How did the aircon cope?

Well, it coped quite well.

The red line is the temperature at my desk, which I was aiming for 22C. In practice the floor ends up around 20C.

The interesting bit is the blip around 13:00 where it got colder. It seems that the aircon is not doing what I expect. In order to control the temperature at my desk rather than at the wall controller or the air inlet in the loft, I tell the aircon a target temperature. When too cold I tell it to to cool to 5C higher than the wall controller. When too hot I tell it to cool to 5C lower than the wall controller. This works to turn the compressor off or on. But as the inlet (pink line) got hotter we got to a point where telling it to cool to 5C higher was not turning the compressor off. This means that it is clearly using the inlet as a reference, or possibly inlet and controller average. The inlet is interesting as (being ducted) the air leaves my room, via some ducting in to the aircon in the loft, and the loft temperature was up to 40C, meaning the inlet temp sensor was way hotter than the air actually leaving my office.

This is rather annoying as there is an explicit field setting to tell it what to use as a reference and that is set to the wall mounted controller. The fix was to change my code to allow me to expect the reference to be the inlet temperature or the controller or average of the two. As you can see, that fixed it.

However, from around 14:30 it was not going below 22C. The thicker line is my code making the fan speed higher in an effort to get it to go down to 22C. The compressor was on and the coolant was cool. But it was struggling. My office got up to a roasting hot 22.4C :-)

All this was on one of the hottest days of the year. So, yes, I think it is working well :-)

A bit more on air-con

I have been tweaking the air-con even more.

The control I have, basically, is to set the target temperature. I can set higher than now, and lower than now, and so make it turn on or off. But sensibly the air-con has controls. It does not run the compressor exactly to match what I say, it turns on for a minimum time, and there are also sorts of laggy effects for the temperature to react. Once compressor was on it stays cool a while and then fan blows cool for a while.

But it is getting silly.

For the last hour or so, even more so. This is not like ±0.1℃, it is more like ±0.05℃.

It is really good. But I was thinking, is this just that it is a cold day in Wales and the temperature happens to be settling where I want? At 22℃?

Well no, it is not that, looking at the power usage I see that it is turning on and off the compressor to work the temperature.

What I did was make it predict on a trend the next 2 minutes and turn on/off (set high/low target) based on that. And it was surprisingly good. This is the power usage showing it is fine tuning it to manage that. It is controlling the temperature to well within ±0.1℃ with no problem.

Wow.

P.S. Just to clarify (as someone asked), this is not switching between heating and cooling (which would use more power), this is turning cooling on and off. It will switch to heating, but only after quite a while of temperature not coming back within range when off - and that can happen on some days in spring/autumn, but usually only once (each way) in the day. It also does automatic fan control.

New air-con, part 6

Well, well, well... I am impressed with 4 Seasons. They have only gone and sorted it.

This is the huge difference between this install and the previous Mitsubishi install from a different company. The customer service to get to the bottom of the problem and fix things.

Firstly, they did discuss this "anti-freeze" mode with Daikin, and whilst we all agreed that turning the fan down was silly, their point, which is very valid, is that it should not be happening at all. The refrigerant should not be getting so cold in the first place - this is a fault condition. That is what needs fixing.

Naturally I leapt to the conclusion that the issue was air-flow. But I was wrong. It seems the advice from Daikin at this point was right - they said to check the refrigerant. Well, pressures had been checked several times. But they suggested there was too little refrigerant. Indeed they suggested (counter intuitively) that we would see these lower temperatures if there was not enough refrigerant. That seems crazy, obviously.

Well, the installer, and I, were rather baffled, but the only thing that basically makes sense is that the system is (over) compensating for the lack of refrigerant, and that is how it ends up colder. And, of course, at the same time, it is unable to carry the heat away properly, so does not work as well.

The symptoms were pretty simple, when cooling, the refrigerant quickly goes down to as low as -10C, which it manages for a few minutes, and then the anti-freeze mode kicks in, and everything stops for 10 minutes, and overall things are not working well.

Now, the refrigerant is settling around 5C with no problem, and cool air is coming out, and the room is quickly cooling. It is not going negative at all, not even getting below 4C. It varies, and I have seen 5C to 8C, but that is "sane".

So what did we fix?

