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عربىTechnical Parameters for Airtight Construction
Airtightness is described by the air leakage rate at a stated pressure, for example liters per second per square meter of envelope at 50 or 250 Pa. There is no single value for all cleanrooms. Your design team sets the target according to class, pressure differential, containment needs and energy goals.
| Leak path | Typical cause | Our approach |
|---|---|---|
| Panel joints | Gaps between panels or poor edge sealing | Precisely cut panels, tongue-and-groove or profile joints, sealant |
| Wall-to-ceiling and wall-to-floor junctions | Movement, uneven surfaces | Coved profiles, sealed channels, level base |
| Door frames and leaves | Weak gaskets, poor closing | Gasketed frames, bottom seals, adjustable hinges |
| Window frames | Gaps around glass or frame | Flush windows, silicone seals |
| Penetrations (cables, pipes, ducts) | Holes cut and left unsealed | Pre-planned openings, sleeves, sealant or fire-stop material |
| Lights, grilles, switches | Open cut-outs in ceilings and walls | Sealed fittings, gasketed frames |
| Ceiling plenum | Joints in grid or panels | Sealed grid, gasketed ceiling panels |
Why it matters:
- Pressure control: a tight room holds 10–15 Pa between classes with less supply air.
- Energy: leakage forces fans and cooling coils to work harder.
- Humidity: dry rooms and humidity-sensitive processes depend on a tight envelope.
- Contamination: uncontrolled air can bring particles and microorganisms from outside.
We customize panel, door and window details for each project and class.
Please also tell us the room pressure, supply air quantity and any test pressure you plan to use, so we can match gaskets, door closing force and sealing details to the real conditions of your project.
Cross-Border Delivery and Localized Construction Support
Airtightness is won or lost on site, where thousands of joints, corners and penetrations are sealed by hand. For overseas projects, we therefore support the installer with clear sealing methods, labeled drawings and, where needed, supervision.
- Target setting: we agree the leakage target, test method and test pressure with your design team.
- Drawings: joint details, junctions and penetration plans are agreed before production.
- Production: panels, doors and profiles are produced to tight tolerances and numbered.
- Packing and shipping: flat-pack loading with edge protection, and documents with FOB, CFR or CIF terms.
- Installation support: manuals, video guidance or a supervising engineer.
Local construction: the best results come from a clear sequence: build the walls, install door frames and windows, complete ceilings, then seal all joints and penetrations in one controlled stage. Services should be installed before final sealing, and any later hole must be sealed with an approved method. Using the right sealant, correct tooling and clean joints matters as much as the product.
After sealing, the contractor or an independent tester should carry out a leak test, such as a pressure decay test or a measurement of supply air needed to hold pressure, and then repair leaks with smoke or ultrasonic detection. Local rules apply, and your engineer remains responsible for approvals.
Staged shipments can also be arranged when the building is handed over in phases. For large projects, we suggest approving one finished sample room, sealed and tested, before the remaining rooms are built, so the team can agree on the method and the acceptance standard.
Quality Control and Certification
Airtightness is proven by testing the finished room. A panel or door is not "airtight certified" on its own, and we do not claim this. We control the things that we can: dimensions, edges, gaskets and packing, so the installer starts with parts that fit well.
| Control step | Inspection | Why it matters |
|---|---|---|
| Incoming materials | Sheet, core, profiles, gaskets, sealant | Known quality |
| Panel production | Dimensions, squareness, flatness, edge sealing | Tight joints |
| Profile check | Cut length, straightness, cove radius | Neat, sealed junctions |
| Door inspection | Frame squareness, gasket compression, closing force | Low leakage at doors |
| Window inspection | Frame flushness, glass seal | No gaps |
| Packing | Count, labels, edge protection | Undamaged edges |
Documents available: material specifications, factory inspection records and, where available, test data for doors or panel systems. We can also share typical sealing details and installation procedures.
Please tell us if your project requires a specific leakage test, for example a pressure decay test at a stated pressure, so we can plan details and give installation guidance. Customer audits of our factory and sample approvals are welcome.
HVAC engineers and validation teams often ask for evidence before they accept an envelope design. We provide material data, typical sealing details and answers to technical questions, and we welcome factory visits or live video tours. Batch records are kept for each project, so questions about a specific room can be traced to production.
We recommend agreeing the leakage test method and pass criteria before construction, because a clear target helps everyone work toward the same result.
After-Sales Service and Response Capability
Airtightness can change over time. Gaskets wear, sealants age and new penetrations appear when equipment is added. Our after-sales service helps you find leaks, repair them with matching materials and keep the room within its target.
- Fast communication: technical questions answered in English by email, phone or messaging.
- Remote diagnosis: pressure trends, photos and videos help us suggest likely leak locations.
- Spare parts: gaskets, bottom seals, hinges, closers, windows and sealants.
- Modification advice: how to add openings without losing tightness.
- Engineer visits: by arrangement, including leak detection support.
Typical symptoms and responses:
| Symptom | Possible cause | Suggested action |
|---|---|---|
| Pressure differential falls | Gasket wear, new opening, loaded filter | Replace gasket, reseal, check filter |
| Supply air needed to hold pressure rises | New leaks in ceiling or walls | Smoke or ultrasonic leak search, reseal |
| Humidity drifts | Door left open, leak at junction | Check door timing and sealed joints |
| Whistling at door | Worn bottom seal | Replace seal, adjust door |
We suggest recording room pressure and supply air regularly. A slow change in the numbers is often the first sign of leakage.
