Diary Of An ADI

A Driving Instructor's Blog

Hatice Sadir - a normal (but dishonest) womanThere was a story in the media recently about someone who attempted to cheat on the theory test by having a bluetooth device under a headscarf.

As usual, ADIs across the web forums and social media know more about the story than anyone else – even though they only just read it in the newspapers – and it has prompted the usual “ban the burkha” mob to mount their soapboxes once again now that Brexit has given them the necessary bravado.

The woman in question, Hatice Sadir, was Turkish. She spoke very little English, and had failed a test a few weeks previously. It appears that she paid someone £300 for a two-way bluetooth device including specially designed headscarf. She booked a test with voiceover through headphones, and this was therefore audible to whoever was on the other end of her two-way link, and they told her the answers as the questions were read out.

Test centre staff recognised her from her previous visit. They noted that she hadn’t worn a headscarf the first time and were suspicious at that, and the fact she finished the test very quickly – which they found unusual for someone with language difficulties.

You will note from the photograph of Sadir, apparently outside the court, that she appears very westernised. She has a tattoo on her arm in the fashionable mode. The fact that she is (probably) Muslim is irrelevant. However, in their versions of the story, The Sun and the Daily Mail have identified the “headscarf” as a “hijab”, as is their modus operandi these days.

Sadir, a mother of three, was just a very stupid woman who was desperate to get a licence. Her (probable) religion has nothing to do with it. The only thing I find annoying is that she got a suspended 20 month prison sentence, when she refused to identify whoever it was who was providing the service she paid for. It ought to have been 20 months in custody just for that.

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Flip-flops - the most inappropriate driving shoesWith the weather we’ve had recently, there’s a good chance you’ll have had pupils turn up half naked for their lessons ready to sweat all over your seats (one of mine has been bringing a towel to sit on after I ribbed him about wetting the seat). Then, five minutes later, they’re moaning about being too cold because you have the aircon turned on (assuming you’re not a tight-arse who refuses to use it).

One issue which comes up regularly throughout the year, though, is what they have on their feet.

At the most basic level, a new driver has got to learn how to control the pedals, and especially the clutch. To do that, they’ve got to be able to feel it – which they can’t if they’re wearing big, clunky shoes. Running shoes are probably the worst for this, because they’re specifically designed to absorb shock (and therefore any light touch on the pedals), but any kind of shoe with a platform is going to make clutch control harder. This is especially true if the pupil hasn’t driven before, and even more so if they’re one of the types who is going to have problems in this area anyway.

I had a pupil a few years ago who was one of the jumpy kind. One day I picked her up directly from work, which meant she had ‘forgotten’ her driving shoes. She was wearing platformed Doc Martens – literally, with a four inch chunky heel and bulldozer tread underneath. I abandoned the lesson after less than ten minutes before someone was killed, and drove her home. In a similar vein, I remember once seeing a woman get out of a Mini Cooper wearing massive goth boots with wedge soles that were at least three inches thick (below the knee, she was a ringer for Karloff’s Frankenstein). You cannot drive safely in those. Period.

I always advise pupils to wear flat soled shoes with a thin profile. Anything thick is going to make life difficult, and it drives me crazy when one turns up for their very first lesson in designer running shoes, with the extra thick sole and a concealed wedge heel.

Speaking personally, I absolutely hate it when they want to drive barefoot. My reasoning behind this is that I know from direct experience that you can stub your toe or even cut your foot on the pedals if you hit them in the wrong place at the wrong time, and it bloody hurts. Car manufacturers don’t seem to put much effort into ensuring the undersides of the pedals free from burrs or sharp edges. Furthermore, there is no way most people can brake as hard barefoot as they could in shoes. And if it’s more than half an hour since the car was last valeted, the floor mat will have grit on it, and the last thing you want is to have to execute an emergency stop in your bare feet only to discover something sharp stuck on your sole.

Having said that, I had one pass recently who drove barefoot. I let her do it (after telling her off the first time for trying to stow her shoes in the footwell) after I’d done my usual test in this situation: the Emergency Stop. If they can execute an Emergency Stop barefoot to the standard I expect, then they can drive like that if they want (though I still don’t like it). And she could. However, at the same time she had referred a friend to me who was in the same Halls of Residence, and she couldn’t. One day a few months ago, she came out to a lesson wearing huge furry slip-on slippers (‘why’ was a long story which I’m not sure I fully understand even now). She immediately knew they were not good for driving and asked if she could drive barefoot.

I said that I didn’t mind (because her friend did it), but I was concerned about how well she would be able to operate the brake in bare feet. I asked her to brake firmly while we were stationary and to tell me how it felt. She said it hurt, and she didn’t think she’d be able to brake hard if she needed to on the lesson. Problem solved, and we rescheduled – with the additional light-hearted warning not to come out with the wrong shoes again.

I can think of loads of examples where pupils had previously worn sensible shoes, then come to lessons wearing different though not necessarily inappropriate ones, and had a stinker – just because the shoes are different! Small differences can have a huge effect on some people.

Pupils with larger feet also need to be careful. Anything much above size 9 or 10 doesn’t work well if their shoes have long toe caps, because they’re likely to start catching on the cowling above the pedals. Winkle pickers are a no-no if you have large feet in many normal cars, and since they often have absolutely no grip (just a thin, shiny sole), the risk of the wearer’s foot slipping is also greater.

Very wide- and loose-fitting shoes – Ugg boots spring to mind – are also potentially dangerous, because if you try to slam on the brakes there’s a good chance you’ll make contact with the brake and gas pedals at the same time. And it does happen – it happens sometimes even with small-footed people wearing sensible shoes, so throwing Uggs into the mix is just asking for trouble. The same is true when someone insists on wearing some sort of hobnailed boot two sizes too big as a fashion statement – they’re too bloody wide.

