A German buyer asking whether your bag filter replaces an installed unit needs more than a class label and a price. Match dimensions, airflow, resistance, sealing and replacement conditions before comparing offers. We can coordinate agreed German sample reception and commercial discussions; the manufacturer and customer retain responsibility for selection, testing and system approval.
A lower purchase price may leave the buyer with an unresolved installation or operating-cost question. Find out which requirement prevents approval before offering another discount. An engineering contact needs a comparable specification, while purchasing needs a clearly defined supply item.
Build a usable replacement specification
This discussion concerns general-ventilation bag filters. Do not extend the approach into a promise about cleanroom HEPA, process dust collection, high-temperature or explosive-atmosphere applications. Obtain the actual installation and operating requirements first.
The MANN+HUMMEL classification guide distinguishes ISO 16890 groups. Request the full class designation and product-specific evidence. Do not create a universal one-to-one conversion from an old EN779 class or treat a general standards brochure as a report for the offered unit.
| Customer input | Manufacturer response | Decision enabled |
|---|---|---|
| Frame dimensions, header and seal | Dimensional drawing and interface limits | Whether to send a candidate sample |
| Operating airflow and environment | Resistance at a matching operating point | A comparable technical offer |
| Full efficiency requirement | Model-linked classification evidence | Customer review of the documented scope |
| Replacement practice | Pressure or time-based constraints | An agreed evaluation record |
Compare like operating points
Camfil’s Standard-Flo sheet dated 28 March 2025 provides a useful published example. Three configurations share a 592x592mm face and 3400m³/h nominal airflow but have different initial resistance. The comparison illustrates a purchasing question; it is not a brand ranking or a claim that we sell or represent Camfil.
Published initial-resistance comparison
| Configuration | Nominal airflow | Initial resistance |
|---|---|---|
| 600mm depth,8 bags | 3400m³/h | 85Pa |
| 600mm depth,6 bags | 3400m³/h | 95Pa |
| 370mm depth,6 bags | 3400m³/h | 135Pa |
Calculate a conditional energy example
Eurovent4/24 (2023) addresses actual airflow, dimensions, replacement approach, hours and fan efficiency. That is why a quoted initial resistance alone cannot establish the customer’s annual energy cost.
The following figures are invented calculation inputs, not tests or predictions for the products above. Assume constant3400m³/h, average resistance100Pa versus140Pa, total fan efficiency0.60,4000 operating hours and electricity at €0.20/kWh. For the filter-resistance component only, Q=3400/3600=0.944m³/s and input power P=Q×Δp/η.
| Assumed calculation | A | B |
|---|---|---|
| Average resistance | 100Pa | 140Pa |
| Input power | 157.4W | 220.4W |
| Annual energy | 629.6kWh | 881.5kWh |
| Annual energy cost | €125.9 | €176.3 |
The illustrated difference is approximately€50.4/year. A€20 purchase-price premium would be worth investigating only if the inputs apply. Purchase, labour, downtime and disposal are excluded; airflow and efficiency are held constant. Dust loading and real operation alter the result. Replace assumptions with defensible operating records before making a commercial claim.
Define the sample evaluation
Before dispatch, name the people checking fit, installing the sample and recording airflow and resistance. Give the sample a model, configuration and batch identity. Agree the observations that will support the buyer’s decision rather than allowing a salesperson to invent an operating limit.
Photographs and readings need context: date, location, method and instrument information where relevant. Missing context is a request for information, not evidence of approval. If independent testing is required, agree the provider, method, scope and fees first. Local reception does not imply a certified test facility.
Convert the approved sample into a supply item
Lock the approved frame, medium, bag arrangement, seal and packaging into the quotation. Define how changes will be communicated and reviewed. Approval of one configuration cannot silently cover every item in the range.
Separate evaluation charges, incoming inspection, returns and supply responsibilities. A German reception address does not establish distribution rights. Company and VAT arrangements should reflect the actual sale, and customer test materials should remain confidential unless their use is authorised.
Arrange local commercial support
Send your data sheet, installed-unit information, application, airflow, quantity and unresolved buyer question. We can discuss German sample reception, product meetings and authorised commercial follow-up, as well as company and VAT arrangements for local trading.
Confirm storage, staff, authority, fees and confidentiality before shipping. Technical parties retain approval decisions. Discuss German industrial-filter sales support →
Sources and checks
Checked: 2026-10-28