Vacuum FAQ

Vacuum FAQ: straight answers to the questions we hear most

These are the questions readers ask us most often — about buying, testing, and getting more out of vacuums they already own. No filler. If you have a question that isn't here, send it our way and we may add it.

Is a cordless vacuum as good as an upright?

For most people in most homes: yes, with caveats. Modern flagship cordless models (Dyson V15, Shark HyperAir, Miele Duoflex) deliver suction performance that equals or beats midrange uprights on both carpet and hard floors. The tradeoff is run time — most cordless vacuums give you 30–60 minutes on a charge, which is plenty for an average-size home but tight if you're cleaning a 3,000 sq ft house in one go. The other caveat is price: good cordless vacuums aren't cheap. If your budget is under $150, a corded upright will outperform what's available in cordless at that price. Over $250, cordless is genuinely competitive.

Does "HEPA" on the box actually mean anything?

Sort of. In the US, "HEPA" is not a regulated term for vacuum cleaners the way it is for air purifiers. A manufacturer can put "HEPA" on the box as long as the filter media itself meets the H13 filtration standard — but the filtration system as a whole (including the seal between filter and housing) can still leak particles back into your air. We test filtration as a system, not just the filter media, which is why our ratings sometimes differ from what the box implies. If you have allergies or asthma, look for vacuums we've specifically noted as "sealed system" in reviews — those are the ones that actually keep particles inside.

Can a robot vacuum replace my regular vacuum?

For maintenance, yes. For deep cleaning, no. A robot vacuum running every day or two keeps surface debris under control remarkably well, especially on hard floors. On medium-to-high pile carpet, robots struggle to agitate debris that's settled deeper into the fibers. Our practical recommendation: if you have mostly hard floors, a good robot vacuum (Roborock S8, iRobot j7+) can handle 90% of your cleaning with a full vacuum reserved for quarterly deep-cleans. If you have significant carpet, plan to supplement the robot with a stick or upright vacuum weekly.

What type of vacuum is best for pet hair?

It depends on where the pet hair is. For carpet, you want strong motorized brush roll agitation — most cordless models and uprights handle this well. The key is the brush roll design: tangle-free or self-cleaning brush rolls (Shark's Anti-Wrap, Dyson's de-tangling comb) are worth paying for if your pet sheds long hair. For hard floors, pet hair is actually easier — almost any vacuum handles it, but bare-floor suction mode (which reduces brush roll speed to avoid scattering hair) makes a noticeable difference. For upholstery and pet beds, a motorized mini-turbo tool attachment is the single most useful accessory.

How often should I replace my vacuum filter?

The honest answer: more often than you probably are. Most manufacturers recommend every 6–12 months for washable filters, but "washable" doesn't mean indefinitely reusable — HEPA media degrades with each wash, and most washable filters lose meaningful filtration efficiency after 10–15 washes. For non-washable filters, once a year is a reasonable baseline if you vacuum weekly. Signs it's time to replace regardless of schedule: the vacuum smells musty even after cleaning the dustbin, suction has declined noticeably and cleaning the dustbin and brush roll didn't fix it, or the filter material is discolored past gray into dark brown.

What do suction power numbers (watts, Pa, AW) actually mean?

"Watts" on vacuum marketing usually refers to motor input power — the electricity going in, not the cleaning performance coming out. "Pa" (Pascals) measures sealed suction, which is useful for understanding how strong suction is against a blocked nozzle — relevant for crevice tools, irrelevant for normal floor cleaning. "Airwatts" (AW) is the most useful single number because it measures airflow at a specific suction level, which actually correlates with picking up debris. Even so, none of these numbers account for brush roll effectiveness, head design, or sealing quality — which is why we test in real conditions instead of citing spec sheets.

Bagged or bagless — which is better?

For people with allergies: bagged, without question. The bag acts as a secondary filter, and disposal is completely contained — you're not shaking fine dust particles into the air when you empty it. For everyone else: bagless is more convenient and cheaper to operate (no bags to buy), but you need to be willing to clean the filter and dustbin regularly. The hygiene gap matters most in homes with allergy or asthma sufferers. If that's you, look at Miele's bagged canister lineup — it's the category leader for sealed-system filtration.

How long does a cordless vacuum battery last before it needs replacing?

Most lithium-ion battery packs in premium cordless vacuums (Dyson, Shark, Miele) will hold adequate charge for 2–4 years of regular use (vacuuming 2–3 times per week). After that, you'll notice significantly reduced run times. Replacement batteries are available for most flagship models and typically cost $40–$80 — substantially cheaper than buying a new vacuum. One practical tip: store cordless vacuums with the battery partially charged (40–60%) if you're not going to use them for a month or more. Full charge storage accelerates battery degradation.

What do suction power numbers actually tell me?

"Watts" refers to motor input power — electricity in, not cleaning performance out. "Pa" (Pascals) measures sealed suction, relevant for crevice tools but not normal floor cleaning. "Airwatts" (AW) is the most useful single number — it measures airflow at a specific suction level, which actually correlates with picking up debris. Even so, none of these numbers account for brush roll effectiveness or head design, which is why we run real-world tests instead of citing spec sheets.

Are cheap robot vacuums ($150 and under) worth it?

For hard floors in smaller spaces: sometimes. For carpet: almost never. Budget robot vacuums typically lack the suction power and brush roll design to do meaningful work on carpet beyond surface debris. They also tend to have shorter-lived batteries, less reliable navigation (random-pattern vs. systematic mapping), and no obstacle detection worth mentioning. The useful price floor for robot vacuums is around $250–$300, where you start getting systematic LiDAR mapping and enough suction to handle low-pile carpet. The one exception: if you have a very small space (studio apartment, under 500 sq ft) that's entirely hard floors, a $150 budget robot running daily can genuinely keep it clean.

How do I know which Vacuwiz review to trust for my situation?

The most important thing is to read the review summary for the specific use case, not just the star rating. A vacuum can earn 4 stars for a small apartment with hard floors and be a poor choice for a house with shag carpet and three dogs. We write review summaries with a specific "best for" statement — if your home matches that description, the rating is meaningful for you. If it doesn't, read the full review and look at the subsection scores, which break out carpet performance, pet hair, hard floors, and maintenance separately. Still unsure? Ask us directly — we try to answer specific buying questions when we can.

More questions? Browse our full review library, or contact us directly.