Probably the most dangerous shoes for driving, though, are backless types. Mules, backless sandals, and flip-flops. It’s not necessarily anything to do with the heel thickness – though it can be if they’re platformed – but the fact that they can slip off. I mean, think about it. You can potter about as much as you like in summer wearing flip-flops or mules, but try to run and it’s 50-50 whether they will stay on, and 50-50 whether you end up flat on your face on the pavement or road. They present the same risks in the car if you have to move your foot suddenly to brake – with the additional chance that they will fall under the pedal and prevent you from depressing it fully. They could even get tangled up sufficiently to prevent you being able to brake at all. And don’t dismiss that out of hand – I once had a loop in a shoe lace double bow get itself completely over the clutch pedal (God knows how) so I couldn’t take my foot away or lift it high enough to declutch, and when I slipped the shoe off it swung under the pedal and stopped me declutching fully anyway. Shit happens, as the saying goes.

Strap-on sandals are not so bad, though the open toe arrangement still means you can catch your foot more easily if the sandals are particularly large and oversized (which many are these days).

And it goes without saying that trying to drive in high heels is just plain stupid. The heel messes up how you have to operate the pedals, and you cannot get anything like the same force if you really needed it. Many high heels have shiny soles with little grip, which makes matters even worse.

It isn’t illegal to drive barefoot, nor are any specific types of footwear banned or even mentioned in the Highway Code. The only reference is in Rule 97 (partial quote):

Before setting off. You should ensure that

  • clothing and footwear do not prevent you using the controls in the correct manner

However, DVSA has been quoted separately as follows:

Wear sensible clothing for driving, especially on a long journey. Suitable shoes are particularly important. We also would not recommend driving barefoot because you don’t have the same braking force with bare feet as you do with shoes.

My comments above are based purely on my own experience and knowledge, and they agree completely with this DVSA advice. And so do various other organisations.

I wear flip-flops and never had a problem

This stupid argument makes me angry – especially when it is coming from ADIs.

Everyone knows that if you have a set of expensive crystal glass goblets you shouldn’t drop them. If you do, they’re likely to smash. However, someone somewhere will undoubtedly have dropped one by accident one time, and it will have bounced on the carpet or the arm of a chair, and survived. This does not mean it is OK to drop or mishandle delicate glass goblets. It just means you were bloody lucky.

As I said above, if you try and run in flip-flops or mules, they’re easily likely to come off or send you sprawling (possibly both). The chances of that happening are roughly the same as they are of you getting away with it. If personal injury is one of the possible outcomes, then those odds are not good. If death for you or a passer-by were a possible outcome, they’re catastrophically bad.

I drive in high heels and don’t have a problem

There is no way you can drive as safely in high heels as you can with sensible flat soles. Period. It is a simple scientific fact based on the change to the way you have to apply leverage to the pedals when a high heel is extending and deforming your foot length. Having to brake hard in an emergency situation is going to be a lottery if there is the chance of your four inch heel making contact with the floor before you’ve got the brake on hard enough, or if it snags on the mat.

Remember the example I gave above, of the woman in the goth boots? Three inches of plastic increasing her leg length by 10% and suppressing all feeling of the pedals? Driving in high heels is no different – possibly worse – and anyone who suggests otherwise is a complete idiot, even if they have “always done it”. That’s the risk you’re takin each time you drive in heels.

Pupils will drive in those shoes when they pass

That’s their problem. Your job is to try and educate them in what’s right and what’s stupid while they are with you – not to encourage them in dangerous practices.

I advise all of mine to keep a pair of driving shoes in the car when they pass and not to risk it with heels. Beyond that, it’s up to them.

It’s not against the Law to wear flip-flops

Well, you’d probably still be arguing the toss even if it was. But the fact that it isn’t specifically against the Law doesn’t mean it is the sensible or right thing to do. That it isn’t specifically against the Law means that you doing it is your problem as you struggle with simple common sense. But if you’re encouraging others to do it, then you have become the problem.

But you let people drive barefoot

And I don’t like it. I only give in if they can prove to me that they can do an Emergency Stop properly. As it is, I can count on the fingers of one hand the number who have done it out of many hundreds I have taught. Quite frankly, I wish they would make it illegal to drive barefoot or in inappropriate shoes.

What shoes do your wear?

Deck shoes. I suggest to my male pupils they drive in something similar if they have any issues on lessons. I suggest to the females that ballet pumps with a firm sole are worth a try.

Why shouldn’t you put your shoes or bag in the footwell?

If you brake, whatever is down there will move forward. The only place for it to go is under the pedals. So if a kid on a bike rides out in front of you and your bag has moved under the brake or clutch, one of you will be in hospital (or worse) and the other will be up on a careless driving charge (or worse) and about 99% of the way towards becoming an ex-ADI.

Putting your shoes or bag in the footwell isn’t a problem

I have a tidy bag on the back seat of my car for a good reason. On more than one occasion during my driving lifetime, sharp braking has resulted in a bottle or book sliding under the seat and straight under the pedals. The design of the car footwell and the universal laws of physics guarantee that loose objects will end up there if you brake hard. Shit happens.

Storing anything in the footwell is dangerous. I regularly get people wanting to put their shoes, handbags, and even an umbrella down there. I simply won’t let them. Because I know from experience how dangerous it is.

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Another mass shooting in the USA. And just when you think that, this time, someone must start to take gun control seriously over there, you see this:

Texas Attorney General Ken Paxton, however, said gun control would probably not have stopped the attack.

He added that if a “crazy” gunman launches such an attack, there is no way that law enforcement officers could be there to stop it.

“The best way is to be prepared to defend yourself,” he told CBS News.

Look, you right wing, NRA-affiliated prat, if he couldn’t have obtained the gun in the first place just by showing his ID (and reports suggest he didn’t even have to do that because he bought it online), this almost certainly wouldn’t have happened – like with most of the mass shootings your country is famous for. How the f**k does anyone over there have the ‘right to bear’ an assault rifle? It’s designed to kill people. Period.

It is lack of gun control that has led to it, and lack of gun control which continues to fuel it.

And what Paxton has said is doubly stupid given that the situation is still ‘live’, and no one could possibly know enough about the shooter to determine his motives at this time, and thus conclude so absolutely that his actions weren’t preventable. Gun control would have likely prevented at least some of the 251 people who have already died in mass shootings in the US this year.

We don’t have mass shootings in the UK to anything like the level they do in the USA. Over here, it needs a special kind of psychopath with an especially deep sexual inadequacy to get hold of a gun and kill a lot of people all at once. In America, you can get a gun with your corn flakes, and if it then turns out you’re also inadequate, you’re already tooled up for what comes next.

