Define one duty point for both offers
Write the required airflow per filter, its units and the selected filter dimensions before comparing prices. Keep the total system airflow separate from the flow assigned to each filter. Ask the supplier to state the initial pressure drop at that same flow, not just provide a resistance number without test conditions.
Manufacturer product tables list filter class, width, height, depth, airflow and initial pressure drop as separate fields. [1] Use that structure as a comparison checklist; the published model values are not specifications for a ZY product.
Do not compare two isolated pressure numbers
Consider a hypothetical offer A with an initial pressure drop but no airflow, and offer B with both values. Even if A lists the lower pressure, the two offers cannot yet be ranked on resistance. Ask A for the missing airflow and ask both suppliers for data at the project duty point.
Record whether the value describes a clean filter alone or a larger assembly. Keep initial resistance separate from the proposed final resistance or replacement criterion. Manufacturer datasheets state initial and recommended final pressure drop separately. [2] A replacement limit for one model is not a universal cleanroom rule.
Check the physical interface before calling it a replacement
Compare the actual width, height and depth on the dimensioned drawing, with the agreed tolerances. Confirm the frame, gasket or gel-seal arrangement, seal location, airflow direction and access for removal. A matching efficiency label or nominal front size does not confirm that the filter fits the existing housing.
Have the responsible designer or maintenance team review the offered drawing and air-system compatibility. Ask them to confirm the available pressure allowance and any housing or fan changes; do not approve substitution solely from the quotation headline.
Make the evidence and exceptions visible
Specify the classification standard and edition, required class, model identification and agreed factory test documents. Identify which installation checks and acceptance responsibilities are included in the purchase, and which belong to the project team. A filter report is not a room classification result.
Use one comparison sheet for each proposed model. Mark an unknown field “To confirm”, attach the drawing revision and ask the supplier to list deviations. Review an offer only after its operating conditions, interface and document scope are clear. This guide does not confirm stock, delivery or a tested ZY configuration.
Sources and scope
These manufacturer references show how filter data are reported. They are not ZY test reports or permission to supply a branded model. Project requirements and offered specifications must be agreed separately.
Continue your quotation preparation
HEPA quotation comparison sheet
Record the same requirements for each offer. Mark missing details To confirm and email drawings and the sheet to [email protected].
Download editable comparison sheet