CIRCULATION SYSTEM
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CIRCULATION SYSTEM: HEATING & AIR CONDITIONING
Wet rotor circulators for heating and air conditioning system
EVOSTA
(only heating)
EVOTRON
APPLICATIONS:
 Circulate water in a closed circuit in both heating
and air conditioning system
 Used also in solar heating circuits
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CIRCULATION SYSTEM: HEATING & AIR CONDITIONING
Wet rotor circulators for heating and air conditioning system
EVOSTA
EVOTRON
EVOPLUS SMALL
VS
(only heating)
Main features:
 Flow rates from 1 to 9,6 m3/h and with maximum differential pressure head of 11m,
depending of the model for domestic and residential application.
 Temperature range from -10°C to +110°C
 The pumped liquid must be clean, free of oily substances and chemically neutral.
 Motor casing in die cast aluminum impeller in engineering polymer ULTEM
 Threaded or flanged unions depending on the model
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MAIN COMPONENTS OF A HEATING SYSTEM
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MAIN COMPONENTS OF A HEATING SYSTEM
 Generation:
Converting the energy carrier
 Accumulation:
Temporal decoupling of generation and use of heat
 Distribution:
Transport of heat in the building
 Emission:
Heat transfer in environment
 Regulation:
Decide when, where and how much heat issue in environment
It has nothing to do with the regulation of the generator
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HYDRAULIC CIRCUIT
 To transport the heat it’s necessary to spin the water along delivery
and return
BOILER
 For each lap, the water carries a quantity of heat proportional to the
difference between the supply temperature and the return
temperature
 If the temperature difference between supply and return is high
enough to run a little water
BOILER
 To spin the water in a circuit must be a push (pressure) sufficient to
overcome the resistance (pressure losses of pipes and devices)
 To adjust the power output of the system we will have to adjust the
water flow and water temperatures or heat exchange to the radiators
BOILER
(fan)
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HYDRAULIC CIRCUIT
Pressure
Pressure losses
Pressure losses
Pressure losses
Pressure losses
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SYSTEM FLOW RATE CALCULATION
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SYSTEM FLOW RATE CALCULATION
𝑷 ∙ 𝟎, 𝟖𝟔
𝑸=
∆𝑻
 Q : water flow rate [m3/h]
 P : demanding heat [kW]
 0,86 : factor for conversion from kW to kcal/h
 ΔT : temperature difference between delivery and return [°C]
Temperature delta
Legislation stipulates that for every building it has to be assigned
a “heat-loss factor”; the law establishes also a maximum room
temperature of 20°C.
To ensure the room temperature is kept at 20°C, a balance must
be established between the “heat-loss factor” and the building
overall heat-drop.
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SYSTEM HEAD CALCULATION
The system head is calculated by adding together the localized friction loss in
the heating system.
Example:
H = Hed ∙ K
•
Hed = building height of 9 m
•
K = let’s assume this is 25% - 30% of the
building’s height
1.
H = 9 x 0.30 = 2.7 m
2.
H = 9 x 0.25 = 2.25 m
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SYSTEM HEAD CALCULATION
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THE HYDRAULIC PROBLEM
When the flow rate decreases, the pressure losses decrease dramatically
Flow rate = 1000 l/h
Pressure losses = 30 mm.w.c.
Flow rate = 500 l/h
Pressure losses = 7,5 mm.w.c.
The pressure losses depend on the square of the flow
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MAIN REGULATION MODES WITH ELECTRONIC CIRCULATORS
CONSTANT
differential pressure ΔP-c
PROPORTIONAL
differential pressure ΔP-c
CONSTANT
curve speed
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CONSTANT DIFFERENTIAL PRESSURE
Q = Variable
H = Constant
This control mode is particularly useful in:
 heating and conditioning systems with low pressure loss
 two-pipe central heating systems with thermostatic valves and head ≤ 2 m
 single-pipe central heating systems with thermostatic valves
 systems with natural circulation
 installations having primary circuit pumps with low pressure loss
 sanitary recirculation systems with thermostatic valves
Set by scrolling through the Evoplus menu or with the external signal (0-10V or PWM)*
*MULTIFUNCTION module requested for this application on EVOPLUS SMALL
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PROPOTIONAL DIFFERENTIAL PRESSURE
Q = Variable
H = Variable
This control mode is particularly useful in:
 heating and air conditioning systems with high pressure loss
 double-pipes central heating systems with thermostatic valves and head ≥ 4 m
 heating systems with secondary differential pressure regulators
 installations having primary circuit pumps with high pressure loss
 sanitary recirculation systems with thermostatic valves
Set by scrolling through the Evoplus menu or with the external signal (0-10V or PWM)*
*MULTIFUNCTION module requested for this application on EVOPLUS SMALL
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PROPOTIONAL DIFFERENTIAL PRESSURE
Q = Variable
H = Variable
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CONSTANT CURVE
H
Curve limit
Constant speed
The operating curve can be adjusted manually
Q
setting the percentage reduction factor. The value
100% indicates the “Curve Limit” .
This control mode is particularly useful in:
 heating and air-conditioning systems with constant flow
Set by scrolling through the Evoplus menu or with the external signal (0-10V or PWM)*
*MULTIFUNCTION module requested for this application on EVOPLUS SMALL
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CONSTANT CURVE
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CONSTANT DIFFERENTIAL PRESSURE
DIFFERENTIAL PRESSURE CONTROL MODE
ELIMINATED THE
NOISE THANKS TO
AUTOMATIC
ADJUSTMENT OF THE
CIRCULATION
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PROPOTIONAL DIFFERENTIAL PRESSURE
ELIMINATED THE
NOISE THANKS TO
AUTOMATIC
ADJUSTMENT OF THE
CIRCULATION
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SYSTEM DESIGN EXAMPLES 1
SINGLE-PIPE HEATING SYSTEM (RADIATORS IN SERIES)
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SYSTEM DESIGN EXAMPLES 2
TWO-PIPE HEATING SYSTEM (RADIATORS IN PARALLEL)
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SYSTEM DESIGN EXAMPLES 3
UNDER-FLOOR HEATING SYSTEM
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ELECTRONIC CIRCULATORS MODELS
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
Flow rate → 0,6 – 3,5 m3/h

