Brochure

Functions
MAGNA3
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8. Functions
System application
Heating systems
Fig. 20 Functional drawing of a heating system in a commercial building
Main pumps
Due to variations in the heat demand and water flow
rate, we always recommend to use speed-controlled
MAGNA3 pumps in a heating system, either
single-head pumps connected in parallel or twin-head
pumps. Single-head pumps connected in parallel have
several advantages. In alternating operation, each
pump is sized for 100 % flow. In this operating mode,
the second pump functions as back-up for higher
reliability. As the pumps alternate, an equal number of
operating hours is ensured. Cascade operation of
pumps connected in parallel meets demands in
high-flow systems with low differential temperature
(Δt), and 50 % back-up is ensured at the same time.
The twin-head pump saves installation time and costs.
By speed-controlling all pumps, it is possible to obtain
maximum energy saving as the pumps will run at their
best efficiency point (BEP).
In a variable-flow system, we recommend to control
main pumps in proportional pressure or AUTO
ADAPT
mode with a differential pressure sensor in the flow
pipe with the lowest pressure. This ensures maximum
energy saving.
By using the FLOW
ADAPT
function to ensure correct
balancing of the system, the need for pump throttling
valves can be reduced significantly.
The built-in heat energy meter allows monitoring of the
heat energy consumption in the system for pure
optimisation purposes.
Air handler heating coils
The performance of heating surfaces is controlled by
the heating-water temperature and flow. For this
purpose, we recommend to install variable-flow mixing
loops at the heating surfaces. A speed-controlled
mixing-loop pump is ideal for adaptation to the varying
load in a heating surface. In this case, the MAGNA3
will have full authority, making external pump throttling
valves superfluous.
Domestic hot water
For domestic hot water circulation, the constant
temperature control mode will ensure a constant
temperature in the recirculation pipe, without the use
of separate thermostatic valves, thus obtaining the
maximum comfort.
TM05 2155 1312
M M
M
M
M
Pos. Description
Main pumps
A Boiler
Air handler heating coils
Domestic hot water
B Hot water circulation
C Cold water
Mixing loops
D Radiators
E Fan coils
F Underfloor heating
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