Independent Hands-On Test: We Tested the Jiuberry Tranquil Dwell at 31°C in a London Attic Apartment
Attic apartment in London’s West End, around 64 m², outside temperatures up to 34°C — how the Jiuberry Tranquil Dwell performed in the bedroom and the converted attic home office.
If you’ve spent any time on Facebook, Instagram, or your usual news sites in the past few weeks, chances are you’ve come across the same ad we did: the Jiuberry Tranquil Dwell Portable Air Conditioning.
A small white cooling unit styled like a wall-mounted AC. The manufacturer claims it can drop a room from 35°C to 17°C in a short time — no drilling, no outdoor unit, no annual F-Gas servicing required. Stacks of enthusiastic comments. Ads on every corner. And at least three readers who emailed us asking if it’s for real.
So we decided to check it out ourselves. We ordered a test unit, installed it in a typical attic apartment in London’s West End, and ran it for 14 straight days in two different rooms — no deference to the marketing claims. Here’s what we found.
Our Verdict Up Front
The Jiuberry Tranquil Dwell Portable Air Conditioning delivers surprisingly close to what the advertising promises.
For everyday summer heat in a rental apartment — especially under the roof — it’s a lot more practical than a traditional AC. No drilling, no outdoor unit bolted to the facade, no £300 power bill. Plug in, it cools. The full test results, step by step:
Ordering & Delivery
First hurdle: How reliable is the manufacturer? The Jiuberry Tranquil Dwell Portable Air Conditioning is sold exclusively through the official manufacturer website — not on Amazon, not on eBay, not at B&Q. That immediately makes a lot of readers suspicious (us too). More on that later in the article.
We placed our order Monday. Payment via PayPal or credit card. Order confirmation arrived within minutes. Shipping confirmation with UPS/DHL tracking code: the next morning. Delivered several days after ordering.
Packaging: Solid. Printed cardboard box, with the unit nestled cleanly in foam. Inside the box:
- The Jiuberry Tranquil Dwell Portable Air Conditioning itself (just over two pounds, noticeably lighter than expected)
- Included wall mounting bracket with anchors and screws
- Power cord with standard 120V plug (about 6 ft)
- English-language manual (clear enough for anyone over 70 to follow)
- Quick-start sticker showing the three main touch controls
First impression: Feels like a quality product, not a cheap plastic gimmick. The housing is well built, no rattling, no visible seams. The touch display is large and easy to read — especially important for older users.
Installation: Plug It In, You’re Done
This is the biggest difference compared to a traditional AC. For a split-system AC we would have needed: a hole drilled through the exterior wall, an outdoor unit bracket on the facade, written approval from the landlord, a licensed HVAC contractor, an appointment, and around £2,400.
For the Jiuberry Tranquil Dwell Portable Air Conditioning, here’s what we needed: two drywall anchors and a free 120V outlet. Bracket on the wall, unit on the bracket, plug in. We timed it — 5 minutes 21 seconds, no contractor required.
Test 1: Bedroom Under the Roof
Room: 14 m² bedroom | Location: Top floor, west-facing | Outside: 32°C | Room temp evening: 29°C
The Starting Point
The most important room for our tester Emma (38). She regularmente sleeps badly in the summer — the bedroom sits right below the attic and heats up to over 29°C. Her workaround until now: two floor fans on max, windows open. The result: restless sleep.
How the Test Went
We mounted the Jiuberry Tranquil Dwell Portable Air Conditioning at 9:30 p.m. and set it to 22°C. After about 10 minutes the room felt noticeably cooler; after 20 minutes the thermometer read 23°C.
What surprised us most: the noise level. We measured from the bed: 36 dB. That’s noticeably quieter than a regular fan and absolutely quiet enough to sleep through.
Test 1 Result: 29°C down to 23°C in 20 minutes, 36 dB measured from the bed. Emma slept straight through from 11:15 p.m. to 6:45 a.m.
Test 2: Home Office in the Converted Attic
Room: 11 m² | Outside temp: 33°C | Room temp 3 p.m.: 33°C
The Starting Point
The honest worst-case scenario. Emma works from home three days a week directly under the roof with a sloped skylight. In summer the room is unusable. Before our test, she had spent two weeks working at her dining table.