Leak hunting is easier with good records. Please keep the commissioning pressure and supply air values, and compare them with current readings. If the room needs more air than before to hold pressure, a leak has probably appeared. Send us the numbers, photos and recent changes in the room, and our engineers will suggest likely locations based on the project drawings.
Replacement gaskets and seals are made to the original specification, so closing force and sealing match the existing doors. For urgent cases, we discuss the fastest shipping option.
A small stock of bottom seals, gaskets and sealant helps you act the same day.
Commercial Terms, Warranty and Lifecycle Cost
A tighter envelope costs more at the start, because it needs better tolerances, better gaskets and more careful sealing. The return comes from lower fan and cooling energy, steadier pressure and fewer failed tests, and in many projects it pays back within a short time.
| Item | Our approach |
|---|---|
| Quotation | Itemized by area and component, with drawings and sealing details |
| Trade terms | FOB, CFR or CIF, defined in the quotation |
| Payment | Commonly a deposit with balance before shipment or against documents; final terms in the contract |
| Warranty | Defined by component group in the contract |
| Lead time | Given after drawing confirmation |
| Customization | Panel, profile, door and window details |
Where the savings come from:
- Fan energy: less leakage means less supply air is needed to keep pressure.
- Cooling and dehumidification: less uncontrolled outside air enters the room.
- Testing: a tight room passes pressure and recovery tests more easily.
- Maintenance: fewer pressure alarms and less rework.
Leak testing, HVAC balancing, sealant labor beyond our scope and permits are outside our supply unless agreed. Warranty exclusions are stated clearly in the contract.
When comparing quotations, ask each supplier to state tolerances, gasket types, door bottom seals, window details and sealing methods, not only panel thickness and price. Differences in these details explain much of the long-term energy cost.
We provide itemized quotations and can show alternatives, such as higher-grade doors for pressure boundaries and standard doors elsewhere.
We are glad to explain every line of our quotation and to prepare alternative options if you need to adjust the budget.
Real Factory Strength for Airtight Projects
Tight joints begin with precise parts, so manufacturing consistency matters. Pharma United Co., Ltd., founded in 2006, runs two factories in Kunshan and Qianjiang covering 20,000 m², with more than 60 staff. We are a manufacturer, not a trading company.
| Indicator | Information |
|---|---|
| Experience | 20+ years in cleanroom engineering |
| HPL cleanroom panels | About 250,000 m² per year; China's largest HPL cleanroom panel manufacturer |
| Container shipments | More than 1,000 forty-foot high-cube containers per year |
| Location | Kunshan, about 30 km from Shanghai |
| Product range | Panels, doors and windows, equipment, modular PODs, HEPA products |
| Service | Design, manufacture and installation support |
Why this helps airtight projects: large panel output with controlled production means consistent dimensions, so joints fit as designed. Because panels, doors, windows, Air Showers and Pass Boxes come from one source, interfaces match and fewer gaps appear.
Samples, references, factory visits and video tours are available on request. Our engineers answer technical questions directly.
Our designers prepare layouts and detail drawings, our engineers review sealing and interface details, and our production teams run dedicated lines for panels, profiles, doors and equipment. Export coordinators prepare packing and documents for shipments to many countries.
Customers in pharmaceutical, hospital and electronics fields return for new rooms and spare parts, and we can share photos and videos of completed rooms on request. Visitors are welcome at our factory by arrangement.
We reply promptly and in plain language.
Our staff reply promptly and in plain language, and our designers can adapt standard layouts to your building and your process.
Airtight Cleanroom Construction FAQ
Q1. How airtight should a cleanroom be?
It depends on class, pressure cascade, humidity and energy goals. Your designer sets a target leakage rate at a stated pressure.
Q2. How is airtightness tested?
Common methods include a pressure decay test, measuring the supply air needed to hold a set pressure, and leak detection with smoke or ultrasonic tools.
Q3. Where do most leaks occur?
Typically at penetrations, wall-to-ceiling junctions, door frames, light fittings and ceiling grids, more than at the panel faces themselves.
Q4. Do airtight rooms need special doors?
They need gasketed frames, good closing force and bottom seals. Interlocks keep doors from opening together.
Q5. Can I make an existing room tighter?
Often yes, by resealing joints, replacing gaskets and sealing penetrations, though results depend on the existing construction.
Q6. Does airtightness affect energy cost?
Yes, leakage raises fan, cooling and dehumidification energy, and a tight envelope reduces it.
Q7. How do I get a quotation?
Send your target class, pressure differential, floor plan and destination country.
Q8. How much energy can a tighter room save?
It depends on the starting leakage, the room class and the climate. Leakage forces more supply air, cooling and dehumidification, so reductions can be significant, and your HVAC designer can estimate the saving.
Q9. Do cleanroom lights leak?
They can, if cut-outs are not sealed. Choose gasketed fittings and seal frames to the ceiling.
Q10. Can you help with layout?
Yes, we prepare layout and sealing proposals that your HVAC designer can adjust.
Q11. Do you offer samples?
Yes, samples of joints and gaskets can be sent for approval.
