Direct connection for fan coils in heating and cooling systems
HerzCON from HERZ Armaturen is a preassembled connection unit for fan coil units. It combines pressure-independent control, balancing, isolation, filtration, flushing and draining in one compact unit.
HerzCON is a direct connection unit for fan coils in heating and cooling systems. Control, balancing, isolation, filtration, flushing and draining are combined in one unit that is fully assembled and tested in the factory.
At its core is the HERZ 4006 SMART pressure-independent balancing and control valve (PIBCV). Multifunctional ball valves, a strainer with drain valve and a flushing bypass allow the circuit to be filled, drained, flushed and cleaned through the unit.
Components
What is inside the unit
Exploded view of the HerzCON unit and insulation box.
4006 SMART PIBCV
Pressure-independent balancing and control valve. Keeps the flow constant when the system pressure changes; flow is preset in percent.
Multifunctional ball valves
Supply and return isolation with red and blue handles. The full-bore T-port allows draining or filling of the system.
Strainer with drain valve
HERZ strainer with 2512 blow-down drain valve, for flushing and cleaning the strainer basket in place.
Flushing bypass
Bypass for flushing the pipework with the fan coil isolated, as recommended by BSRIA BG29/2011.
Venting valve and test points
Venting valve and 0284 test points for flow and differential-pressure measurement.
Insulation box
For DN15 to DN25, standard or FR1 version. Vapour-impermeable and supplied vapour sealed for chilled water.
Sizes
Sizes and flow data
Size
Kvs normal m³/h
Kvs bypass m³/h
Flow @100% l/h
Flow @100% l/s
Max. Δp bar
DN15 LF
0.20
4.8
120
0.033
4
DN15 MF
0.34
4.8
190
0.053
4
DN15 SF
1.65
4.8
800
0.222
6
DN15 HF
2.54
4.8
1200
0.333
6
DN20 SF
2.46
5.4
1200
0.333
6
DN20 HF
3.33
5.4
2000
0.556
6
DN25
2.75
10
1900
0.528
4
DN32
4.57
14.2
2500
0.694
4
Values from the HERZ HerzCON datasheet. Recommended presetting: 20% to 80% of nominal flow. Pipe centres: 65 mm (DN15, DN20), 90 mm (DN25), 100 mm (DN32).
Operating Modes
Four operating modes in one unit
Normal operation
Bypass and strainer drain closed; the PIBCV is preset to the design flow.
Bypass flushing
Bypass open and PIBCV closed, so the pipework is flushed without passing through the fan coil.
Forward flushing
Supply ball valve and strainer drain open; flushing through the strainer to atmosphere.
Backflushing
Strainer drain and PIBCV open; flushing through the ball valve, PIBCV, fan coil and strainer.
Applications
Where HerzCON is used
HerzCON units at each fan coil on heating and cooling risers.
Fan coil units
Direct connection of fan coils with control, balancing and flushing in one unit.
Chilled water circuits
Vapour-sealed insulation box for cooling duty, DN15 to DN25.
Heating circuits
Hot water operation up to 130 °C.
Hydronic networks
Commercial, institutional and residential buildings.
Features
Technical data
Pressure & temperature
Max. operating pressure: 25 bar.
Operating temperature: -20 °C to 130 °C.
Max. differential pressure: 4 or 6 bar, depending on size.
Valve lift: 4 mm.
Control & balancing
Flow preset in percent on the valve; recommended 20% to 80% of nominal flow.
Actuators: 7708 two-point, 7711 two-point or pulse, 7990 continuous control.
On/off or modulating 0–10 V DC actuators; BMS integration possible.
Test points P1–P2 for flow; DN15 SF/HF and DN20 SF/HF add P3 for minimum Δp.
Materials & media
Body: dezincification-resistant (DZR) brass.
Membranes and O-rings: EPDM.
Water to ÖNORM H 5195-1; water quality to ÖNORM H 5195 and VDI 2035.
Ethylene or propylene glycol, 25 to 50 vol.%. Mineral-oil lubricants can damage EPDM seals.
Insulation box fire behaviour
Standard box: Class E (DIN EN ISO 11925-2), B2 (DIN 4102-1).
FR1 box: Classes B, C, D (DIN EN ISO 11925-2), B1 (DIN 4102-1).
Benefits
Why choose HerzCON
One unit, fewer joints. Assembled and tested in the factory, so fewer fittings are made on site.
Stable flow at each fan coil. Pressure-independent control keeps the design flow when the system pressure changes.
Simpler commissioning. Percent presetting and test points make flow setting and checking quicker.
Clean circuits. The flushing bypass and in-place strainer cleaning keep dirt out of the fan coil.
Heating and chilled water. The vapour-sealed insulation box makes the same unit suitable for cooling.
Easy maintenance. Isolation, draining and strainer cleaning without removing the unit.
Need support with HerzCON?
Share the fan coil flow rate, pipe size and whether the circuit is heating or chilled water, and our MEP team will support you with the suitable HerzCON size.