And I woke up this morning to discover that as well as the 20 dead in El Paso, another 9 have been killed in a separate incident a few hours later in Ohio. The jackass this time was carrying a high-capacity assault rifle and extra magazines.

Gun control is the only answer. Not the full answer – but a damn sight better one than what they have right now.

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Driving Test SuccessI recently saw an ADI claim that theory test apps are no good because they “only cover 5%” of the possible questions. It’s yet more complete bollocks from so-called “professionals”, and is only true – and even then, only partially – if you (or your pupil) is an idiot.

The only app I recommend to all my pupils is Driving Test Success (DTS), which is published by Focus Multimedia. I have no affiliation with Focus whatsoever – though an agent of theirs did once contact me offering such a relationship, but I never heard from him again. The full version of DTS contains all the official DVSA revision materials, and unless they are telling lies, that means exactly what it says. They also do a free “taster” version, and that only contains about a third of the total questions in the official question bank (that’s about 30%, and not 5%).

Most of my pupils buy DTS if they haven’t already got something else – some will already have the DVSA one, which is perfectly OK, and which also contains all the relevant revision material. They all pass if they use either of these.

The important word in all this is “buy”. If you wanted to get hold of the raw bank of official questions from DVSA and use it or distribute it in any way, you’d have to pay. I know, because I have looked into it myself. You can register and get the question bank for free to play around with, but the moment you start giving anyone access to it you have to pay a licence fee per unit/user to the  to DVSA. If you wanted the Hazard Perception (HPT) clips, it’d cost you £800 up front just for those. You have to be approved to get the raw materials in the first place, and I asked if licensing charges would still apply if I only gave access to my own pupils. They said it would. So any official revision software would incur those same costs for the publisher.

Several years ago, I had advised a pupil to get DTS for his phone. I specifically said to get the one that cost £4.99, and not to download the free one, because it was just a trial version that didn’t have all the questions in it (at the time, it may well have contained only around 5% of the full question bank). He subsequently kept failing his theory test, and I was pulling my hair out as to why – I asked him about his school lessons, possible dyslexia and stuff, everything. He assured me there were no issues, and that he was getting 100% every time he did a mock test. After he failed for about the sixth time with a score that you could have bettered by guessing, something clicked, and I asked “how much did that app cost you?” He replied “oh, nothing. It was free”. I think my reply was something along the lines of “you prat! I told you that was a trial version”.

It turned out he’d been answering the same incomplete sample of questions over and over again (he said he wondered why he kept seeing the same ones). It was no wonder he was getting 100%. Once he bought the full version – with all the questions in it – he passed the next time.

ADIs who make stupid claims about apps only containing 5% of the questions must be of a similar mentality to that pupil. They expect free versions to be the full monty, and stupidly assume that when they aren’t then this must be true of all apps whether paid for or not. God only knows how they qualify as ADIs if they are so dumb. I figured out what “trial” meant the first time I saw it – particularly when there was the paid-for version sitting right next to it in the Android market, prompting the immediate question: why?

The only thing you need in order to pass the Theory Test is the DTS Bundle. It costs £4.99, and includes the Hazard Perception (HPT) clips. The official DVSA one is also fine and costs the same, though I haven’t used it in a long while.

There are some free ones which claim to contain all the questions, though those I’ve seen don’t have the HPT included. They contain advertising and “in-app purchases”. As I say, someone somewhere has to pay.

Frankly, for the sake of £4.99, and the risk failing the £23 Theory Test a few times because you didn’t have the right revision resources, you should stop pissing about and just buy it.

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Media manipulated test pass ratesA few days ago, the media was awash with reports about how the driving test pass rate had plummeted, and it was all because of the “new parallel parking manoeuvre” that had been introduced. It was a great opportunity for ADIs who have been against “it” from the start to give their two penn’orth.

Although the link above was from The Telegraph, the Daily Mail ran the same illiterate crap, and several others followed. Comic news site, Yahoo, even went so far as to blame the same “new” manoeuvre on a separate FOI request, which revealed one candidate took 21 tests in a single year.

It seems that in the world of newspapers, someone who has just been given their first job in journalism does one of these FOIs every year. I think it must be some sort of induction test to make sure they can fill in an online form properly. And every year, without fail, there is someone somewhere who has taken an ungodly number of tests before passing (and some of them still haven’t passed, even then). It is a separate statistic which is independent of how easy or hard the test is. It merely shows that just as some people are crap journalists, there are others who are crap drivers and perhaps ought never to be allowed to drive. Ever. But it is separate.

The really laughable part is the reference to this “new parallel parking manoeuvre” – all the more laughable since there are ADIs who have allowed themselves to be associated with the claims. Because there IS no new parallel parking manoeuvre! Even some joker representing a querulous organisation which, in a previous incarnation, specialised in stirring things, ranted about how “dangerous” it is without clarifying the glaring naming error (perhaps because he didn’t know himself).

What there actually is is a piss-easy manoeuvre which involves checking your mirrors and looking ahead to make sure it’s clear, pulling over on the right-hand side of the road, then reversing back a couple of car lengths without ending up on the pavement or on the other side of the road again, and finally driving off and going back over on to the correct side safely. It’s the kind of thing any 17 year old is going to be doing 5 minutes after he passes when he sees one of his mates on the other side of the road.

The manoeuvre is referred to as “pulling up on the right”, “stopping on the right”, or similar phrases. And it is not a “parallel parking manoeuvre”.

It’s only dangerous if people haven’t been taught to do it properly. Mine have to do it on busy roads in Long Eaton and with oncoming/passing/parked lorries on a busy industrial estate in Colwick, and the only problem I’ve had was when someone decided for reasons not even known to himself to turn the wheel on to half lock as he reversed and veered outwards (and since he didn’t notice until I showed it to him on the dashcam, it was probably best he was caught early anyway). A disproportionate number of tests seem to include it, and I thought they’d pull back on it after the original introduction – where virtually every test did it – but they haven’t.

