This FAQ answers common technical and commercial questions about selecting YONGFAN HVAC components, reviewing compliance documents, and preparing project enquiries.
Explore direct engineering answers covering airside filtration (Primary, Medium, HEPA/ULPA, FFU), chemical/gas-phase adsorption, ventilation fans (Axial, Mixed-Flow, Centrifugal, Tunnel Jet), dampers and VAV distribution, heat exchange and hydronic plant skids, control valves, lead times, and customization.
This website focuses on HVAC system components and auxiliary equipment rather than complete central plant. Core scope includes air filtration, ventilation fans, fan boxes, dampers/VAV, chemical filtration, heat exchangers, hydronic booster skids, water treatment, and control valves. Major chillers and AHUs are represented elsewhere in the wider portfolio.
Start from the physical problem: airflow against resistance → fans/fan boxes; particle removal → staged filtration; corrosive/toxic gases → chemical filtration; heat transfer → heat exchangers; water pressure/flow → hydronic skids/valves. Sizing follows duty.
Usually not. A fan cannot be selected from airflow alone because static pressure determines operating point; a filter needs airflow, depth, and clean/dirty ΔP; a heat exchanger needs 4 terminal temperatures; a valve needs flow and differential pressure.
Yes. YONGFAN application engineers review airflow/pressure, filtration stages, gas contaminants, temperature programs, and hydronic conditions. However, project-specific selection does not replace the consultant’s overall building or process system design.
Primary filters capture coarse dust and protect coils; medium filters (F5–F9) capture fine particles and protect terminal stages; HEPA/ULPA filters (H13–U17) capture sub-micron particles at MPPS for cleanrooms and surgical suites.
No. Higher efficiency increases resistance, fan power, and cost. Sizing should meet the required cleanliness class while optimizing system pressure drop and extending final filter lifespan.
Do not make direct conversions by assumption. ISO 16890 uses an ePM spectrum (ePM1, ePM2.5, ePM10). Request the model’s ISO 16890 test report to confirm exact compliance.
No. Cleanroom ISO 14644 classification requires adequate air changes, laminar airflow velocity, leak-free terminal housings, positive pressure cascades, and verified commissioning.
GCDZ is the HEPA filter element; GFK is a passive ceiling terminal; GCFK is a shallow 150 mm passive terminal; FFU integrates an autonomous fan with the HEPA filter.
No. HEPA captures physical particles. Molecular gases (H2S, SO2, VOCs, NH3) require activated-carbon or chemical chemisorption media.
Start with the target contaminant species, concentration (ppm/ppb), airflow, temperature, relative humidity, and contact residence time rather than filter shape alone.
The HT Activated Carbon Canister family is the clearest refillable route. Cylindrical canisters lock into holding frames and can be refilled with bulk media, reducing discarded hardware.
Not reliably. Chemical media can reach chemical saturation and contaminant breakthrough without a measurable increase in pressure drop. Replacement must follow operating hours or gas sampling.
PSA/PSA-PG treats fresh makeup air; DBS provides positive-pressure protected-room air; CA handles indoor recirculation; WGP treats industrial process exhaust before outdoor discharge.
No. ANSI/ISA-71.04 Class G1 is an environmental corrosion-severity target (<300 Å/30 days copper corrosion) for electronic rooms, not a simple single-pass percentage rating.
Follow: airflow → static/total pressure → handled air → mounting orientation → temperature/smoke duty → Ex class → acoustics → electrical supply. Never size by diameter or motor kW alone.
Provide the pressure basis used in your system calculation. Comparing two Pa figures without knowing static vs total pressure can lead to dangerous undersizing.
Axial (DTF/DTXF) moves high flow at low/medium pressure; Mixed-Flow (SWF) provides in-line tubular mounting with higher pressure capability; Centrifugal (4-72) overcomes high duct resistance.
Smoke-exhaust fans feature fire-rated builds certified for 280 °C / 30-minute emergency operation under building fire codes (GB 50016), with isolated motor cooling and fire wiring.
No. Explosion protection prevents ignition in classified atmospheres (GB 3836); fire ratings cover high-temperature endurance. Each requirement needs its dedicated certified build.
