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Silver Birch Dropping Leaves Early

It’s now pretty much mid-Summer. Earlier this week we had the hottest day on record – in Nottingham, it reached 39.6°C, which is much warmer than it was even in 2018. I have been watering my tree heavily (no hosepipe ban) and it is lush green. However, I noticed that a neighbour’s Birch has sprays of yellow, and while I was out on lessons today a lot of roadside Birches are yellow or even brown (like they were in 2018).

The following is the original article… but remember: water, water, water. And feed!

Our Silver Birch in June 2017Back in 2014, when I originally wrote this, our Birch tree suddenly began to produce a lot of yellow leaves in mid-June. After a lot of research I managed to figure out the possible causes and the remedies. That was the purpose of the original article.

However, 2018 threw up a new issue. It turned out to be the hottest year on record, but even before we found that out people will remember how hot it was, and for how long it stayed like that. My tree once again began to show a few sprays of yellow fairly early in the season.

The article becomes popular each year, firstly in late Spring and early Summer, then again later in the season closer to Autumn.

In 2014, I identified the following as likely causes of premature yellowing:

  • nutrient deficiency
  • iron deficiency
  • manganese deficiency

After the 2018 heatwave, I further identified lack of water as a major factor. With hindsight, it may have also been a factor in that 2014 season, but nothing compared with 2018 for prolonged heat and lack of rain.

When I first experienced yellowing back in 2014, I initially thought my tree was dying. Googling for an answer was pretty much useless, because most of the technical advice is American and focuses on the Bronze Birch Borer (a beetle that feeds on white birches), which isn’t known outside of  North America. But somewhere in among the advice, I came across a simple comment – and I don’t recall where I saw it now – that made a lot more sense.

In a nutshell, premature yellowing/leaf drop can be caused by nutrient and iron deficiencies in the soil. This comes about over a period of time as fallen leaves are swept up each year and sent to the tip, so none of the nutrients are returned to the soil. Consequently, the soil becomes depleted of them.

Birches are ericaceous – lime-hating – plants, and prefer a slightly acidic soil. As such, you need to feed them using ericaceous fertiliser. I first used Miracle-Gro solid fertiliser, intended for Azaleas and Rhododendrons (also lime-hating), but a couple of years later switched to Doff liquid feed so I could use it in my Access Irrigation Static Dilutor. I also got hold of some Maxicrop Seaweed Extract, which is also liquid, and watered that in at the same time.

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My original problem showed itself as canary-yellow leaves, either in sprays, or randomly dotted throughout the canopy. On closer inspection, some of the leaves looked like those in the photograph here.Leaves suffering from chlorosis

This is known as chlorosis. Leaves are usually green because they contain chlorophyll – and chlorophyll is green. Chlorophyll is what allows plants to convert light energy into sugars that they can use as food through the process called photosynthesis. Plants use iron to produce chlorophyll, so if there isn’t enough iron in the soil the tree can’t make enough chlorophyll, and you get yellowed leaves. The tree compensates for being hungry (if it hasn’t got chlorophyll it can’t make food for energy) by going into shutdown and shedding those leaves. And you may also find that new leaves are small and misshapen when chlorosis is the issue.

You can easily treat chlorosis using sequestered iron (or seaweed extract). Being ‘sequestered’, the tree can suck the iron up and use it right away. A longer term solution is to use iron sulphate lawn feed, which also slightly acidifies the soil over time.Close-up of leaves suffering from chlorosis

I also bought some manganese to water in the first time, but I am not sure how relevant that was. I used it for a couple of seasons, but stopped. Each year, I simply feed the tree once or twice a month between March and September using fertiliser and seaweed extract.

Note that none of these problems are confined to Silver Birches. All trees and plants can be affected by nutrient deficiencies, and you simply have to deal with the problem using the appropriate, easily purchased treatments.Close-up of our tree's leaves in June 2017

In that first season, a single application of fertiliser stopped the leaf drop almost immediately. Once the already-yellow leaves had fallen, the tree remained green until Autumn, and even threw out some large new leaves and fat catkins. It obviously liked what I had done to it, and I continued doing it from June until September every few weeks.

Everything was fine until the hot summer of 2018. You might recall that the prolonged heatwave began quite early, and by the end of June I was again noticing a few sprays of yellow. I wasn’t a nutrient issue this time – I was feeding the tree regularly – but I’d already guessed the hot weather might have something to do with it, and a bit more research showed that heat stress in trees is a real issue, and Birches are highly susceptible to it.

It turns out that lack of moisture in the ground combined with prolonged high air temperatures causes trees – and especially Birches – to become stressed, which again triggers them to go into emergency shutdown by shedding leaves.