The media has claimed that the pass rate has plummeted. They base this ridiculous statement on something like the graph at the top of this article – which shows the national pass rate for the last three years. I have carefully adjusted the axes to make it look as bad as possible, just like pretty much every journalist does when they’re talking about numbers. Yet it is only a little over 1% decline over three years. If you ignore the fact that life has been going on for more than the last three years, it looks like the pass rate is on a downward slope into oblivion – even if it would take over 40 years to get to zero at the rate it is going.

However, if you look at pass rates since the introduction of the driving test in 1935, a completely different story emerges.Official pass rates since 1935

I cut these data down to one approximately every 5 years up until 2007, and from there on the data are yearly. Because of that, and also because I started the y-axis at 20% instead of 0%, they look a bit more dramatic than they are (i.e. the right half of the graph covers 19 years, whereas the left half covers 65 years – imagine the 1935-2000 part stretched out to three times wider).

Something odd happened between 1975 and 1990, and between 1990 and 2000 (a rise followed by a fall). But since 2000 the pass rate has been virtually flat – hovering between 44% and 47%. It is currently at about 46%, and there are no blips or drops worth a mention (i.e. any changes to the test have neither improved or worsened pass rates to any significant extent).

As I said, the top graph shows what you can do if you don’t represent data properly, and the message that comes across if you’re an ADI or journalist who doesn’t understand data is both confused and wrong.

The only time the pass rate has been significantly higher than it is now was in a different era. No internet, no smartphones, dial phones wired to the house, two postal deliveries a day (one of them before you got up), bottled milk on the doorstep, outside toilets, bin men who actually carried bins overflowing with filth and tipped them in the back of a truck, anything up to 1,000 times fewer cars on the road, no motorways, no roundabouts, and so on. DVSA does itself no favours harping on about training standards being the issue when the pass rate is hovering around 45%. It’s just the norm, and has been for almost 20 years – and up to more than 50 years if you allow a few percent extra variance.

One thing is certain. The pass rate has not fallen (or risen) significantly for the last 20 years. And the proper graph clearly shows its not likely to change much in the next 20 either – unless some idiot forces it to. I try not to say bad things about them, but I’m sure DVSA is disappointed that the 2019 data point isn’t joined by an almost vertical line up at 90%, and will likely blame this on poor training again.

Oh, I almost forgot to mention. The reason I wrote this is that DVSA has had to send out an email correcting the false media stories.

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The Chillmax AirEarlier in July, I saw this thing advertised on TV. Then, the same evening, I was shopping in Asda and saw it on display. I am an idiot for things like this, and bought it on impulse so I could test whether it worked or not.

As a chemist, I know full well that if you want to cool a large space down effectively you’re going to need something that uses a special refrigerant. And from a practical perspective – where people are going to be in that space, and you need to cool for long periods – that is going to mean some sort of motor-driven compressor, a closed radiator filled with the refrigerant, and a big fan. Oh, and an exhaust pipe through the wall to get rid of the heat removed from the air, and a collection bucket for the moisture it takes out, because a proper air conditioner dehumidifies the air it cools.

Anyone who has used a normal fan will know that you only feel “cooler” if you’re sweating. That’s because the fan evaporates the sweat, and that has a transient cooling effect. Another feature of this is that if it is very humid, then you can barely feel any cooling effect because sweat can’t evaporate (I’ll come on to this later). This same evaporative cooling effect can even be used to freeze water – albeit in very small amounts (and if you’re lucky) – when you force diethyl ether (the stuff they used to use as an anaesthetic) to evaporate quickly. The evaporative cooling effect of different liquids varies greatly, and ether will cool down to a very low temperature if you do it properly. However, ether is both highly flammable and toxic, so apart from demonstrating it in the school lab (where I remember it from, along with the massive headache it gave me), it doesn’t have much practical application these days (though early refrigerators used it, which was spectacularly dangerous).

The Chillmax Air uses the evaporative cooling effect of water. The unit consists of a reservoir at the top, which you fill with normal tap water, and this drips down on to a radiator unit which has ten sideways-stacked fibre panels in it through which a fan blows air. The water evaporates from the fibre panels, and the evaporatively cooled air comes out through the front grille. According to the marketing spiel on the TV ad, you’d be forgiven for thinking you’re going to get frostbite if you sit too close. I knew this wasn’t going to happen – but I wanted to know just how effective the Chillmax Air was.

When I set it up and turned it on, the first thing I noticed was that the fan is quite powerful, so you get a good flow of air directed at you. The next thing I noticed was that the air did seem a little cooler compared with what my desk fan was blowing at me. It also felt different in another way, which I’ll also come to later. But the big question was how much cooler was the exhaust air?

I fired up my trusty data logger and left it in front of my desk fan for 30 minutes for the control data. Then I moved it and suspended it in front of the Chillmax for the same period of time. This is what it recorded (red line is the switch over point).Chillmax Air - temperature recording

The ambient temperature where I ran the test was about 26ºC (it rose by about half a degree because I had entered the room, turned on the TV and my PC, and so on). The Chillmax brought this down by about 2.5ºC (the blip at the end is where it had just run out of water and was starting to warm up again).

So, the Chillmax definitely cools the air that passes through it, albeit by a small amount. Let’s work on the assumption that it would be able to get the same 2.5-3.0ºC drop no matter what the ambient temperature was. It’s for you to decide if that’s worth the investment, but be aware that if the ambient temperature is 38ºC, pulling it down to 35ºC still means it’s damned hot.

But there’s a little more to it than that. I mentioned that the exhaust from the Chillmax felt different to what my fan was throwing at me, and not just cooler. If I was going to try and put a word to it, I’d say it felt softer. I knew what it was right from the start, but my data logger really showed what was happening.

This is the data for relative humidity recorded at the same time as the temperature measurement, above (red line is the switch over).Chillmax Air - relative humidity recording

As already explained, the Chillmax works by evaporating water on fibrous panels by forcing air across them. That water has got to go somewhere when it evaporates – and it comes out as a vapour in the cooled air. Well, most of it does. Some of it actually condensed on to my data logger and began to drip during my test. I have since discovered that it also condenses on the front grille and can drip periodically, so you need to be careful if you put it on a shelf with, say, your laptop underneath. This is especially true if you’ve set the grille (which is adjustable) to aim slightly downwards, which you probably would do if it was above eye level. And the fan is quite powerful enough to project the drips forward when they drop.