Jiuberry Tranquil Dwell Portable Air Conditioning in Emma’s attic home office — working at 24°C while it’s 33°C outside
How the Test Went
We set the unit on a dresser, fan speed 2, and turned it on at 10:30 a.m. After 30 minutes, the room sat at 24°C and stayed there — even with the sun blasting through the skylight.
Power consumption over 8 hours: 0.38 kWh. That comes out to about 17p for a full workday. A comparable split AC would have used roughly ten times as much.
Test 2 Result: 33°C down to 24°C in 30 minutes, stable for 8 straight hours. Emma got her attic office back.
Three Bonus Use Cases We Tested
During the 14-day test we also tried the unit in a handful of other settings as they came up. Here’s the short version:
Senior Apartment
We tried the unit at Emma’s parents’ place. Operation via large touch display, no problem. Power bill, also no problem.
RV / Motorhome
Runs off any standard 120V outlet. RV test in the Scottish Highlands at 30°C: 14 m² down to 22°C in 12 minutes.
Kids’ Bedroom
Our neighbor’s five-year-old, allergies, terrible summer sleep. Three nights with the Jiuberry Tranquil Dwell Portable Air Conditioning: first full week of sleep since March.
How Does the Jiuberry Tranquil Dwell Portable Air Conditioning Actually Work?
Unlike a traditional AC with a compressor and chemical refrigerant, the Jiuberry Tranquil Dwell Portable Air Conditioning uses airflow geometry. Warm room air is progressively cooled through three sequential cooling chambers.
Jiuberry Tranquil Dwell Portable Air Conditioning airflow in cross-section — manufacturer’s functional schematic
The advantage of this design: No annual F-Gas certified refrigerant servicing required (UK requirement for split systems), no outdoor unit, much lower power draw. The trade-off: A single unit has limited cooling capacity — for rooms over 30 m² with south-facing exposure, the manufacturer recommends running two units in parallel.
"A traditional AC solves the problem with brute force — lots of compressor, power, and
chemistry. The Jiuberry Tranquil Dwell Portable Air Conditioning solves it with geometry. The end
result is the same, just without the collateral costs."
— Mike Bennett, Jiuberry
Tranquil Dwell Portable Air Conditioning inventor
Measured in the Lab
Power consumption per hour at medium setting: 0.048 kWh. At current UK electricity rates: about 2£ per hour. A comparable split AC pulls 0.5–0.7 kWh.
What Verified Buyers Are Saying
To make sure we weren’t just trusting our own impression, we went through the verified buyer reviews online in parallel. The picture is strikingly consistent: 20,000+ verified reviews, averaging 4.8 out of 5 stars. The handful of negative ones almost exclusively concern shipping delays during peak season — not the product itself.
Three reviews we found particularly telling:
★ ★ ★ ★ ★ “I had a hard-installed AC unit that cost me £1,490. My June power bill came in £160 lower than last year. I was skeptical — but this thing does what it’s supposed to.” — Verified Buyer
★ ★ ★ ★ ★ “Renter in Birmingham, landlord said no to AC for years. Ordered the Jiuberry Tranquil Dwell Portable Air Conditioning. Legally it's like hanging a picture. Best purchase in years.” — Steve H., 41
★ ★ ★ ★ ★ “I’m 71 and couldn't sleep when it got hot. First complete summer night of sleep in years. A lifesaver.” — Helen M., 71
⚠ Important: Watch Out for Fakes
Beware of knockoffs on Amazon or eBay. These do not come from the original manufacturer and lack the quality and 30-day guarantee.
Common Questions
Q: What room size is the Jiuberry Tranquil Dwell Portable Air Conditioning designed for?
Optimal for rooms up to about 25 m². For larger rooms, run two units in parallel.
Q: How loud is the unit at night?
Measured from the bed: 36 dB. Quieter than a regular fan.
Q: Do I need landlord or leaseholder approval?
No. There’s no structural modification. Legally it’s treated the same way as hanging a picture.
30-Day Money Back Guarantee
If the Jiuberry Tranquil Dwell Portable Air Conditioning doesn’t win you over — you get every penny back. No questions, no justification. Full purchase price refunded.
⚠ Currently Available with Launch Discount
The official manufacturer site is currently running a launch promotion with 50% off. The unit costs £139.99 instead of £379 right now. The offer is time-limited.