My research provided two options for getting water down to the roots (which fortunately, in the case of Birches, is quite shallow). One involved hammering at least half a dozen hollow spikes into the ground around the tree and dripping water directly down to them. I decided against that on the basis that a) the ground was already as hard as iron plate, b) anything which sounds so simple (i.e. hammering a hollow plastic spike into the soil) was going to turn into a nightmare of split plastic, only being able to get part way down, and discovering chunks of bedrock I didn’t know were there, and c) having these things poking out of the lawn would look bloody awful even if I got them in (and even worse if they only went in part-way). The easier option was to commence heavy-watering immediately – basically, to run the sprinklers for hours at a time every  night.

That method fixed the problem in less than a week.

With hindsight, it is quite possible that lack of moisture was a contributing factor back in 2014, and my feeding routine would have dealt with that automatically (though I did have chlorosis). But in 2018, it was definitely just the result of too little moisture around the roots.

So, to summarise. If you experience premature leave-yellowing, the very first thing you should do is water like crazy. Don’t worry about over-watering too much – Birches like wet soil, which is why they grow near streams. Just don’t turn your garden into a swamp. While you’re doing that, buy some ericaceous feed and seaweed extract, and get that into your soil as soon as possible (how much depends on how big your tree is).

Can you rescue leaves which have turned yellow?

No, probably not. I suppose that chlorosis could be reversed if you caught it early enough, but if the leaf is dead and the tree has triggered its shedding mechanism, you’re going to lose them.

The important thing is that by feeding and watering the tree you can stop any further yellowing – and believe me, the first time you do it the effects will be quite noticeable within a short time.

Do you have to keep treating the trees?

Yes. If you don’t, the problem just comes back once the tree has used up what you’ve fed it, especially if you bin the leaves again the following autumn. Huge trees will suck up all the nutrients and water, and if you’re raking up and binning the leaves each year (or if the soil is dry and there are no prolonged periods of rain) nothing gets returned to the soil.

How often should you feed?

Treat them once or twice a month from March until September. And water regularly.

Can heat and drought cause them to lose leaves?

Yes. If they are stressed you may get them dropping leaves. In extreme cases the leaves can go brown and the tree can even die. It’s a good idea to water them deeply during hot, dry periods. Once or twice a week should be enough, though more frequently won’t hurt if the dry period is prolonged.

Remember that after a period of drought (or prolonged dry weather) it needs an extended period of rain to wet the soil again, especially deep down. A few heavy downpours won’t do it, and you will still need to help things along.

Will a Birch recover from drought?

It depends on whether the drought killed it or not. A reader wrote to me in 2018, mentioning that his tree had lost its leaves, and I advised that the only thing he could do right then was to feed and water – and hope for the best. He wrote to me in 2019 to tell me the tree had started to rock in the wind, and that a tree surgeon had subsequently declared it dead, and had had to remove it. Apparently, the roots were rotten.

There’s no way of knowing if it was just the drought that did the damage. The tree may have been weakened by not feeding and watering over previous years, and the drought was just the final nail in the coffin. But the 2018 heatwave certainly caused problems.

Is there any other way to deal with the problem?

You have to get nutrients and iron back into the soil. And you need water in order for the roots to be able to access those nutrients. Yes, you could use your own mulch or bought compost, but obviously this is not so attractive in a normal garden (removing it is what got you here in the first place). It would also take longer to have an effect. But it would still work, given time.

When do Birch trees normally start to shed their leaves?

In the Autumn! In the UK this is from around September-October, and the onset varies up and down the country. It often seems triggered by a noticeable drop in night time temperatures. The leaves will begin to fall from that point – very lightly at first, then increasing as the yellowing spreads.

Why do birch trees drop leaves so early?

They don’t. They drop them in Autumn, like all other trees which shed their leaves each year. If yours is turning early, you may have a problem.

How do you apply these treatments?

You make up the required solution as directed on the pack, then water it into the area specified. I use a combined watering/fertilising system, which I have written about separately. However, you can use a watering can and hosepipe/sprinkler as necessary. Note that if the ground is dry, a watering can won’t get the nutrients down to the roots, so a heavy watering is essential.

Why are fallen leaves sticky?

You’ve probably got greenfly! Specifically, the birch aphid, Euceraphis betulae. They feed on the European Birch, Betula pendula, and they increase in number during warm and dry weather. Aphids secrete honeydew as they feed, and that’s the sticky stuff you’re seeing. Apparently, you can get different species of greenfly that feed on specific trees.

You can kill them with a soap/water mixture, though no one has ever been able to tell me precisely how you apply that to a 20 metre high tree. And the same goes for any chemical method relying on direct contact. An alternative solution is to introduce predatory insects – something that eats aphids. The best one is the Ladybird larva, and you can buy them online. There are other predatory insects you can buy, too.

