RC4S vs BU3521UK Cordless Vacuums

Torn between RC4S and BU3521UK for your next cordless vacuum?

We examine the RC4S – a battery-power vacuum by Aeno, comparing runtime, dust tank, and costs, with – BU3521UK by Shark, analysing real-world vacuuming performance.

By assessing these vacuums – the RC4S and BU3521UK from AENO and SHARK, you get the best floorcare machine.

Best Cordless Vacuum Pick

AENO RC4S vs SHARK BU3521UK – key Specifications

RC4S and BU3521UK Cordless Battery Run Time

AENO Robot cordless vacuums, like the RC4S, provides lightweight portability without mains cables. BU3521UK Stick is also cordlessly powered by a SHARK rechargeable battery.

The Shark BU3521UK has a battery supply runtime of 40 minutes of cleaning, compared to the Aeno RC4S which has 250 minutes life.

• AENO RC4S Runtime: 250 mins continuous vacuuming
• SHARK BU3521UK Runtime: 40 mins continuous vacuuming

Charging times between the RC4S and BU3521UK varies – check manual.

Cordless Vacuum Dust Tank Capacity

Both Aeno RC4S and Shark BU3521UK are bagless, storing dust, hairs, dirt, and debris inside a sealed 0.3 litre and 0.42 litre tank, respectively. The BU3521UK by SHARK holds up to 0.42 Litre of compressed dirty particles. The RC4S by AENO has a capable capacity of 0.3 litre for manual disposable.

• RC4S onboard dirt/dust tank size: 0.3L
• BU3521UK onboard dirt/dust tank size: 0.42L

Floor Cleaning Types

Aeno’s RC4S and Shark’s BU3521UK brush heads are effective on every surface – carpets & deep-pile rugs, hard floors (laminate, wood, tiles), vinyl, even upholstery, and stairs.

Their only limitation is the BU3521UK and RC4S can’t vacuum liquids. For this, a SHARK or AENO ‘wet and dry’ vacuum is needed.

Most Aeno and Shark battery powered vacuums include accessories. Check RC4S or BU3521UK manual for specifications and attachments.

Vacuum Filtration

The BU3521UK and AENO RC4S include effective filters to capture dust, dander, pollen, hairs, and fibres.

AENO and SHARK use HEPA, foam, or cloth, filters. RC4S and BU3521UK maintain suction and clean exhaust air.

SHARK and AENO Reviews

Combined feedback from 56 reviewers shows the RC4S with a rating of 4.3/5 stars, and the BU3521UK vacuum gains a 4.4/5 average from 128 reviews, showing comparable reliability results.

Brand	Model	Runtime	Weight	Tank	Best Price
AENO	RC4S	250 M	2.8	0.3L	£599.00
SHARK	BU3521UK	40 M	2.7	0.42L	£349.99