Filter Finder
Find your filter by size, not by name
Got the old filter in your hand but not its part number? Tell us its shape and size — we'll match the exact Jasun product, the closest standard sizes that fit, or build it custom. Enter any one detail to start.
What shape is it?
Recognise the form, not the name. Optional — skip straight to size or class if you prefer.
Size & class
Nothing standard fits?
Never a dead end. If no stock size is close enough, we build to your exact spec — any size, any grade, dispatched from Bridgwater. We'll carry over whatever you've entered.
Finding a filter by its size
Most replacements start with the old filter in hand and no part number on it. Because air filters are made to a small set of standard sizes and classes, you can find the right one from its dimensions alone — whatever the trade calls it (a panel filter is also a flat, slab, card-frame, AHU or furnace filter). Measure the face as height × width, then the depth, and enter the millimetres above. The Finder matches the exact Jasun product or the closest standard size that fits your housing.
Don't know your class? The grade (G4 to F9, or the ISO 16890 ePM ratings) is often printed on the old frame — but you don't need it. Enter the size alone and we'll narrow the available classes for you, or call 01278 452 277 and we'll identify it.
Common questions
What if my exact size isn't a standard?
Filters seat with a few millimetres of clearance, so a near-standard size usually fits. Enter your measured size and we'll point you to the nearest stock options in the product list. If nothing is close enough, we build the filter to your exact spec.
How do I measure my filter?
Measure the face (the side air passes through) as height × width, then the depth — the thickness of the frame in the direction air flows. Use the actual measured millimetres, not the "nominal" size printed on some frames.
What's the difference between F7 and ePM1?
They describe the same kind of fine filter under two standards. F7 is the older EN 779 grade; ePM1 is the current ISO 16890 family it maps to. A filter marked F7 and one marked "ePM1 50–65%" are broadly equivalent.
Do I need to know the brand of my old filter?
No. Air filters are interchangeable by size and class regardless of who made the original. Match the dimensions and grade and you'll get a filter that fits the same housing.
Can you make a non-standard size?
Yes — custom is around half of what we make. If no standard size fits, request a custom size and we build to your exact spec, any grade, dispatched from Bridgwater.
How fast can I get a replacement?
Standard sizes typically ship in 3–10 working days from our UK factory. Stocked lines dispatch sooner; custom builds depend on spec — we confirm a lead time on your request.