A packaged heat exchange unit must match source temperature, secondary duty, pump head and pressure-maintenance strategy; wrong configuration shifts problems from the exchanger to the skid.
YONGFAN ZS and ZW skids integrate plate heat exchangers, circulating pumps (2–3 sets), automated make-up (VFD or FIYO expansion device), valves, sensors, and PLC control cabinets for 3,000–300,000 m² heating areas.
Under-head pumps fail to circulate design flow across the plate pack; over-head pumps waste energy through valve throttling and cavitation.
Choosing variable-frequency make-up (ZS) vs expansion device (ZW) from price alone causes pressure cycling and relief valve lifting.
A 45/55 °C floor heating system (10 K ΔT) requires 2.5× more water flow than a 60/85 °C radiator loop (25 K ΔT) for the same MW load.
Sizing from catalog m² (based on 70 W/m²) without calculating actual building insulation and climate heat loss causes winter freeze-outs.
Steam basis: saturated steam ≤0.4 MPa; area based on 70 W/m² building load.
| Capacity Class | Heating Area Basis | Secondary Water Output (t/h) | Steam Consumption (t/h) |
|---|---|---|---|
| 0.21 MW | 3,000 m² | 7 | 0.31 |
| 0.35 MW | 5,000 m² | 12 | 0.52 |
| 0.70 MW | 10,000 m² | 24 | 1.04 |
| 1.05 MW | 15,000 m² | 36 | 1.57 |
| 1.40 MW | 20,000 m² | 48 | 2.09 |
| 2.10 MW | 30,000 m² | 72 | 3.13 |
| 3.50 MW | 50,000 m² | 120 | 5.22 |
| 5.60 MW | 80,000 m² | 193 | 8.35 |
| 7.00 MW | 100,000 m² | 241 | 10.40 |
| 9.80 MW | 140,000 m² | 337 | 14.60 |
| 14.00 MW | 200,000 m² | 482 | 20.90 |
| 21.00 MW | 300,000 m² | 722 | 31.30 |
Steam basis: saturated steam ≤0.4 MPa; smaller 10 K ΔT requires significantly higher circulation flow.
| Capacity Class | Heating Area Basis | Secondary Water Output (t/h) | Steam Consumption (t/h) |
|---|---|---|---|
| 0.21 MW | 3,000 m² | 18 | 0.31 |
| 0.35 MW | 5,000 m² | 30 | 0.52 |
| 0.70 MW | 10,000 m² | 60 | 1.04 |
| 1.05 MW | 15,000 m² | 90 | 1.57 |
| 1.40 MW | 20,000 m² | 120 | 2.09 |
| 2.10 MW | 30,000 m² | 181 | 3.13 |
| 3.50 MW | 50,000 m² | 301 | 5.22 |
| 5.60 MW | 80,000 m² | 482 | 8.35 |
| 7.00 MW | 100,000 m² | 602 | 10.40 |
| 9.80 MW | 140,000 m² | 843 | 14.60 |
| 14.00 MW | 200,000 m² | 1,204 | 20.90 |
| 21.00 MW | 300,000 m² | 1,806 | 31.30 |
| Series | Make-Up Method | Primary Heat Source | Documented Secondary Program | Published Capacity |
|---|---|---|---|---|
| ZSNB | Variable-frequency make-up pumps | Steam (≤0.4 MPa) or Hot Water (95/70 °C) | 60/85 °C (Radiator) | 0.21 – 21 MW |
| ZWNB | FIYO-series expansion device | Steam (≤0.4 MPa) or Hot Water (95/70 °C) | 60/85 °C (Radiator) | 0.21 – 21 MW |
| ZSK(D)B | Variable-frequency make-up pumps | Steam (≤0.4 MPa) or Hot Water (95/70 °C) | 45/55 °C (Floor / A/C) | 0.21 – 21 MW |
| ZWK(D)B | FIYO-series expansion device | Steam (≤0.4 MPa) or Hot Water (95/70 °C) | 45/55 °C (Floor / A/C) | 0.21 – 21 MW |
Steam pressure (MPa) or primary water 95/70 °C parameters.
Specify 60/85 °C (radiator) or 45/55 °C (floor/AC heating).
Calculated building heat loss in kW or MW (avoid generic m²).
Select ZS (VFD make-up pump) or ZW (FIYO expansion device).
YONGFAN engineers will calculate circulation flow, size pump heads, configure make-up equipment, and provide 3D CAD skid layouts.
The plate heat exchanger receives a 1.25× design pressure hydrostatic test before integration into the skid.
Assembled primary and secondary pipework, valves, and headers undergo complete pressure and leak testing.
Pump sequencing, VFD frequency control, pressure transmitters, and alarm logic are 100% bench-tested.
Circulating and make-up pumps are checked against rated flow, static head, and motor current draw.
Documented from 0.21 to 21 MW per packaged unit, serving 3,000 to 300,000 m² heating areas on a 70 W/m² basis.
ZS uses variable-frequency make-up pumps for active pressure holding. ZW uses a FIYO pressure-stabilizing expansion device.
NB is the radiator-heating family with 60/85 °C water. K(D)B is the air-conditioning/floor-heating family with 45/55 °C water.
Yes. Documented steam-to-water versions use saturated steam up to 0.4 MPa, equipped with steam control valves and traps.
Because the secondary temperature rise is only 10 K (vs 25 K on radiators). 2.5× more water must circulate to move the same MW heat load.
Yes. The gasketed plate pack can be opened and cleaned on the skid without dismantling surrounding pump headers.
Catalog m² assumes 70 W/m². Actual selections must use calculated building envelope heat loss.
When peak domestic hot water buffering is required, select Storage Heat Exchangers.
Packaged units provide hydraulic isolation. For direct high/low zone connection without PHE, see Direct-Mixing Units.
Steam-to-water skids require condensate traps and steam valves; they cannot be casually switched to water without repiping.
Send your primary heat source parameters, secondary loop temperatures, heating load, and preferred make-up strategy. YONGFAN engineers will provide skid sizing calculations and 3D GA drawings.
