Verdict

Pros

• Handy blackboard feature
• Concealed door handles with seal-release
• Supremely quiet
• Consistent temperatures keep food fresher for longer
• Great fail-test results

Cons

• Tall reach to the control panel
• No light in freezer compartment
• Freezer runs a couple of degrees too cool
• Blackboard feature comes at a high price

What is the Miele KFN 29233 D BB Blackboard?

For those who have struggled to find a piece of paper to scribble down that vital milk reminder or phone number, Miele’s KFN 29233 D BB has the answer. Not only is this top-spec frost-free fridge freezer bristling with Miele’s latest technology, but both doors feature a hard-wearing matte blackboard finish – perfect for jotting down reminders. Using a supplied liquid chalk pen, you can write notes, jot memos or doodle a Picasso while grabbing the OJ.

At over 2m tall, this Miele offers as much chilling capacity as writing space, is A energy efficient, and offers networked performance monitoring too. Can we stop doodling long enough to find out if it’s any good?

Miele KFN 29233 D BB Blackboard – Design and Features

Comfortably proving the adage that some of the best ideas are the simplest, meet the “Blackboard” special edition of Miele’s KFN 29233 frost-free fridge freezer.

The trendy matte-black finish on both doors isn’t just for show; it’s a hard-wearing blackboard surface ready to accept shopping notes, scribblings, muses and inter-family messages of the old-school written variety. For the more traditional, this fridge is also available in a stainless steel finish for £150 less.

Ironically, the matte-black finish is truly lush, even if you don’t want chalk all over it. The matte effect is highlighted only by subtle Miele branding; the temperature and control display is hidden away behind the upper door. This gives the errant scribbler or OCD memo-maker plenty of space for easily erased missives.

Regular stick chalk will work, but there’s some danger of scratching the finish, so Miele recommends liquid chalk markers instead. One white marker is supplied, but myriad third-party chalk markers are available in various colours and nib styles for the truly creative.

It works seamlessly, too, giving a solid white-on-black effect and is easy to wipe clean with a dry cloth or a damp one when things get really messy.

Related: Best Fridge Freezers

On the inside, this model makes no secret of its flagship aspirations and top-spec billing. On the door frame at the very top is a subtle blue display with touch controls, and bright white LEDs illuminate the refrigerator compartment.

The lamp housing is neatly integrated into the roof of the unit, and it’s set well forward in the compartment to ensure that a full top shelf doesn’t put the rest of your fridge contents in the shade. The visible Dynamic Cooling fan outlet at the top promises optimum circulation of cool air, and all of the shelves and storage bins are dishwasher-safe.

There are two key features at work that deliver the fridge compartment’s outstanding 260 litres of storage space, summarised in Miele’s marketing bumf as an “XL interior”.

The first is high-tech insulation, which keeps the fridge walls thin, and the second is added depth. At a total of 675mm deep, the main body of this fridge-freezer is about the same depth as a standard 600mm worktop, with the doors protruding some 75mm beyond that.

This has allowed Miele to hide the door handles, complete with seal-release mechanism, on the side of the doors. The result is a seamless look to the door fronts and very smooth, effort-free door opening. It’s going to stick out a few inches further than your standard worktop, of course, and in the blackboard finish it will certainly be something of a visual centrepiece in the kitchen.

Miele KFN29233D BB Blackboard – Capacity and Layout

The KFN29233D delivers close to the absolute maximum amount of total cooling capacity you can squeeze into a 60cm-wide fridge freezer without needing a ladder to get to the top shelf. For vertically challenged users, that may already be the case. You get a whopping 260 litres of chiller capacity and 101 litres of freezer space.

The Blackboard has the fridge-freezer equivalent of luxury furniture throughout too. The increased depth over standard refrigerators is ideal for holding large baking trays. You get a full complement of five glass shelves, a bottle rack, two chiller drawers and four full-width door pockets. The smaller central drawer is ideal for smaller items or trays of produce, while the lower “Daily Fresh” bin is truly cavernous and features a humidity control slider. It’s very tall, and deep thanks to the extra-depth appliance size and the raised lower door pocket. You can easily get a week’s worth of veggies for the family in here, although the potential for losing the odd shallot or small courgette in all that space is fairly high.

The freezer section is equally deep front-to-back, so you get three large-capacity drawers, all of which pull in and out with ease. Between the drawers are glass shelves allowing you to remove the drawer itself and simply stuff the shelf space for even greater frozen capacity. Got something really large to freeze? Then simply remove the upper shelf as well for enough space to accommodate, well, a whole lamb or a side of beef.

What this freezer is lacking, considering the KFN29233D’s price ticket, is any sort of illumination.

Up top, the control panel is neat and clean looking, but it does require a look at the manual, as it’s not necessarily intuitive – doubly so if you’re teetering on a kitchen stool to reach it. However, dig into the menu and you get the usual selection of superfreeze and supercool features for chilling down fresh food, a quickcool timer to stop the Prosecco icing up when you chill it down in the freezer, and a party mode. This sets both the fridge and freezer compartment to their lowest setting to speed-chill party foods and combat the doors being opened frequently.

In addition, there’s a low-energy holiday mode, a minute-minder timer for monitoring processes like chilling dough, and a Sabbath mode. In this mode you can programme the machine to turn off interior lighting, disable audible and visual alarms and turn off the temperature display for the purposes of observing religious festivals.