The ambient humidity in the room where I did the test was about 43%RH. The Chillmax sent that up to nearly 58%RH. The drop at the end is where the water ran out, and it is likely that it would have settled around 58%RH. And that was why the air from it feels softer – it’s very humid. When you turn the Chillmax on, you can actually see the vapour in the right light.

It’s this humidity of the cooled air which really brings into question whether the Chillmax is worth the investment. Most people will already know that you can have a hot summer day in the high 20s where it is comfortable and pleasant, and another – perhaps slightly cooler – one which is really sticky and sweaty. That’s because of the humidity, or water vapour in the air.

Air can hold water vapour, and the maximum amount that it can hold varies with the temperature. At low temperatures, air might only be able to hold a few milligrammes of water per kg, but at higher temperatures this can go up to nearly 100g per kg of air. This is generally referred to as the humidity, but the important measurement – and the one people are really meaning- is the relative humidity (RH). This is the amount of water in the air expressed as a percentage of the maximum amount it could hold. When the RH hits 100% (more or less the dew point, though there’s a bit more to it than that) at any temperature, then any additional water will condense out immediately. It’s why your car windscreen fogs up in winter as soon as you get inside because your breath and perspiration causes the dew point to be exceeded. But even at lower RH values you can still get some condensation if there are nuclei which promote it (such as data loggers and the grille on the front of the Chillmax). The main thing, though, is that at higher temperatures, high RH is uncomfortable.

The real problem with evaporative cooling comes with changes of temperature on already very humid days. If it is 30ºC outside and 90%RH, dropping the temperature by 3ºC will send the RH up automatically – possibly hitting the dew point even if no extra water vapour was added. But with the air already containing almost 30g or water per kg at 90% RH, and sending the RH higher by cooling a few degrees, the Chillmax is pumping out another 500g of water during it’s run time – and that’s likely to hit 100%RH immediately. On a hot and sticky day, you’re likely to notice dampness when using the Chillmax because of this (I noticed it even in this test). Furthermore, if the RH is increased when it is already high, evaporative cooling from your sweat is less effective, and you could actually feel more uncomfortable even though the air is a few degrees cooler.

Proper air conditioners remove water from the air they cool – so much so that the best ones have humidifiers in them to stop the cooled air from being too dry (in my car, for example, if I have the A/C on the lowest temperature setting my lips start to feel sore because they’re losing moisture, and other people say that it dries their hair out). Proper A/C units use a special refrigerant the same as you get in fridges and freezers, and they cool the air so much that the RH goes beyond the dew point and most of the water condenses out – that’s why you get a pool of water under your car if you stop with the air conditioning turned on in humid weather (or have problems with them icing up if they’re badly drained). It’s also why it is nice and comfy inside an air-conditioned car (apart from your lips) when it’s hot and sweaty outside, even if you have your A/C set at a normal temperature rather than deep-freeze mode most people use. Dry air feels crisp, whereas moist air feels… well, softer. Almost like a sauna if it’s hot enough. The Chillmax does the opposite of normal A/Cs, and adds moisture.

Aesthetically speaking, the Chillmax is a cube – more or less – about 15cm along each side. There are two buttons on the top rear, one which changes the fan speed to one of three settings (or off), with a blue LED for each, and another button that turns the night light on or off. There’s a flap on the top front through which you add the water. The radiator system is a plastic-framed insert which you access by pulling the front grille out. It slots in and out easily. You can’t replace the fibre inserts in the radiator (well, I think you could if you could get hold of them), but you can buy the whole radiator assembly from JML for £15. My only major gripe is the power cable. The jack plug that goes into the Chillmax is quite stubby and doesn’t go into the socket very far, so it is easy to dislodge it. However, the cable itself is quite long, and the  mains plug is a moulded UK type.

JML claims the Chillmax can run for up to 10 hours per fill, but this is undoubtedly on the lowest of the three fan speeds. At top speed, it runs out in less than three hours. To be fair to it, you do still get a noticeable cooling effect on the lowest speed, and since the water lasts longer then, less of it will be getting pumped into the air at any one time, and that might offset what I said about humidity very slightly – but it’s still being pumped out.  JML sells the humidification as a positive without relating it to the comfort relationship between temperature and RH, but note what I said above. If you want to cool down in humid weather, it probably isn’t just the temperature that needs to come down, certainly not a mere 3ºC drop, and definitely not if that means pushing high humidity even higher.

Update #1: I have now tested it in what I considered to be hot and sticky conditions. In actual fact, the only reason it felt hot and sticky was apparently because the temperature in the room was 3ºC higher than when I did it before. It was uncomfortable compared to the last time – the kind of weather that means you’re sweating even when sitting still.

Here’s the temperature log (red line again shows the switch over between desk fan and Chillmax.Chillmax - temperature log in hot and sticky conditions

The Chillmax still achieved a similar temperature drop to the initial test. However, the air did not actually feel any cooler blowing on my face. If anything, it was more uncomfortable, though this is a subjective comment. The graph for Relative Humidity below explains why.

Chillmax - RH log in hot and sticky conditionsThe ambient RH was similar to last time, but the Chillmax sent it up to about 70%. This is why there was no noticeable improvement in comfort – the small temperature drop was cancelled out by making the air more humid (i.e. sticky). The increase in RH was greater than the last time I measured it, and I can’t immediately explain that, though it may have had something to do with ventilation (there was no wind at all this time, though there was a breeze in the original test, and with the windows open some of the humidity would have been removed). Mind you, it also occurs to me that since the temperature was higher, the air was able to carry more moisture, and perhaps that had something to do with it.

You might find the Chillmax useful. It’s quite a smart little device – it’s not a Rolls Royce build, but it’s not badly made for what it is – and not that noisy (but you can hear the fan on the top speed). It certainly cools the air. A little, at any rate. Unfortunately, the increase in humidity that goes along with that cooling definitely seems to cancel it out out at higher temperatures.

A final note: the previous model used to be called the “Arctic Air”. I can see why they changed that!

Update #2: I tried it in the latest heatwave (33ºC outside on 23 July) and you can’t feel any cooling effect at all.

