Freo Z Ultra vs BU3521UK Cordless Vacuums

Torn between Freo Z Ultra and BU3521UK for your next cordless vacuum?

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

By assessing these vacuums – the Freo Z Ultra and BU3521UK from NARWAL and SHARK, you get the best floorcare machine.

Best Cordless Vacuum Pick

NARWAL Freo Z Ultra vs SHARK BU3521UK – key Specifications

Freo Z Ultra and BU3521UK Cordless Battery Run Time

NARWAL Robot cordless vacuums, like the Freo Z Ultra, 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 Narwal Freo Z Ultra which has 210 minutes life.

• NARWAL Freo Z Ultra Runtime: 210 mins continuous vacuuming
• SHARK BU3521UK Runtime: 40 mins continuous vacuuming

Charging times between the Freo Z Ultra and BU3521UK varies – check manual.

Cordless Vacuum Dust Tank Capacity

Both Narwal Freo Z Ultra and Shark BU3521UK are bagless, storing dust, hairs, dirt, and debris inside a sealed 2.5 litre and 0.42 litre tank, respectively. The BU3521UK by SHARK holds up to 0.42 Litre of compressed dirty particles. The Freo Z Ultra by NARWAL has a capable capacity of 2.5 litre for manual disposable.

• Freo Z Ultra onboard dirt/dust tank size: 2.5L
• BU3521UK onboard dirt/dust tank size: 0.42L

Floor Cleaning Types

Narwal’s Freo Z Ultra 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 Freo Z Ultra can’t vacuum liquids. For this, a SHARK or NARWAL ‘wet and dry’ vacuum is needed.

Most Narwal and Shark battery powered vacuums include accessories. Check Freo Z Ultra or BU3521UK manual for specifications and attachments.

Vacuum Filtration

The BU3521UK and NARWAL Freo Z Ultra include effective filters to capture dust, dander, pollen, hairs, and fibres.

NARWAL and SHARK use HEPA, foam, or cloth, filters. Freo Z Ultra and BU3521UK maintain suction and clean exhaust air.

SHARK and NARWAL Reviews

Combined feedback from 406 reviewers shows the Freo Z Ultra with a rating of 4.4/5 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
NARWAL	Freo Z Ultra	210 M	4.5	2.5L	£949.00
SHARK	BU3521UK	40 M	2.7	0.42L	£349.99