Accessories supplied include a pair of freezer pack ice-blocks, an egg tray and an ice cube tray. As an option you can purchase a Miele Active AirClean activated-charcoal air filter system to ensure that odours from strong-smelling foods don’t taint other foods – a must-have for families with the odd left-over vindaloo. For the nearly £1500 asking price we would’ve expected the Active filtration as standard, though.

Miele KFN29233D BB Blackboard – Noise Levels

Miele has gone to some length to make the KFN29233D as quiet as possible, installing sound-deadening materials in critical areas, running a sound-optimised refrigeration cycle and using a very quiet motor. Miele calls this its “Silence System” and the result is a claimed 38dB sound output on the energy label, which is as low as refrigerators get. So low, in fact, that we had to test the sound output in the wee hours of the morning, as background noise from a distant road is actually louder.

The Miele’s compressor cycle is about an hour long, but the machine is only running something like 5-10 minutes of the hour. So for 50 minutes of every hour it’s actually genuinely silent. In the time it’s running, the sound is barely audible and, with our test equipment struggling to get a fix, we measured between 37dB and 39dB, comfortably backing up Miele’s 38dB figure. That is really very, very quiet and in an average home you simply won’t hear it at all.

Miele KFN29233D BB Blackboard – Performance

We loaded the fridge with 0.5kg of mixed fresh food per 10 litres of fridge capacity, and the freezer at 1kg per 10 litres of space. This including 2 litres of room-temperature water to represent fresh-to-frozen food such as freezing a beef joint or a fresh whole chicken. We constantly monitored and recorded the temperature on each shelf and in each drawer of both compartments, plus the water sample, over the course of several days of testing. The appliance was kept at an ambient room temperature of 19ºC and the doors opened for 15-20 seconds half a dozen times per day.

We set the fridge temperature thermostat to 4ºC, but the tall compartment offers a relatively wide range of temperatures depending on which shelf you place food on. The lower Daily Fresh drawer came in coolest at 3ºC, the shelf above and the middle drawer at an average of 4.5ºC, the second shelf from top at 6ºC, and the very top shelf averaged close to 8ºC. This spread gives you plenty of scope to choose shelves to suit foods, with your veg, fish and meats at their best lower down, cheese and fruits in the mid-section, and non-critical foods like jars at the top.

The spread is perhaps a little wider than absolutely ideal – 3-6ºC would be perfect – but it’s not far off and the consistency of the temperature is superbly even. All probes in the refrigerator measured just /-1ºC either side of the average temperature, with no high spikes or big drops close towards freezing that may damage soft fruits. Consistency of temperature is arguably more important than absolute temperature in terms of keeping your food fresher for longer, and the Miele scores very well in this respect.

Down in the freezer the results were also very good for consistency and the spread of temperature was much narrower too. The difference in average temperature from the top drawer to the bottom drawer was just 2ºC, albeit -20 to -22ºC… somewhat cooler than the -18ºC we set the thermostat at. Our room-temperature 2 litres of water chilled down below freezing in a very quick 14 hours and remained at exactly -22ºC over the several days of testing.

The top drawer did ‘bounce’ over the compressor cycle a fair bit – between -18 and -23ºC – but the lower drawers remained very stable, within a degree of the average temperature either way. All very respectable results. Given the high-tech insulation and A efficiency rating it’s perhaps no surprise that the KFN29233D passed our power-fail test with flying colours. The food sample raised just 5ºC to -17ºC, and the maximum air temperature didn’t get any higher than -12ºC. Frozen food in the KFN29233D will be comfortably safe even if the power’s off for over 16 hours.

We were unable to test the networking abilities of the KFN29233D, as the Miele@Mobile service wasn’t registering new UK users at the time. The app’s demo mode indicated a basic display of fridge and freezer temperatures, and the ability to toggle superfreeze and supercool modes. 

Miele KFN29233D BB Blackboard – Running Costs

Miele’s rather cold freezer running at -20 to -22ºC rather than the -18ºC set on the thermostat will undoubtedly have a slightly negative effect on running costs, as it simply needs more energy to keep things colder – or, more accurately, colder than the ambient air temperature of your kitchen.

Yet, you don’t get an A energy label rating without being pretty darn energy efficient, and this Miele will cost you very little to run indeed. Based on our tests we calculate it would use approximately 180kWh per year, which is very close to Miele’s claimed 174kWh. With electricity averaging around 15p/kWh that’s comfortably less than £30 a year for a whole lot of cooling capacity.

If the freezer temperature thermostat was a little more accurate in keeping the freezer at -18ºC this would be even less. A hot kitchen or big family opening the doors all the time will increase running costs, of course, but the Miele’s A efficiency should keep the effect to a minimum. Moreover, you can always chalk “KEEP THE DOORS CLOSED” on the door in big letters.

Should I buy the Miele KFN29233D BB Blackboard?

The KFN29233D Blackboard is everything we’ve come to expect from Miele’s flagship refrigeration. It’s incredibly energy efficient, offers consistent temperature and is packed with nice touches like the concealed handles and dishwasher-safe storage bins.

Its extra front-to-back depth does mean it will stick out from a typical worktop by a few inches, but the benefit is about the biggest total cooling capacity you can buy in a 60cm-wide fridge freezer. Add to all this the really useful blackboard finish and Miele’s chalked up another success.

Verdict

A fantastic premium fridge freezer with a genuinely useful blackboard finish.

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