The fix was to completely drain down the system and refill it - simple as that. The big clue was that only 0.9kg of R32 came out. It should have had around 2.5kg. So he emptied, vac'd, and refilled. What I had not appreciated is that these systems come pre-filled for installation, so it seems that somehow it must have come without the right amount - some must have leaked in transit (not good). But the only real test he can do is pressures, and they were fine, so no clue that there was not the required amount of R32.

I'll add some graphs once we have a couple of days running to confirm. But I am sat here on a warm sunny day in a nice cool office. To say that I am over the moon is putting it mildly.

Side effects

A small side effect is that my Daikin wifi modules have way more monitoring and reporting and graphing now. I did loads of work to try and find what was actually happening, turning in to a seriously useful tool.

Next job is the new controller to work with it for when people want manual control but doing a better job than the normal Daikin controller.

Another small side effect is that my previous very tight temp control is now a little less tight as the effect of cooling (or heating) is much more and continues longer, so some level of predictive processing may be needed to manage tighter temp control. Should be pretty easy.

New air-con, part 1

As you will know from my previous posts, having moved to Wales (over a year ago now), I wanted air-con installed. I had this in Bracknell and am very used to it. Also, last year, it got stupidly hot. The good news is I am also installing solar panels and battery which should cover the power usage of air-con in the summer, and a lot more. More on that later in the month.

Last year we got air-con, and after months of faffing, it was finally taken out. It was simply not good enough in a lot of ways. I promised a blog on this, and you will have one, next week, when the new install is finished. But I can say it is very very promising!

However, today, I am blogging on the Daikin WiFi adapters.

Oh my, this was hard work!

The ducted units appear as WiFi access points, and there is a label and even removable sticker with the SSID and the passphrase. It even has a QR code, yay!

The QR code is quite dense, but guess what - it is not a WiFi connection code which your phone would understand and connected to the WiFi, no, it is just the "KEY" (passphrase) which the phone naturally thinks is a phone number. Why do that?

Connecting to the WiFi AP gets an IP, good, and there is a web page on the device IP, good. But it is just a set of free s/w licence details. No actual web interface. Just a simple page to allow setting the SSID and passphrase as a client - that's all it would need in an ideal world, but no. They could even make DNS such that it appears as a "splash" page when you connect on most phones. Not actually that hard. Shame.

The good news is that there is an app. And the instructions say to use the app. They have a QR code, but it just goes to apps.daikineurope.com which helpful explains you need the "Daikin Residential Controller" app. No helpful link to get it - no, that would be too simple. There is no "Daikin Residential Controller" app! There is a "Daikin Online Controller". There is an app called "ONECTA". There are a lot of third party apps too.

The Daikin Online Controller app does not work, but it does have step by step instructions on how to get things to connect, which I tried. They don't work. Lots of on-line help has the same, even videos. Things like "Hold MODE for 3 seconds" on the wifi module on the device, to make it show "AP" light. Well these units were clearly being APs, but the AP light was off, and pressing MODE did nothing. Very annoying.

I also have a wall mount unit, and the instructions are holding a button on the remote for 7 seconds, and then selecting a number. Again, that just does not work. Now, I know that worked in my old house with Daikin wall mount units. Again, very annoying.

It turns out "ONECTA" is the app you need and the old app does not work at all. Arrrg.

But then it insists you need an on-line account on some cloud services - not amused, but I was hopeful that once on the WiFi here I can do stuff directly and just kill off the app later. So went ahead.

If connected to the AP from the air-con the app "sees" it right away, great. You select, and it connects to the device, and then to the cloud service, which obviously does not work as the phone is not on the Internet - it is connected to the device. If you swap WiFi a bit you can progress more, but ultimately you cannot actually get it working.

I found loads of on-line help, all of which appears to be based around the older app, which no longer works.

Eventually I found you can manually add a device on the app, and if you manage to pick the right options you eventually get to ping pong talking to device and your normal WiFi and it will put the device on the wifi. Finally. Hard work or what?!

Worryingly the app wants to know where I am so it can check local weather - why? The temperature I want my room does not depend on local weather. Worrying.

The app also insists I change to indoor control for temperature and not the wall mount controllers I have. Well I want to use the wall mount controllers for temperature, so really not sure about that!