My tree is losing branches and twigs

If the tree is weak then it is understandable that twigs and small branches might fall off. Once they’re stronger this will stop. In any case, if it is windy, a few dead twigs are bound to fall off. It’s just nature – and birches also have a fungus which can cause small twigs to die and fall.

In the Spring, Crows can also be a problem if they’re nesting nearby. They are very, very selective in their choice of twigs for the purpose, and they will tear off dozens until they get the right one. It’s nature, so we don’t worry when they’re using ours for their twigs.

When do birches start to show leaves?

In Spring, obviously, but the precise date varies depending on both the tree and the weather. In 2019, they were about a month earlier than 2018 in the UK. Mine is usually showing leaves sometime during April each year.

I’ve got catkins but no leaves

Someone found the site in April 2018 with that query. You’ll probably find that in a couple of weeks you’ll have lots of leaves. As I have said in this article, I start feeding mine from March onwards. Leaves start sprouting a week or two earlier than my neighbours’ trees, and the foliage on mine is usually much denser. The catkins often come before the leaves.

Are the leaves changing early this year?

This was a generic search term used to find the blog in mid-July 2017. The short answer is no, they are not – not in July in the UK, anyway. They change towards the end of September in the UK.

Do Weeping Silver Birches lose their leaves in Autumn?

Yes.

When do Silver Birch leaves go all brown?

They don’t. The leaves should go yellow and fall off in the autumn.

I had quite a few visitors from this search term in 2018, and when I looked it up it seems that extreme cases of chlorosis and heat stress can result in leaves turning brown (see this supplementary article). It could also be a disease or infestation which you could treat, but the tree itself might also be dead – especially if it has been having any of the problems I mentioned above over previous years. Best to call in the experts.

Does this advice only apply to Silver Birch trees?

No. Chlorosis can affect many plants, and lack of nutrients is a universal issue. You might need a different fertiliser to address any nutrient problem, but iron will likely fix chlorosis. Lack of water can kill virtually any plant.

A Couple Of Recent Passes

Rear-ended by an idiotSometimes you couldn’t make it up.

About a month ago I was rear-ended by some idiot at a pedestrian crossing. As a result, my car went in for repair and I had a replacement/courtesy car supplied – which was totally different to my normal car. It took me a few days to properly figure out how it worked (absolutely everything was controlled from a touchscreen system). It scared some of my pupils shitless.

I had one pupil whose test was approaching. She was away with the fairies as far as lane discipline was concerned – she simply had little or no awareness of them when she was driving. But we’d already postponed her test once as a result by over six months, and to be fair I had managed to improve her a lot. But I still wasn’t 100% happy.

But she didn’t like the substitute car. She texted me and told me she was going in her own car as a result. I fist-pumped and shouted ‘yesss’ when I got that text. We did a few more lessons and I made sure she had everything she needed to give it her best shot. And she only went and bloody well passed! Quite a high number of driver faults, it has to be said, but at least my badge wasn’t involved.

Then, I took on another pupil. He’d been taught by his parents and his driving was outstanding – seriously good. The only significant issue was the manoeuvres, none of which he had been taught, and his theory test (which he hadn’t done). So I got him to book his theory, and started covering manoeuvres with him. We did four lessons, during which he passed his theory first time, and then I got him to book his practical – which was in November.

I got a text a couple of weeks ago and he’d got a cancellation date. But it coincided with another test I had booked (ironically, I turned up for that one today and then discovered DVSA had cancelled it and moved it to August), and it was at a test centre outside of Nottingham, which I didn’t cover. So we agreed he would go in his own car with his mum. My only concern was we hadn’t polished the manoeuvres, but I pointed out that apart from that he had a bloody good chance of passing.

And he passed with a clean sheet! Zero faults. In a place he’d never driven before.

His parents are singing my praises and have already referred someone to me as a result. I’m happy with that, of course, but I am quick to point out it was his parents who actually taught him (and the whole family is really nice) – I just polished a few rough bits, aided immeasurably by the fact he was an outstanding driver. And he’s going to do Pass Plus with me.

So, apart from not getting official DVSA credit for the passes (especially the clean sheet), I’ve avoided the higher faults of one against my name, and got what is likely to result in a lot more work from the other.

Being an ADI is fun. And complicated.

Review: JML Chillmax Air – Personal Space Cooler

The Chillmax AirIt’s 2022, and with the July heatwave traffic to this has gone through the roof yet again since it’s original publication in 2019.

Note that this article applies to the InstaChill, Chill Tower, and any cooling device that costs under £100 and claims to just run ‘on water’.

In quick summary: these devices do not work to anything like the levels claimed. The original article follows.

Early in July 2019, I saw the Chillmax Air advertised on TV in one of those shouty ads. That 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.