Update #3: Right! That’s it! That “latest heatwave” maxed at 38°C indoors on 25 July, and even now – 1am on 26 July – it’s 36°C at 50%RH and I feel The Devil biting my ass. The last thing I want is to send the RH up to 90% using the Chillmax to get the temperature down to only 33°C. God knows how I’m going to sleep tonight. So I have a proper air conditioner arriving tomorrow – watch out for a review of that.

Does it really work?

Well, it does cool the air by a few degrees, but it also sends the humidity up. So if it is already humid and sticky, the cooling effect is completely cancelled out by the extra stickiness. You might get away with that if your windows are open and there’s a through-draught in your house (or personal space), but if it’s also very hot you may not see any benefit at all.

It definitely doesn’t do what you might think it does from those TV ads. It would be fine if it just cooled, but the fact that it also humidifies is the main problem you’re likely to experience.

From my own use of it, I would say that it is a better humidifier than it is a cooler – especially when it is very hot, which is the last thing you want.

Will it cool more if I use ice water?

No. Evaporative coolers are not influenced significantly by the temperature of the water used in them. The temperature of the air that comes out depends on the temperature (and humidity) of the air going in, and the science of evaporation.

Can I use it to cool my PC?

Someone found this article on the search term “jml chillmax air for pc cooling”. If they mean what I think they mean, no, there is absolutely no way you want to be blowing damp air into your PC.

They might have meant powering it from a PC. The mains adapter is rated 5.0V at 1.8A, so assuming the Chillmax does draw 1.8A (and it probably doesn’t, as this is the maximum rating of the adapter) then your PC couldn’t supply that current from a USB port. USB ports are rated at 0.5A or 0.9A depending on the type. Dedicated charging USB ports can handle up to 1.5A, and although that’s a close call (the fan in the Chillmax looks like a computer fan), personally I wouldn’t risk trying to power it from a PC.

Can you get larger versions?

You can certainly get larger evaporative coolers. The working principle is that the larger the surface area of water, and the greater the airflow over that water, then the greater will be the possible drop in temperature at the front end. However, cooling effectiveness is influenced greatly by the RH of the air going in.

If the air is very dry, then a large evaporative cooler might be able to drop inlet air at 30ºC down by as much as 10ºC. However, if the inlet air is very humid, the temperature drop could be as little as 1ºC. In the UK, the realistic temperature drop you could expect on a non-humid day for a large cooler would be around 5-6ºC, but on a sticky day you’d only get about a 3ºC drop.

Suppliers of these devices say that they need good ventilation or extraction, and I would imagine that’s so the humid air can escape. If you’re evaporating more water to get better cooling on larger devices, you’re also producing a lot more water vapour.

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Audi embedded in houseA DVSA alert came through yesterday informing us that they’re investigating the possibility of introducing graduated driver licences (or something along those lines). Again.

First of all, let’s look at the facts surrounding this news (i.e. what’s actually in it, and not what the media headlines are saying).

  1. They’re only exploring the possibility. It won’t happen anytime soon.
  2. There will be a consultation before – and if – any changes are made.
  3. They are talking about new drivers’ “first few months on the road”.
  4. They don’t know exactly what – if anything – will be introduced.
  5. “New drivers” means everyone, and not just 17 year olds.
  6. Any changes would be for future new drivers.
  7. The impetus for this comes from the Government, and not DVSA per se.

Don’t forget that it took over 40 years to get learners able to go on the motorway, and even in my time as an ADI there were numerous “nearly” moments within different governments. Even the final kickstart took over two years to implement.

So why is the issue of graduated licences coming up once again?

Data show that 20% of new drivers have a significant accident within the first 12 months of passing their test, and it is that statistic which is being addressed. However, if we look at separate data, which has been reported many times previously, there is an enormous blip in the accident statistics where the following points are identified from individual cases of those involved:

  • 17-25 year old
  • male
  • rural road
  • on a bend
  • at night
  • more than one occupant in the same age group
  • excessive speed involved
  • no other vehicle involved

If you translate this data, it basically means young show-offs with little experience driving too fast for their skill set, distracted by their mates, and whipping the wheel round to take a bend they only saw as they entered it, then spinning off into a tree or field. Frequently, at least one passenger is fatally injured. Although males feature highly in these figures, females are still represented, where the distraction is often slightly different but equally stupid. This whole scenario is why insurance is so high for that age group.

It comes down to inexperience. Inexperience of driving, and inexperience of self-preservation. And whether you like it or not, it applies to more 17 year olds than it does 40 year olds – a) because there’s more of them, and b) 17 year olds are more likely to exhibit behaviours which compound their inexperience. The whole issue is about actual accidents and actual deaths. It’s not some random game to moan about because you think your son or daughter is an angel and shouldn’t be treated in a manner that you consider to be unfair.

I’ve mentioned this before, but many years ago I had what was then my best ever pupil. He was a smart lad, from a wealthy (-ish) family, high-achiever at school, pleasant (as was the whole family), and a quick learner. He was an excellent driver when he passed his test first time after only 23 hours of lessons. And he promised me he’d drive safely.

His mum wanted him to do Pass Plus, because she was concerned at his lack of experience – a sentiment I readily agreed with because he’d passed so quickly. Six weeks later – during which time he’d been driving in the beaten-up little Fiesta his mum had bought him – I was amazed at how far he’d drifted away from what I’d taught him. He was cornering too fast and taking chances when crossing the path of other traffic. I pulled him back during the Pass Plus and left him with some words of wisdom once it was completed.

Sometime after, I began teaching his then girlfriend, who his mum had referred to me. The girlfriend told me that he had already damaged his car by hitting a kerb cornering too fast (he hadn’t told me that), and that when he was out with his mates he would drive very fast, sometimes over 70mph in 30mph zones (he didn’t tell me that, either). I was concerned for her, but she said he’d never do it with her or with his mum in the car, because his mum would kill him if she knew. And I can promise you that he was in no way unique. Some of those I’ve taught since have made it absolutely clear how they’re going to drive when they pass. And they do.