Head max → 7 m

Flow rate → 0,6 – 4,2 m3/h

Head max → 4 – 8 m

Flow rate → 4,2 – 9,6 m3/h

Head max → 4 – 11 m
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ELECTRONIC CIRCULATORS MODELS
TWIN
TWIN
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
Flow rate → 4,2 – 72 m3/h

Head max → 4 – 18 m

Flow rate → 2,4 – 9,6 m3/h

Head max → 4 – 11 m

Flow rate → 4,2 – 72 m3/h

Head max → 4 – 18 m
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CIRCULATORS MODELS FOR SANITARY WATER
VS
SAN
SAN
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
Flow rate → 0,6 – 5,4 m3/h

Head max → 0,8 – 6,5 m

Flow rate → 0,6 – 4,2 m3/h

Head max → 4 – 8 m

Flow rate → 1,8 – 42 m3/h

Head max → 4 – 15 m
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FLOW RATE CALCULATION
Example:
Assume you need a circulator for a standard heating system.
We know that the boiler heating capacity is 10000 kcal/h and that system pressure drop is about
4 m.
Data :
System pressure drop = 4 m
Boiler capacity = 10000 kcal/h
Considering a temperature difference between delivery and
return = 20°C
1. Apply the formula for the flow rate:
𝑄
𝑙
=
𝑠
𝑘𝑐𝑎𝑙
𝑘𝑐𝑎𝑙
10000
𝑙
𝑚3
ℎ
ℎ
=
= 0,41
⇒ 0,5
∆𝑇 [°𝐶] ∙ 3600
20 °𝐶 ∙ 3600
𝑠
ℎ
𝐵𝑜𝑖𝑙𝑒𝑟 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦
Suitable circulator = EVOTRON 40/130 or
EVOSTA 40/70
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IMPORTANT INFORMATION FOR THE INSTALLATION
We recommend:
 Install check valves in both the suction line and the delivery line
 The terminal box must never be below the pump
 30% maximum glycol contents
 In case of heat insulation, ensure the motor casing condensate discharge
nozzles are not clogged
 The circulator is maintenance free
 The unit can be supplied complete with unions and other accessories
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