I’m a chemist, and I know that in order to cool a large space effectively you’re going to need something with a big fan and a special refrigerant. In practical terms, that means a fairly bulky device with a motor-driven compressor, a closed radiator for the refrigerant to pass through, a fan to suck air in and blow it across the radiator, and a wide exhaust pipe through the wall or window to get rid of the ‘removed heat’, and – in some cases – a drain for the condensed water which results from cooling the air. A typical proper air conditioner for a small or medium-sized room will be about the size of bedside cabinet. The Chillmax Air is not much bigger than six CD cases glued into a cube.

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If you’ve ever used a normal desk fan you will know that you only feel cooler if you’re sweating a bit. That’s because the fan evaporates your sweat as it pushes air over it, and that evaporation is accompanied by a cooling effect – it’s called ‘evaporative cooling’. If you’re not sweating, you don’t feel the effect. Conversely, if the surrounding air is very humid, then no matter how powerful your fan is, you will feel little or no cooling because sweat can only evaporate if the air has capacity to hold additional moisture (I’ll explain that a bit more later, because it’s what determines whether the Chillmax is any good).

Many liquids exhibit the evaporative cooling effect. In the case of diethyl ether, for example (that’s the stuff they used to use as an anaesthetic), if you force it to evaporate very quickly you can even freeze water (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 the fumes gave me a massive headache), it doesn’t have much practical application these days. Early refrigerators used it, which was spectacularly dangerous.

The Chillmax Air uses the evaporative cooling effect of water, and this is much less than with ether – similar to sweat, in fact. 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. If you believed the ads, 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 was.

When I first 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 – but note that that it’s only a 5″ computer fan, so it can’t beat a proper desk fan for air flow. The air did seem a little cooler compared with what my desk fan was blowing at me, but it also felt ‘softer’ – that’s very important, and I’ll explain 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 powered up the Chillmax and moved the logger in front of it for the same period of time. This is what it recorded (the red line is where I moved it).Chillmax - temperature log in hot and sticky conditions

The ambient temperature where I ran the test was about 29ºC (this was just before the 2019 heatwave kicked in properly). The Chillmax brought this down by about 4ºC.

So, the Chillmax definitely cools the air that passes through it. Let’s work on the assumption that it would be able to get the same 4ºC drop no matter what the ambient temperature was. If your room is 38ºC, pulling it down to 34ºC still means it’s bloody hot. And also note that the Chillmax is physically quite small, so the cooling is very localised – it won’t cool an entire room down, and you have to have it less than a metre from your face to feel anything.

Now, some people might be thinking that a 4ºC is better than nothing at all. And they’d be right if it was just a matter of temperature. But there’s more to it than that. I mentioned that the exhaust from the Chillmax felt ‘softer’. I knew what it was, but my data logger shows it in numbers.

These are the data for relative humidity recorded at the same time as the temperature measurement, above (the red line is where I moved the logger). The humidity went up dramatically – a jump of about 30%RH.Chillmax - RH log in hot and sticky conditions

As I’ve already explained, the Chillmax works by evaporating water on fibrous panels by forcing air across them. That water has got to go somewhere, and in this case it comes out with the cooled air as water vapour. In the right light, you can actually see it – it’s essentially fog, so the cooled air is also moistened. And just like when it’s foggy outside, and everywhere gets damp, this water vapour can condense on cooler surfaces. My data logger collected some and began to drip during the test, and I have since discovered that it also condenses on the front grille and can drip periodically, so you’d need to be careful what you had underneath it if you placed it on a shelf. The fan is quite powerful enough to project the drips forward slightly when they drop.

The ambient humidity in the room where I did the test was about 44%RH. The Chillmax sent that up to over 70%RH. It is this elevation of the humidity of the cooled air which really brings into question whether the Chillmax is worth the investment.

You’re probably aware that you can have a hot summer day in the high 20s where it is pleasant and comfortable, but a cooler and overcast day might be horribly sticky – or muggy. That’s because of the humidity, or water vapour in the air.

The amount of water vapour that air can hold varies with the temperature. Cold air can’t hold much, but warmer air can. At any temperature, once you reach the maximum amount possible, any extra vapour condenses out as liquid water – misted up windows, dampness, even drips and pools of moisture on window sills or under lamp posts. In winter, the condensation point is reached very easily, which is why you get your windows all steamed up and everywhere is often damp, but in hotter weather it is more appropriate to think ‘sauna’ (which is why it gets ‘muggy’). This air moisture is what we call ‘humidity’.

