Am10 Outdoor Reset Modulating Boiler Control - Buderus Logamax plus GB162 Applications Manual

1 0 |

2.4 AM10 Outdoor Reset Modulating Boiler Control

Product Description
The AM10 is a modulating outdoor reset control for Buderus
boilers equipped with the EMS bus. It sets the supply water
temperature based on outdoor temperature. The boiler fires,
runs and modulates based on the information received from the
AM10, and the delta T between supply and return.
An ON/OFF signal from a third party room thermostat or
zone controller (not included) is used to communicate a heat
demand. The AM10 offers warm weather shutdown (WWSD)
when the outdoor temperature rises above a custom setable
temperature (default: 70°F (21°C)).
To control and stage multiple boilers, combine the AM10 with an
MCM10 cascade module.
Outdoor reset
Outdoor reset is a way to economically control space heating
based on the outdoor temperature. It functions based on the
fact that the colder the weather the greater the heat loss of a
structure, and the higher the supply water temperature needed
to heat the house. On a warmer day with smaller heat loss a
lower water temperature will be able to heat the house. This has
several advantages:
1. Save fuel by running the boiler at lower temperatures
which reduces the heat going up the chimney.
2. Lower water temperatures allow taking advantage of the
energy trapped in the flue gases (latent heat) in a
condensing appliance.
3. Added comfort because temperature changes are not felt
with lower water temperatures running constantly.
To achieve these goals the reset curve must be properly
adjusted to match the application and the heat loss of
the structure. The reset curve tells the boiler what water
temperature is needed at a certain outdoor temperature.
Outdoor reset is the preferred control when using multiple
zones, as the boiler supply water temperature is not dictated by
a master or largest zone, but solely based on the heat loss of
the structure.
Technical specifi cations are subject to change without prior notice
GB162 Applications Manual
Fig. 6 AM10 Modulating Control
Logamax plus GB162 applications manual | 03.2013