Anyway, I have ducted units on line now, but what of the wall mount air-con unit? It is not appearing as an AP even. Well, thankfully the manual adding instructions on the ONECTA app does explain - you take the cover off, open a flap, pull out a wifi controller module (looks just like the ones on the ducted units). But on this one you *DO* have to press MODE for 3 seconds and the AP light comes on. WTF? I now have that unit on-line too.

The Daikin units used to have some simple http based APIs that allow basic control. Loads of details all over the internet. Guess what? They don't work. So this will probably mean some reverse engineering.

That's enough for today.

P.S. the wall mount controls for the ducted units have bluetooth and an app that just works quite nicely with them without any hassle. Also, the previous air-con attempt had neither WiFi nor Bluetooth - so whilst this may seem some hassle, it is already a massive improvement!

P.P.S. (Thanks Matt) WHY OH WHY do they still broadcast the set up SSID even when a client?!

Part 2

Where are we with the air-con?

I had aircon in my old house - standard split system with indoor units on the wall. It worked well. Summer or winter, extreme hot or cold, I was able to ensure bedroom and office stayed well controlled and comfortable. Not once could it not cope.

For the new house I put some money aside to invest in an even more serious aircon, ducted, with a lossnay and for fresh air as well. We are directly on the A40 with no vents in windows, so needed. It is far from cheap (A lot of houses in wales are probably cheaper than this installation!). I was keen, and happy, to pay "top dollar" for a "proper" system. This is my retirement, my comfort, I deserve this!

As I have said on twitter, that it is Major Cooling & Heating that are doing this. They were recommended, and have been in business some time.

They are nice, and friendly, and do seem reasonably competent on the face of it. So we ordered the system and it is installed. It took some time. It involved a lot of work we had to do with help from my son-in-law/sparky.

But it is not right, sorry. I do feel a tad sorry for them - as it looks like they took all the room sizes, and so on, and contacted their suppliers that recommended a Mitsubishi system with Lossnay and GUG. It was installed, then the issues started.

There are two big issues.

1. It cannot read the room temperature from the controller. This is the controller that comes with it, which they says is not even a "standard spare part" as it is specially for the GUG, yet it has a thermistor in it, and has a setting to use the controller temperature, which it accepts. This fooled us as clearly it was not using the controller, freezer spray made that really easy to demonstrate!

2. It does not seem to be powerful enough.

The first point is pretty much a show stopper. We have two rooms on each of two systems, and may want to run one or the other or both. The fact we want to cool the "secondary" room was important as my wife and her sister when using the guest room, have very different ideas on a "comfortable temperature"! We do accept that if we are running both rooms at once, then they are not separately controllable - we know that.  That was not actually a problem for us. For the "one or the other" we actually put motorised vents to each room and switched the controllers in each room so only one was connected. Simple, or so we thought. But apparently, even though it has at thermistor and a setting, it can only read the "return air flow", which only comes from one room! Not impossible to fix with more vents and more motorised vents in the pipes for the return air flow, but for one room this meant removing wardrobes, and plaster board and trunking a vent in the wall and lots of work (which we paid for separately) and may now need doing for the "return air" if we do that. Not good. Not impossible to fix.

Even so, we now know that this also means much more careful placement of the vents in the rooms else the feed air just runs along the ceiling to the return vent and thinks all is well and the room is warm. This meant changes to vents, and lots of testing. Getting the airflow matters way more if the temperature sensor is not the controller, put where we want it.

The second point is, frankly, a bigger concern. It got to over 28℃ in my office last summer. So a system that can cool even that one room to 21℃ is needed. I was clear I wanted an "over spec'd" system if necessary to do that. But as it is not the height of summer I have no way to test that. All I can test is heating. Well the system says it can do 28℃ heating. So let's try!

The answer is a solid "nope", by several degrees. One system managed one room (not the two rooms and en-suites it should do, just the one) up to 25℃ after some hours. The other much the same 24℃. Yes, it works for 20℃ and so is actually fine for now, but if it cannot cope with heating many degrees now, how will it cope with cooling many degrees, as many as 7℃, in summer?

At the end of the day this gives me zero confidence the system has enough "oomph" to cool my office in the summer at all.

Can I help? Well, I am. I have invested in more test equipment, calibrated sensors, etc. I have tried everything even moving and changing vents. We had the vents all changed to larger size at the start when it was apparent it would not cope. I am doing everything I can to make this work if at all possible. But no luck.