The term ‘humidity’ usually refers to the absolute humidity, which is amount of water in the air. However, the figure most people are referring to is the relative humidity. This is the amount of moisture in the air expressed as a percentage of the maximum amount it could hold at that temperature, hence the units %RH. It’s a complicated subject, but the important factor for us here is that when it is warm or hot, higher absolute humidity is uncomfortable because the amount of moisture in the air relative to the maximum possible is higher. Indeed, you may have seen weather forecasts where they give the actual temperature and the ‘feels like’ equivalent – that’s a reference to the ‘Heat Index’, which takes into account the effect of the %RH. Here’s a graphical chart for that.Heat Index - graphical representation

As an example, if the air temperature is 30ºC and 50%RH, it will feel like 31ºC, but if the humidity goes up to 80%RH, then it will feel like 38ºC – even though the thermometer still tells you it’s 30ºC.

Another example. If the air temperature is 35ºC, at 50%RH it will feel like 41ºC, but send the humidity up to 80%RH and it’ll feel like 57ºC – even though the thermometer still reads 35ºC.

The calculation for this is complex (you should see how long my Excel formula for it is). It is non-linear, and the increase in ‘feels like’ is greater at higher temperatures. It also contains an element of opinion/perception, which is why there’s no point using numbers above about 60ºC. But the ‘Heat Index’ is what forecasters use. Incidentally, the official health designations for the colours are: yellow – caution; amber – extreme caution; orange – danger; and red – extreme danger. Vulnerable people need to take these into consideration before going out in hot weather.

However, this is where the problems come in for the Chillmax and similar devices. If it’s 35ºC and 40%RH, it’ll feel like 37ºC. Cool the air to 31ºC but send the humidity up to 80%RH, and it’ll feel like 41ºC. So it’s actually hotter in terms of comfort. Do the same comparison when the surrounding temperature is 38ºC, and the ‘feels like’ goes from 43ºC to over 50ºC!

At lower temperatures the Chillmax will produce a slight net cooling effect. But if the air temperature is above about 30ºC (and 50%RH) – which isn’t excessively hot or humid to start with, though it is around the point where you would start thinking about cooling things down – it’ll actually make you feel warmer. And if it is already humid outside, you’ll feel hotter still.

Proper air conditioners remove water from the air they cool. This removal of moisture is why the air from proper air conditioners feels crisp, as opposed to the ‘softness’ of moist air. 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 officially replace the fibre inserts in the radiator, 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 likely on the lowest of the three fan speeds, since on top speed it runs out in less than three hours.  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 isn’t just the temperature that needs to come down.

Now. All of the above is an absolutely independent analysis. It came about simply from buying a Chillmax Air, testing it, then understanding what it was doing. None of the conclusions I arrived at were influenced by any other sources – I didn’t look it up first, nor have I had any inclination to do so since I first wrote the article. My measurements were factual, and my explanation was scientific. However, as of 2022 I decided to do just that and look up reviews of evaporative coolers. You might want to look at a few of these links, because I was right.

Do Swamp Coolers Actually Work? | Wirecutter (nytimes.com)

Evaporative Coolers Vs. Portable AC Units: What is right for you? – NewAir

Are evaporative coolers as good as air conditioners? | ProductReview.com.au

10 Things to Know Before Buying Portable Evaporative Cooler (vankool.com)

There are many, many more. And in every case, the relationship with humidity is the key. If it is already humid, evaporative coolers do not work and actually make things worse.

At the time of this most recent edit, it is 20 minutes past midnight on 19 July 2022 and the official Met Office temperature in Nottingham (where I am) is between 28ºC  and 29ºC (it was just over 37ºC  earlier on 18 July). Humidity is 35%RH, but it is up to 60%RH less than 40 miles away at the next Met Office station. In Nottingham, humidity peaked at 60%RH on 18 July, even if it dropped to under 30%RH at times. And that was outdoors – indoors you can add 30-40%RH without blinking.

Evaporative coolers are a big risk with the humidity we experience in the UK. And especially indoors.

Does it really work?

It does cool the air by a few degrees, so in that sense it works. However, it also sends the humidity up, and in most cases that actually makes you feel hotter and more uncomfortable. In that sense, it doesn’t work.

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. Only this evaporation results in the cooling effect observed.

Will it cool more if I put the filter in the freezer?

It might – while you’re blowing air over ice. But once they defrost, which will happen in a few minutes in the temperatures you’ll likely be experiencing, then no. You’ll also have more condensate to deal with from the melted ice pouring out of the front grille.

You may see reviews on Amazon claiming that freezing the filters (or using ice cubes in the water tank) does give cooler air. Trust me – apart from what I just said about blowing air over ice, it doesn’t. Science is involved, and evaporative cooling doesn’t work like that.

Can I use it to cool my PC?

Someone found this article on the search term “jml chillmax air for pc cooling”. No. Blowing damp air into your PC would be dangerous, potentially expensive, and would only gain you 4ºC at best.

Can you get larger versions?

