW sensor in the tank reports a call for DHW, the boiler
will ramp up the supply temperature according to the DHW
setting overriding the outdoor reset heating curve.
If there is a simultaneous call for space heating, the higher
water temperature will lead to the zones being satisfied sooner
than on outdoor reset alone. To prevent overheating of zones
(e.g. radiant flooring) install thermostatic mixers or high limits on
the relevant zones.
For DHW priority, see Appendix 3.
Technical specifi cations are subject to change without prior notice
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