Tunnel jet fans impart longitudinal momentum to the tunnel air column. Sizing is governed by installed thrust (Newtons) and jet induction velocity rather than static duct pressure.
FHF is normally open, closing automatically at 70 °C; PFHF is a smoke fire damper with 280 °C closure; PYF is normally closed, opening on fire command for smoke extraction.
The YFVAV-S-T100 maintains zone airflow setpoints dynamically, compensating for duct static pressure fluctuations caused by other modulating zone terminals.
No. YF-MOA is a multi-outlet distribution plenum configured to order. It splits supply air from one VAV terminal into multiple configured flexible ducts matching ceiling diffusers.
Provide the four terminal temperatures (hot in/out, cold in/out), thermal duty (kW/MW), fluid flow rates, allowable pressure drop per side, working pressure, and fluid chemistry.
Choose a gasketed plate heat exchanger for the bare thermal core; choose a packaged unit for an integrated skid complete with circulation pumps, valves, expansion, and PLC controls.
Use U-tube where full bundle withdrawal for mechanical descaling is needed; use floating-coil where dynamic thermal expansion manages scale and heat-pump sources are integrated.
JFDY/JFWP provides pressure stabilization and make-up for closed HVAC loops; JFHB/JFWZ provides constant-pressure domestic/potable water supply boosting.
No. Size by design flow rate and required valve authority (ΔP). Oversized valves cause unstable hunting; undersized valves consume excessive pump head.
The DA K-01 controls the water valve while fan runs independently; the DB K Series coordinates valve modulation with a 3-speed fan.
EDV (DN20/DN25) combines motorized temperature control with automatic dynamic balancing, maintaining constant terminal flow regardless of network pressure shifts.
A balancing valve sets branch flow distribution; the 100X–900X series performs pilot-operated system functions: pressure reduction (200X), relief (500X), or DP bypass (800X).
Yes. YONGFAN provides pre-sales dimensioned product drawings, fan performance curves, and nozzle schedules to assist with consultant coordination.
Files are verified per model. Where editable 3D/BIM geometry is unavailable, use the latest approved project dimensioned drawing for spatial coordination.
Standard air filters typically dispatch in 7–15 days. Engineered fans, custom VAV plenums, and packaged hydronic skids are quoted per project schedule.
Yes. Custom dimensions, stainless-steel alloys, non-standard motor voltages, OEM private labelling, and custom plenum spigots are supported upon technical confirmation.
Base maintenance on monitored operating condition: differential pressure for filters, gas breakthrough for carbon, vibration/current for fans, and approach ΔT for heat exchangers.
Equipment can fit physically yet be impossible to service. Coordinate filter withdrawal, U-tube bundle removal, plate frame opening, and actuator access before freezing walls.
No. Replacement requires both physical fit and performance compatibility (airflow/pressure curve, filtration class, Kv/Cv, and thermal MW).
Airflow + Pressure + Temp + Voltage + Mounting + Fire/Ex Duty
Provide static or total pressure basis, motor supply (380V/50Hz), and emergency smoke temperature (280°C/30min) if applicable.
Contaminant + Grade + Airflow + W×H×D + Clean ΔP + Seal
State target standard (ISO 16890 / EN 1822), maximum available frame depth, gasket or gel seal, and downstream stage.
Gas Species + Concentration + Flow + Fresh/Recirc Mode
Identify target gases (H2S, SO2, VOCs), ambient RH/temperature, and room corrosion protection target (ISA G1).
4 Temperatures + Heat Load + Flows + Max ΔP + Pressure
Provide primary/secondary in/out temperatures, allowable pressure loss, design pressure, fluid type, and storage volume if required.
Flow + Head/Pressure + Incoming Municipal Bar + Voltage
State system water capacity, available suction pressure (for non-negative pressure JFWZ), and pump staging preference.
Function + DN + Flow + ΔP + Voltage + Signal + Fail State
Specify design flow rate, control signal (0–10V / On-Off), 24V/220V power, and spring-return fail-safe state.
Have a project requirement not covered in this FAQ? Send your equipment schedule or technical parameters — our application engineers will confirm the appropriate product configuration.