Until August 2021, the answer in relation to the ChillMax was no. However, I saw an advert (as shouty as usual) for the InstaChill tonight. Unlike the ChillMax, which is the size of a small table top radio, the InstaChill is the size of a bedside cabinet. And you can certainly get larger evaporative coolers from other manufacturers. The working principle is identical, except 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 (and the more moisture being pumped out to increase the humidity). 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, so the cooling effectiveness will decrease as the humidity rises unless you vent it somehow. Be careful if you read any of the reviews on these things – people may have noticed cooling in already cooler conditions, but trust me – if it’s very warm and humid, you will not notice any effect.

People say it works

Be careful when you read those one-line reviews. If you test it when it’s only 20ºC outside – as many of these people have – then yes, it blows noticeably cooler air at you. But science is involved, and at temperatures above about 28-30ºC you’ll actually feel hotter. The fact that it increases humidity is the key factor. Remember that the reason you even found this article was probably because it’s over 30ºC outside – the more above that it is, then the more hits I get.

So, does the Chillmax/InstaChill work?

They cool the inlet air by several degrees. But they send the humidity of that air up considerably, and this cancels out the benefits of the cooling effect when it is very hot. The ‘Heat Index’ is the key detail, as explained above. In the case of the InstaChill, it will add a lot more humidity than the ChillMax, and as I have explained and demonstrated, the ChillMax is bad enough when it comes to increasing the ‘feels like’ temperature.

Only the air being directed at you is cooler. Once that slightly cooler air has passed through warmer air, it’ll be close to ambient again. The device cannot cool down a room. It’s far too small for that.

Humidity can carry much further, though, and it hangs around unless it condenses out somewhere. So in a small room, you could easily increase the ‘ambient’ RH without any cooling at all, and that will make it feel even hotter. If it is already hot, the amount of water vapour the air can hold before reaching 100% RH will be substantial. The increased humidity of the outlet air does produce localised condensation, so you have to be careful to keep these devices away from electrical sockets where they might drip on them, and there is also the risk of dampness in your home and the problems that it can cause. The devices also contain a significant volume of water when full, so you don’t want to knock them over.

Should I buy one?

My advice is to buy a proper air conditioner (A/C). If anything costs under £200 it is not a proper A/C. However, it is possible some people might find the minor cooling effect and increased humidity of the Chillmax/InstaChill (and similar devices) beneficial, so the choice is yours. But for real cooling and dehumidification when it is hot, it has to be a proper A/C.

Driving Instructor Banking

UK Banks montageSomeone found the blog on the term ‘what bank should I use as an instructor’?

The answer is simple: It doesn’t matter who you bank with.

All you need to be able to do is pay money in and get it out when you need it. As a sole trader, you really don’t need a business account (which usually has a monthly fee of between £5-£10, and extra fees for depositing cheques), but if that’s what you want then it’s up to you. Some banks will try to insist you have a business account if you bank with them, but my advice would be to find another bank unless you’re happy to be charged for something most will provide to instructors and sole traders for free,

Personally, I bank with Halifax, and all my money goes into and comes out of the same personal account. The vast majority of my driving instructor income goes in either via my PayPal Here card reader and PayPal account, or as cash at a Post Office (I avoid the Halifax branch like the plague, due to inefficiency and idiot customers). Slightly less often, it goes in via bank transfer or via a direct PayPal payment. I never accept cheques as lesson payments now, and I only ever get a cheque if I’m being paid by a corporate source (another bank, insurance companies, and so on) – or the old lady who lives next door whose shopping I do since the pandemic.

This article was originally written quite while ago, and at the time cheques were the only source of payment problems I ever had. I can’t remember any ‘bouncing’ (but they could have) – the main issue was how they were filled in. Any incorrect information or smudging and they’d get rejected. It didn’t happen often – but it happened, and it was exacerbated by the fact that the bank took weeks or months before sending them back, which affected cashflow even more, and created administrative issues in getting it sorted. Cheques have no immediate value until you have banked them, and although these days the banking apps allow you to scan them and pay them in without going to a branch, it still involves hassle and at least three days before the money is yours.

About 20% of my turnover is still cash, and I can easily accrue up to £1,000 in my wallet over a month or so, so I still have to physically pay money in occasionally. Fortunately, as I mentioned, at the Post Office.

I have to be honest and say that Halifax is utterly crap as far as its branches are concerned. To start with, they don’t have many left, and those they do are located in places where you find a lot of idiots (e.g. West Bridgford and Arnold shopping precincts). First of all, you have to find somewhere to park, and in West Bridgford that means having to pay (and the traffic wardens hunt in packs, ready to nab you if your ticket has a crease in it or is placed crookedly on your dashboard). In Arnold, if you’re lucky you can find a free roadside spot, but if not then you have to pay there, too. West Bridgford town centre during the day is like a geriatric village of the damned, and even if the car park has spaces, there’s a good chance you won’t be able to get to them because of elderly and disabled drivers stopping next to the fully-occupied disabled bays waiting for someone to move (or trying to avoid buying a ticket while they wait for their partner to come back from shopping). In the afternoon, mummies in Chelsea tractors do the same as they pick their kids up in the car park, or wait for a space near the shops instead of driving round the other side where there’s lots of empty places.

