It is extremely important on all replacement filters, Especially on units used for smoke.
1: It seals the unit so there are no air leaks, when an old gasket is used (The weight of the carbon filter flattens the gasket), creates an air leak, when there is an air leak, the filters don’t work to full capacity.
2: The Felt Gasket may retain odors over time, when an old gasket is used with new filters, this is where sometimes… a client may feel there is a smell coming from the new filters.
3. Gaskets are imperative to ensure proper seal for optimal filtration.