A Blowtherm booth is a serious piece of finishing equipment, and it deserves the right filters — not whatever pad happened to fit last time. Blowtherm has sold booths under lines like Extra, Ultra 2000, and the World Series, and the filter sticker on your cabin may be faded, discontinued, or gone. This guide gets you to the correct ceiling and exhaust filters by model, media type, and size — without betting on a part number that may no longer exist.
You will not find fabricated “OEM equivalent” numbers here. Blowtherm revises part numbers over time, and a wrong number gets you a wrong filter. The two things that never change are the media grade and the frame opening. Match those and any equivalent filter fits.
Why Blowtherm filters differ by model
Blowtherm builds everything from compact prep stations to large downdraft production booths and industrial systems. Each pushes a specific air volume through a specific filter footprint, so an Extra, an Ultra 2000, and a World Series booth can each take different ceiling media and different exhaust configurations. That is why the reliable question is not “what is the Blowtherm part number” — it is “what media and size does my booth actually use.”
Step 1: Identify your Blowtherm model and airflow
Check the data plate on the control panel or a cabin upright for the model line and serial number. If it is missing, read the airflow:
- Full downdraft: a full filtered ceiling with exhaust pulled down through floor grating to a pit or plenum.
- Semi-downdraft: ceiling intake toward the front, exhaust to the rear.
- Crossflow / prep: front intake with an exhaust filter wall at the back.
The layout tells you which filters to buy. Our guide to downdraft, crossflow, and semi-downdraft booth filters breaks down each pattern if you are unsure.
Step 2: Ceiling (intake) blankets
Blowtherm ceiling filters are the final barrier for your make-up air, so they set finish quality. They are a tackified synthetic diffusion blanket — progressively-dense polyester media typically rated F5/M5 under EN 779 / ISO 16890 — sitting in the ceiling grid.
Identify the ceiling media
- Face direction: the denser, tackified side faces down into the cabin. Installed backward it stops diffusing — see what a wrong-side-out install does.
- Loft: ceiling blankets are thick and lofted (roughly 20–22 mm), much heavier than exhaust media.
- Format: pre-cut pads matched to the ceiling bays, or a roll you cut to length.
Measure the frame, not the old pad
Used media shrinks, so measure the opening: width x length for panels, bay width for rolls. Our measuring guide shows exactly where. For a nonstandard Blowtherm bay, order a custom-cut ceiling blanket. Shop ceiling blanket filters and ceiling intake filters.
Step 3: Exhaust filters — 6-pocket bags & space-saver bags
Blowtherm is well known for pocket/bag exhaust filters, and the exhaust side is where compliance lives. Common configurations include:
- 6-pocket bag filters — deep, extended-surface synthetic bags that maximize dust-holding capacity and service life on the exhaust plenum.
- Space-saver bag filters — shallower-depth bags for booths with a tight exhaust chamber, trading some capacity for a smaller footprint.
- Fiberglass paint-arrestor pads/rolls — used on some layouts as a first-stage arrestor.
Identify yours by counting the pockets and measuring the frame depth. Shop pocket/bag filters, exhaust filter bags, and if you have a first-stage arrestor, fiberglass pads. Browse the full range under paint booth exhaust filters.
The 98% exhaust rule (NESHAP 6H)
Your exhaust filter is a regulated control device. Under the federal area-source rule (NESHAP Subpart 6H, 40 CFR 63.11173(e)(2)(i)), the exhaust filter technology must be demonstrated to capture at least 98% of paint overspray by weight, verified by a recognized method such as ANSI/ASHRAE 52.2-2017 or EPA Method 319 (a 100-gram dust challenge). That standard is arrestance — capture by weight, not a “98% at 3 microns” particle rating, which is vendor shorthand and not the rule.
So do not improvise on the exhaust side. Buy bags or pads rated to the 98% standard and keep the efficiency documentation on file. Our NESHAP 6H & NFPA 33 compliance guide and the compliance hub with its certificate library cover exactly what to keep. This is general information, not legal advice — confirm with your state or local air authority.
Blowtherm filter cross-reference at a glance
| Position | Typical Blowtherm media | What to match | Where to buy |
|---|---|---|---|
| Ceiling / intake | Tackified polyester blanket, F5/M5 | Media grade + bay/panel size | Ceiling blankets |
| Exhaust (6-pocket) | Deep multi-pocket synthetic bag | Pocket count + frame + depth (98% rated) | Pocket/bag filters |
| Exhaust (space-saver) | Shallow-depth pocket bag | Frame size + reduced depth (98% rated) | Exhaust filter bags |
| Odd / discontinued size | Any of the above | Exact opening dimensions | Custom-cut |
How to order the exact Blowtherm replacement
- Confirm the position — ceiling, exhaust, or both.
- Confirm the media — tackified blanket, 6-pocket bag, space-saver bag, or fiberglass arrestor.
- Measure the opening — width x length, plus pocket count and bag depth for exhaust.
- Match the grade — F5/M5 ceilings; 98%-rated exhaust.
- Order stock or custom.
Not sure which fits? Start with Find My Filter, jump to the Blowtherm filter collection, or compare makes in the exact-fit filter guide for Garmat, GFS, Accudraft and more. Different booth? See our cross-references for Garmat, GFS, Accudraft, USI Italia, and Nova Verta. When the label is gone entirely, our walkthrough on finding your paint booth filter part number and the master filter size chart by brand help you decode any booth.
Frequently asked questions
Do I have to buy genuine Blowtherm filters?
No. Compliance depends on using exhaust media demonstrated to meet the 98%-by-weight capture standard and keeping the documentation — not on the brand on the frame. An equivalent-grade filter cut to your booth’s size satisfies the rule. Check your equipment warranty terms separately.
What is the difference between 6-pocket and space-saver bags?
Both are multi-pocket exhaust bags. A 6-pocket bag is deeper, giving more surface area, higher dust-holding capacity, and longer service life. A space-saver bag is shallower for booths with a tight exhaust chamber, trading some capacity for a smaller footprint. Match whichever your booth was built for by measuring the available depth.
My Blowtherm part number is discontinued. How do I reorder?
Ignore the number. Measure the opening, identify the media, and order the equivalent grade. A custom cut covers any nonstandard ceiling size.
When should I change them?
Go by static pressure on your manometer, not a set schedule — change at the booth manufacturer’s pressure limit. See when to replace paint booth filters.
Get the right Blowtherm filter, the first time
Tell us your Blowtherm model, the filter position, and the opening size (with pocket count for bags), and we’ll match the exact media — stock or custom-cut. Browse the Blowtherm filter collection or use Find My Filter, and our team will confirm the fit before you buy — every match is backed by our Fitment & Compliance Guarantee.