If you do manage to park and get into the Halifax branch, the size of the queue at the till (and the complexity of the transaction each member of it is trying to complete) is inversely proportional to how big a hurry you are in. There’ll be women with pushchairs whose kids are running around screaming, people with bags of coins, those making withdrawals as if they’ve never heard of a cashpoint, and several elderly people with bank books who behave as though they’ve never done this before when they get to the till (and who then go straight to the cashpoint to make sure the money has gone in, and often to take some out again less than five minutes after putting it in).

The number of cashiers on duty is not proportional to anything. They only ever have one unless the number in the queue is approaching three digits. Then they still have one. But sometimes two, although that isn’t proportional to anything either.

On the rare occasions I have used the cashier, the simple act of paying cash into your account takes five minutes. This, too, isn’t proportional to anything. It just takes five minutes – possibly a bit longer if you have a lot of cash and what they count isn’t the same as what you counted. The vast majority of that five minutes is taken up by their printing device, which takes nearly that long to chisel your receipt on to small clay tablet.

Of course, there is the Fast Deposit machine. This miracle of technology does exactly the same thing as the cashier, and it even takes exactly as long as the cashier. All without involving the cashier at all. Brilliant. Except that Halifax branch staff have been encouraging as many people as possible to use it to try and keep the queue for the till inside the building. Many of those thus encouraged seem incapable of understanding that those little metal things called ‘staples’ and ‘paper clips’ are not supposed to go into the machine, so it is frequently not working. And even when it is, if there’s more than one person waiting to use it, you’re no better off than standing in line waiting for the till. It was that which led to my last ever visit late last year.

I went in, and there was the usual queue for the single cashier. There was only one person at the Fast Deposit gizmo, but it quickly became clear he was having a financial discussion of some sort on his phone. He had several cards and a thick wad of cash. He wasn’t actually using the machine, but he was going to, and the supernumerary cards suggested the money wasn’t all going into the same account. So he was effectively three or more people – all of them f***ing stupid – all by himself. I stormed out – I swore audibly – and when I got home began looking for another bank.

If I’d have calmed down a bit, I would have realised that it was going to be the same whoever I banked with if I needed to visit a branch. Years ago, while I was with HSBC, I went into the now closed branch in Keyworth, only to get stuck behind a local farmer who was paying in hundreds of pounds in coins! And whenever I used to go in NatWest or Barclays, the cashier getting up and disappearing in order to deal with whatever the idiot at the front of the queue was trying to do would make my blood boil. But it was while I was angrily looking for a new bank that I discovered I was now able to pay into my Halifax account at the Post Office.

At first glance, this might not seem the panacea it has turned out to be. That’s because the people who frequent Post Offices are a hundred times more stupid than those at the bank branches. I recently got stuck behind someone who was apparently an eBay seller, and they had at least 30 small packages, each of which had to be individually bagged and labelled for some unfathomable reason (when I sell on eBay, I bag and label at home and only use the Post Office as a drop off if they won’t fit in a post box). Or in the village branches, they are gathering places for the elderly to have a chat, often with the elderly Postmaster (who also runs the tiny general store it is attached to), and if you walk in as an unfamiliar face, that chat takes absolute precedence over whatever it is you want to do. But the major advantage is that there are a lot of them, parking is usually a doddle, and there is always one either very close to home, or along the route as you are driving between lessons. And paying cash or cheques in at a Post Office is quick – I am usually in and out in less than two minutes.

I don’t know how long I’ve been missing out on this, because I looked into a it a few years ago for precisely the same reasons as I did this time and the service was only provided to the big banks (which didn’t include Halifax). But it seems to be almost universal now.

Why don’t you accept cheques?

There is no need. Anyone who uses cheques to pay for stuff will have a cheque guarantee card, and these days those things are chip & pin cards. Since I can take card payments, a cheque is a pointless complication. The only possible benefit to a pupil who wanted to do it would be to defer payment by however long it takes for me to bank it, plus however long it takes my bank and theirs to process it. If I didn’t pay it in immediately, there’s an increased chance that they will be skint again by the time I did. For me, there is no benefit at all, since it forces me to go to the bank if I want the money, and that is just wasted time and all of the hassle I have already outlined.

