9L vs 6L Henry Hoover Bags — Why Size Matters

You buy a “compatible” Henry Hoover bag from the supermarket or a third-party seller. It fits the inlet, the seal looks fine, the price is decent. You go home and start vacuuming. A few rooms in, the bag is full. You change it. Carry on. A few more rooms — full again. Strange. Genuine Henry bags don’t fill up this fast, do they?

Genuine Numatic bags are 9 litres. Most compatibles are 6.

Numatic — the British manufacturer behind Henry, Hetty, Harry and James — designs every Henry-family vacuum around a 9-litre disposable bag (technical part code NVM-1CH). That’s the original capacity the machine is engineered for.

When third-party manufacturers make “compatible” bags, they have a choice: copy the original 9L size, or make the bag smaller — usually around 6 litres — to save on material costs. Most go small. The bag still fits, the seal still works, the seller can list it at a lower price. But you now have a bag that holds 50% less dust than the original.

You probably wouldn’t notice on the box. The packaging will say “fits Henry, Hetty, Harry, James” and quote pack count and price. It will rarely tell you the litres.

What a smaller bag actually costs you

The maths is uncomfortable.

• Two-thirds the capacity means you change bags about 1.5× more often.
• A pack of 10 × 6L bags holds about the same total dust as 6.7 × 9L bags.
• So when a competitor sells 10 “compatible” bags for £8 and we sell 10 × 9L bags for £9.99 — once you adjust for capacity, our pack is around 20% cheaper per litre of dust held.

It also adds up over the year. The average UK household does about 50 vacuum sessions per year. With a 9L bag that’s roughly 6 bag changes. With a 6L bag, it’s 9. So you go through three more bags every year for no reason other than the bag is smaller.

Beyond cost: the suction problem

There’s a less obvious problem too. As a vacuum bag fills, airflow restricts. By the time a 6L bag is hitting the 80% full mark you’re already losing suction — and the vacuum has to work harder, drawing more power and shedding fine dust back into the room. A bigger bag has more headroom before this happens, which keeps the machine running at its design suction for longer between changes.

How to check what bag you’re actually buying

You shouldn’t have to be a detective. Three quick checks:

1. Look for “9L” or “9 litre” in the listing. If the seller doesn’t state capacity at all, assume it’s the smaller size — they’d shout about 9L if it was 9L.
2. Check the part code. Genuine and full-capacity compatibles will reference NVM-1CH or 604015. Smaller compatibles often invent their own.
3. When the bag arrives, hold it next to a known 9L genuine Numatic bag. A 6L compatible is visibly shorter and narrower.

Where NuClean stands

We’re a UK brand that makes one product properly: a full 9-litre compatible Henry Hoover bag with multi-layer microfibre filtration and a secure leak-proof seal. Sized like the original, priced like the compatibles. It fits every Henry-family vacuum (HVR160, HVR180, HVR200, HVR240, HVR250, HVR300, Het160, HVA160) and is the same NVM-1CH bag type as the genuine.

It’s the only compatible we know of at full 9L size. We mention this often because — until the rest of the market catches up — the size difference is the main reason to choose us.

Written by the NuClean team. We’re an independent UK brand; NuClean bags are a compatible replacement, not manufactured by Numatic. The Numatic and Henry names and part numbers are used for reference only.