And that’s why something has to be done. Far too many young people behave like this as a matter of course. They know full well they are in the wrong (which is why they hide it), but they do it nonetheless because it gives them street cred with the other monkeys in the jungle, and is the next best thing to sex for a 17 year old. Being inexperienced doesn’t enter the equation as far as they’re concerned. It’s no use pretending that your little darling doesn’t do it, because he or she almost certainly does to some extent. I even saw an ADI making this claim. Quite frankly, if a teenager is in rebellion mode – as many are – being the offspring of an ADI might even increase the likelihood of them behaving like prats.

So although I think DVSA isn’t addressing the root of the problem, it is at least trying to deal with the possible outcomes of that problem. Any restrictions placed on new drivers would at least give them time to gain some experience before they’re let off the leash, and the testosterone (or oestrogen) is able to kick in fully.

Not all young people are dangerous

Potentially, yes they are. They are inexperienced, and that alone is enough to lead to errors of judgment. Bad behaviour just compounds it.

When I was younger, going skiing every year was risky and fun, and resulted in a broken collar bone the first time I did it through going too fast when I was still crap. I discovered that snow-ploughing at speed (i.e. as fast as possible) over moguls on a glacier in Verbier with almost no surface snow down a black run is actually not as good an idea as I had originally thought. At the time, having the entire lift system shut down so mountain rescue could get me off the glacier and to the hospital, then being temporarily disabled and off work for a few weeks when I got back was a badge of honour. These days (and as soon as the following year, in fact), I would see it as bloody dangerous and wouldn’t be that stupid again – even though I’m a much better skier. Being unable to drive and off work now would be a royal pain in the ass, and enormously embarrassing. That’s what maturity and experience does to you.

It’s unfair to penalise only young people

They’re not. They are talking of penalising all new drivers. The fact that younger drivers would be most affected is a statistical thing, as is the fact that 20% of new drivers have a significant accident in their first year of driving.

I see older drivers driving more dangerously

That’s a separate issue. The one being addressed here is lack of experience.

My son (or daughter) doesn’t drive like that

This makes me laugh. Yes they bloody well do! Inexperience, by definition, applies to all new drivers. Furthermore, unless you are with them every time they drive, you haven’t got a clue what they get up to. I’ve lost count of the times some prat (often with “P” plates on) has pulled out in front of me or cut me up, and the only reason there hasn’t been an accident is because of my anticipation and reactions (both as a driver, and as an ADI using the dual controls). Those drivers could easily be your son or daughter. You have no knowledge of it and no control over it whatsoever. In my opinion, coming out with this statement is one of the contributing factors as to why there is a problem in the first place (along with letting them have an Audi or BMW as their first car).

Actually, that’s another thing. The only reason anyone buys an Audi (or BMW) is to drive fast, so a new driver who gets one is not going to be sticking to the speed limit or driving cautiously. The only time you’re likely to be stuck behind one being driven slowly is when the driver is texting or pissing about with the stereo. The rest of the time, they’ll be trying to get in front. You can argue as much as you want about that, but it is a simple fact. I see it every day.

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Shaun the SheepPeople often find the blog on something to do with sheep. The latest made me smile – it was “what should you do when passing through a sheep”. The mind boggles, but I know (I think) what they meant.

The word “sheep” isn’t specifically mentioned in the Highway Code in this context, but the following rule is the relevant one (it comes under “other road users”):

Rule 214

Animals. When passing animals, drive slowly. Give them plenty of room and be ready to stop. Do not scare animals by sounding your horn, revving your engine or accelerating rapidly once you have passed them. Look out for animals being led, driven or ridden on the road and take extra care. Keep your speed down at bends and on narrow country roads. If a road is blocked by a herd of animals, stop and switch off your engine until they have left the road. Watch out for animals on unfenced roads.

It’s happened to me before where I’ve rounded a bend on a country lane and the road is blocked by a herd of sheep being moved from one field to another (twice in 18 months, though I haven’t had one for a few years now). I’ve also come across sheep just wandering on the road in the Peak District, and one time a lamb had escaped from a field and was being chased by someone trying to recover it.

I’ve also encountered cows browsing on the bushes on the outside of their field (I’m not sure who shit themselves the most that time I came round a bend on a single track road – me, or the bullock that had got through a fence, a stream, and then a hedgerow to meet up with me). Then, of course, you have horse riders – the normal ones who give you a wave, and the ones with attitude problems who take racehorses out.

In the case of the sheep being herded, I stopped and turned off my engine (and had a quick chat with the farmer who was at the front, and who explained to me that the quad bike they were using was cheaper to run than a sheepdog). If they were just wandering around in small groups, I passed slowly, keeping my eye on them. In the case of the lamb, I stopped, then put my hazard lights on when I saw a car come over the brow of a hill behind me.

What should you do when passing sheep on the road?

Someone found the blog with this question recently. It’s from the theory test, and the correct answer is to slow down and drive carefully. In reality, though, stopping and turning off your engine is often the best course of action, so make sure that’s not an option if you see this question.

Should you report a sheep in the road?

Of course you should, if it’s running loose from a fenced field or on a main road (as opposed to being herded by someone), and clearly shouldn’t be there. Someone could get killed. Use your own common sense – I’m no expert on sheep, but I know if one’s meant to be in the road or not.

This doesn’t apply to extremely rural roads, such as in the Peak District, where there are no fences and sheep wander freely across roads. You just drive with care and deal with them as necessary.

Who should you report it to?

Assuming it shouldn’t be there – and bear in mind what I said about places like the Peak District, where sheep do roam across roads – I would either report it to the farmer (if I knew where the farm was), or the police (if I didn’t, or if there was a significant danger).

A sheep on rural road isn’t the same as one on the M1.

I’ve never had to report sheep, but I’ve reported cows on a few of occasions – all times, to the farmer.

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I originally posted this article in October 2015, shortly after I started using PayPal Here to take card payments from pupils. Before then, I’d been using iZettle, but I had an unfortunate experience with them which forced me to find an alternative. They eventually admitted they were in error, but it was too late and I had purchased and started using a PayPal Here card reader.PayPal Here card reader

Since 2015, I have taken more than £70,000 in card payments through PayPal Here. As time has gone by, the number of people paying me by card has increased, and right now I’d say that about 90% of pupils pay that way. The rest still use cash (occasionally, someone will block book and hand over up to £700 in notes), and a few use bank transfers (block bookings sometimes come in this way). I refuse to take cheques – if someone has a cheque book, they have a card, and I can read that instead.