Other instructors take cheques

That’s because they can’t take card payments, meaning that unless they get paid in cash (including driving the pupil to a cashpoint to obtain it), or do it by bank/PayPal transfer, a cheque is the only alternative. Getting pupils to pay by bank or PayPal transfer is a hassle in itself, as is driving to cash machines a lot of the time (especially when they’re out of order or there’s traffic). When mine do it by transfer, I often have to keep chasing them because they ‘forget’. I’ve got better things to do,

What if people can only pay you by cheque?

I would imagine the number of people in the entire country who are truly in that position could be counted on the fingers of one hand. If they can write cheques, they will need a cheque guarantee card, and that doubles as a chip & pin – which I can accept directly. If the bank won’t give them one, there is probably a damned good reason for it, and I have no desire whatsoever to find out why by accepting non-guaranteed cheques from them.

As I said, I can handle cheques. I choose not to as a routine method of payment because there is no good reason for them these days as a way of paying for driving lessons. It has not been an issue, and if it ever became one then I would consider each case on its merits. It isn’t one of my accepted methods, that’s all.

Why bother with a card machine?

It’s quick, and I get paid immediately. There’s no chasing, and no risk of loss to me. Since I started using such a device nearly I have taken several hundreds of thousands of pounds with it (and yes, it all gets declared when I do my taxes, as does any cash I take). It also means I have good records for tax purposes. Frankly, I wish everyone would pay by card, but it isn’t uncommon for people to have their own reasons for insisting on cash – even if it involves as much as £700 for a complete course!

Isn’t it illegal to use a personal account for business transactions?

No. You only need a business account if you are a limited company. Sole traders – such as ADIs – are operating perfectly legally if they use a personal account. The only reason for choosing a business account would be to keep things simple for when you do your tax return – but it isn’t that hard in the first place for instructors.

Note also that some banks don’t like it if you use a personal account this way and will expect you to open a business account – and close your personal one if you don’t. That’s between you and the bank’s policies, and not a legal issue.

HMRC will audit you if you use a personal account

Well, I’ve been doing this for long time and I have never been audited. I wouldn’t be worried if I was, because my accounts are clear (and true). HMRC are far more interested in you if your numbers don’t add up properly – if your profit ratio isn’t what it should be, or if your declared turnover doesn’t ring true, for example.

What I have noticed is that at least some ADIs who make this claim will also have boasted at some point how little tax they pay, and if they’re saying it because they’ve been audited, well, there’s the real reason right there. In my case, I simply pay what is required after all my overheads have been subtracted from all my turnover. If you’re honest, and doing this full time, there’s no escaping the fact that you need to pay taxes – and the annual figure when you complete your Self Assessment isn’t going to be very attractive if you haven’t been planning for it throughout the year.

Too many people start in this job, end up working 30 hour weeks, but don’t put their taxes aside as they go along. Then, at the end of the year, they need to find around £1,000 to pay their bill – usually, just after Christmas to make matters worse. Fair enough, you pay half in January, and the other half in July, but it’s still a lot.

COVID Complacency And Stupidity

covid_bb

I’ve not written about Covid in a while, though I have had to deal with many situations involving it in working as an ADI.

I’ve explained previously, but I am carer to my two elderly parents, both of whom have age-related health issues which put them in the ‘extremely vulnerable’ group as far as Covid is concerned. I make it absolutely clear to all my pupils that they must tell me if they test positive, and I explain clearly why. And all of them have done so.

Two weeks ago, a pupil who is pregnant got it. So we cancelled for ten days. Although it may not be related (though evidence suggests it could be), she is now suffering from pre-eclampsia and has been in and out of hospital with high blood pressure and the other symptoms. I hope it works out for her and her baby.

But that is an aside. I got a text from a pupil this morning cancelling her lesson tomorrow because she has just tested positive for Covid. I also got a message from another pupil – who is a work colleague of/referral from the first – cancelling her next lesson on Saturday (she also had one Sunday and Monday, as her test is coming up).

I casually texted back that her friend had tested positive, and would she do a LFT before our Sunday lesson, and she came back with ‘yes, I know. She caught it off me’!

The penny didn’t immediately drop, since she told me she was back at work tomorrow (Thursday). But once it did drop, I asked her when she tested positive herself. Saturday – less than five days ago! And she has symptoms – she’s all croaky – and yet her employer (she’s a teaching assistant) wants her back tomorrow.

The NHS says the following:

If you have COVID-19, you can pass on the virus to other people for up to 10 days from when your infection starts…

You should:

  • try to stay at home and avoid contact with other people for 5 days
  • avoiding meeting people at higher risk from COVID-19 for 10 days, especially if their immune system means they’re at higher risk of serious illness from COVID-19, even if they’ve had a COVID-19 vaccine

This starts from the day after you did the test.

I spoke with her this evening and she fully accepts the need to suspend lessons for the 10-day quarantine period.

But I cannot believe her employer wants her back while she is still unwell.