FAQ – Frequently Asked Questions

Answers to the questions we receive most often from cleanroom operators and buyers.

Q1. What is the difference between HEPA and ULPA filters?

HEPA filters (H13-H14) remove at least 99.95%-99.995% of particles at MPPS. ULPA filters (U15-U17) remove up to 99.999995%, for the most demanding cleanrooms such as semiconductor fabs and biosafety facilities.

Q2. What filter class do I need for an ISO Class 5 cleanroom?

Typically H13 or H14 HEPA filters at the terminal. Your specific requirement depends on the application and local regulations — send us your spec and we will confirm.

Q3. Are your filters tested and certified?

Yes. Every filter batch is tested in our CNAS-accredited laboratory, and HEPA/ULPA filters are individually scanned and leak-tested to EN 1822 before shipment. Test reports are available on request.

Q4. Do you support custom sizes?

Yes, custom sizes are our specialty. Provide your housing dimensions and we will manufacture to fit, with short lead times.

Q5. What is the difference between gel-seal and gasket-seal filters?

Gasket-seal filters use a compression gasket (EVA/PU). Gel-seal filters use a knife-edge frame that immerses into a gel channel in the housing, providing a more reliable, leak-free seal for critical applications.

Q6. Do you offer high-temperature filters?

Yes. Our high-temperature HEPA series is rated for continuous operation at 250°C, 300°C and 350°C, designed for spray plants, coating lines and drying ovens.

Q7. How often should HEPA filters be replaced?

It depends on pressure drop, particle load and application. Most operators replace final HEPA filters when pressure drop exceeds the design limit (often 2-3 years in well-prefiltered systems). We recommend monitoring differential pressure.

Q8. What is your delivery time?

Standard products ship quickly from stock; custom-size filters typically require 2-4 weeks depending on quantity and specification.

Q9. What is the minimum order quantity?

We are flexible. Small trial orders are welcome, and volume pricing is available for project and ODM orders.

Q10. Do you ship worldwide?

Yes, we export to more than 100 countries with careful export packing and full documentation.

Q11. Can I get samples?

Yes. Sample orders are available for evaluation. Contact us with your application details.

Q12. How do I request a quote?

Use the Request a Quote page or contact our sales team with your dimensions, efficiency class and quantity.

Q13. What certifications does Onecleans hold?

Our factory operates with CNAS-accredited testing, ISO quality management, 80+ filtration patents and German R&D collaboration. Specific certificates can be shared on request.

Q14. Do you provide installation guidance?

Yes, we provide installation instructions with every order, and our engineers can advise on installation and leak-testing procedures.

Q15. Do you provide prefilters for HEPA protection?

Yes, we supply G4-F9 prefilters. Using prefilters upstream of final HEPA filters significantly extends filter life and reduces operating cost.

More questions? Ask our engineers.