The PayPal Here reader can carry out transactions via contactless, PIN, and swipe (though swipe is not necessary in the UK). Single hour lessons can be paid using their card by contactless (if pupils have them) but anything above £30 by card has to be by PIN. Contactless phone apps depend on the app they’re using, and many pupils use these to pay several hundred pounds with no trouble.

Since I began using it, PayPal has updated the app several times, and it is extremely convenient being able to sign into the app using my fingerprint these days.

The massive benefit of PayPal over iZettle is that the money from a transaction goes into your PayPal account instantly. When you transfer it from there to your bank account, for all practical purposes that is instant as well (it says it can take “up to 2 hours”, but less than a minute is typical). iZettle took nearly a week most times – and we’re talking a business week here, so Bank Holidays both here and in Sweden (where iZetlle is based).

How long do PayPal Here payments take to clear?

For all practical purposes, they’re instant.

When you take a card payment either by chip & PIN or contactless, funds are instantly transferred to your PayPal Here account. You can leave them there, or transfer them to your bank account whenever it suits you – either from the app or from PayPal on your computer.

My only minor gripe is that you have to transfer the money manually – you can’t set it to go straight into your bank account. It’s on my wish list.

How much does the card machine cost?

Under £50 right now – often less if they’re doing an offer. I have three of them as a result of offers just so I have backups, though I am still on my first reader.

Is there a monthly rental fee?

No. You buy the card reader outright and only pay a fee per transaction.

How much do they charge per transaction?

It’s 2.75%. For each £25 lesson paid for by card, you “lose” 69p.

PayPal takes 23p for each £1 you take

NO. THEY. DON’T.

I saw some clown state this recently, and it’s bollocks. On a £25 lesson, the fee is 69p.

Other card reader vendors have lower fees

I’m not saying you must use PayPal. Just be aware that other vendors’ fees are often on a sliding scale (iZettle’s was),  and you only get the lower rates if you take more than a certain amount per month – which for an ADI is often quite high. I triggered iZettle’s lower rate fees a couple of times, but the lower rate only applies to takings above the threshold.

For example, if there is a threshold at takings of £5,000 per month, and you pay 2.75% up to that, and 2.5% above it, then if you take £5,500 in that month, you pay 2.75% on £5,000, and 2.5% on £500. To get any real benefit, you’d need to be taking £10,000 per month or more. Small multi-car driving schools might benefit, but a self-employed ADI wouldn’t.

SumUp has a fee of 1.69% per transaction. Yes, that’s less than PayPal’s fee. In a typical year, with SumUp you’d be paying £634 in fees. With PayPal you’d be paying £1,030. I like PayPal (and a lot of pupils use it anyway), and think the extra I pay is worth it. That’s just me.

Some vendors have no fees

And they keep the money longer to get interest on it to cover their costs or charge a rental fee. There’s no free ride when it comes to clearing card payments, and someone somewhere pays for it.

The charges are a rip off

Fine. Keep taking cash.

You’re not going to get away from transaction charges if you also want a decent service. A fee of 69p is nothing on a £25 bill. All you have to do is increase your prices slightly and you’ve covered the fee, anyway.

But I can save money if I don’t have to pay transaction fees

As I say. Fine. Keep taking cash. You probably also believe your car isn’t an overhead because you own it (it is), and that if you don’t have to pay a franchiser then you’re better off by the whole franchise fee (you’re not). A card fee is an overhead, that’s all.

I can’t see the point of taking card payments

Fine. Keep taking cash. It does seem to be the older ADIs who think like this, though.

For me, from the day I first became an instructor, the ability to take card payments was on my wish list. As years went by, having to carry lots of cash around (sometimes, a heck of a lot) and dozens of cheques – and make frequent trips to the bank – was becoming a major headache. Bank branches, especially convenient local ones, are an increasingly endangered species, and with parking fees and lost lesson time, and cheques (which are useless to you until they’re banked, and some weeks, every pupil would pay by cheque), it was more like an atomic migraine than a headache. There is a business cost associated with that, which is proportional to how often you have to go to pay money in. With cheques especially, I’d only have a cash flow if I went to the bank. I’d been waiting for something like PayPal Here or iZettle – and there are others – to appear, and got in on the ground floor.

What about cheques?

What about them? No one has attempted to pay me by cheque for at least 4 years now (though they only did before because it was either that or cash). A couple of new pupils have asked initially if I take them, but when I point out the card machine and the fact that everyone has a card even if they have a chequebook (otherwise cheques are pretty useless), it’s never mentioned again.

I can take pupils to a cashpoint

Good for you. I, on the other hand, don’t need to. The card machine becomes the cashpoint, so it’s more convenient for me and more convenient for them. And that is certainly not going to affect their opinion of me in a negative way. Of course, if I insisted on frog-marching them to a cashpoint… who knows what they might think?

Is it of any benefit to take card payments?

As I said, it has saved me a lot – in monetary terms, and in terms of my sanity.

But another benefit is less tangible. Some pupils might be impressed if you pull out an iPad and have a glitzy demonstration video to get some point across. Believe me, many more are impressed when you tell them you can take card payments – even more so when you actually take a payment in front of them and they get an instant texted receipt. This might become less true in the future as the dinosaurs gradually die out, but right now it works in a highly positive way.

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I got an email tonight from the Food Standards Agency (I’m signed up to alerts). It’s amazing how many recalls are issued each week – they’re mostly for bits of plastic or salmonella contamination, though many are labelling issues where something in them isn’t declared on the label.

The one I received tonight was of the latter type. The Co-op is recalling something called a “Veg Taster”.

Because of “undeclared fish”!

I can’t find out what a “Veg Taster” is, and I’m certainly not going out to buy one. But the name suggests that it is suitable for vegetarians. They do “Fish Tasters” as well, and the undeclared fish in the FSA alert involves salmon, so you can sort of half guess how it happened.

Joking aside, though. It could be a problem for anyone with a fish allergy.

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