I am now putting in several sensors in one room at 0.5m height intervals to see if the air circulation and heat distribution is somehow a factor. But even so, the basics of "not enough oomph" is pretty clear.

So next step is down to Major Cooling & Heating to see if they have an answer, changes to the system, an alternative system, or a refund. We will see how good they are.

Mitsubishi Lossnay+GUG aircon (not actually working)

We have a bit of a mystery here - the brand new, expensive, ducted air-con in the house does not work!

So what does not work exactly?

Not actually able to cool a room!

The biggest issue is it cannot cool a room - not even close. (It can't heat one much either)

This is a temperature plot for my study, 3m x 3m, you don't get a lot smaller than that in terms of a room to air-con. A=Portable unit on, B=Portable unit off, C=Start two hour cool only full fan test.

The test was with the other room vent closed so the unit was only cooling one room, in to a closed empty room, no heating on anywhere in the house, and outside temp of 19C. Not a challenge for any air-con really, and as you can see, the cheap portable unit managed with no problem (even with the door open most of the day). And yes, the fan speed control does work, and was on full.

I expected at point C the room to cool at least as fast as the cheap portable unit. What happened is it just about managed 0.8C in two hours! It was blowing cold air (measured at 9C) but not as lot...

The fix - well, the unit only has a 100mm vent in to the room. This seems small I must admit, and at full fan like this it is noisy. So they are changing to a 150mm vents today...

Did it work? In short, no. The bigger vents are quieter, which is nice, but the same tests showed maybe 1.5C drop and bottoming out just below 21C after more than an hour. Compare these big 3.5kW systems to a much cheaper 1.5kW portable unit which is able to drop my study (and hall way as door was open) from 23C to 18C in 15 minutes. With the door open the new air-con cannot cool my room at all!

This is now waiting on Mitsubishi to explain and fix. I won't say who the installers yet as they have been pretty good. Let's give them the chance to get Mitsubishi to fix it all.

But how is this even possible?

The issue for me here is that they sell this system, even with the smaller 2x 100mm outflow vents. So forgetting, for a moment, whether the suppliers got it wrong for the rooms we are trying to cool (two rooms each unit, one of which is much bigger than this 3m x 3m study), we have the issue that this whole unit running at full cooling and full fan cannot cool a 3m x 3m room.

So what the hell is the this unit for - what size room are they expecting it to be used with, ever?

The change to 150mm vents actually meant them cutting out the larger holes as the cowl as it is only supplied with the 100mm outlets.

This leads me to think something else is wrong, but we have no idea what. How could this ever work anywhere?

Cannot set temperature!

The controller has options - either "return air" temperature measured at the lossnay unit, or the room temperature at the controller. The controller has a sensor in it. Given that we have two rooms per unit, we are using the temperature at the controller (which is not in the room with the return in it). This is all as per the manual.

Only it does not work! Cooling the room down to 19C (using the portable unit, obviously), it showed 24C. Indeed, it even went up from 23C while we did this. Using freezer spray actually on its sensor does nothing, still 24C. No clue where it is measuring but it is not in the room - we even tried putting hot air in the room that has the return air flow but that did not make it go up at all.

The fix: Well, again, waiting on Mitsubishi.

Watch this space.

New Mitsubishi Ducted Air-con with Lossnay (bad user interface)

As some of you will know, I have moved to sunny Wales. My new home did not have air-con so I am finally having that installed. I have gone for a ducted system this time (yes, more expensive) as it allows simple vents in the ceiling rather than a large indoor unit in the rooms, and it should be quieter. However, the main reason is that we now live on a main road, so cannot really open windows to any of the bedrooms - the ducted system I have gone for has a "lossnay" which provides fresh air as well, and saves us having to open windows. More on the actual aircon later, this post is just about the quite unbelievably bad user interface.

For a start this is an "industrial" air-con, which sadly means it is a simple wired controller and not WiFi, or anything useful like that - do not be surprised to find a "reverse engineering Mitsubishi air-con controllers" in a future blog post :-)

The air-con is three parts, an outdoor unit, and indoor unit (GUG) which does the cooling/heating, and a lossnay which does the fresh air (filtering and heat exchange). This is in the loft...

The lossnay is on the left and the GUG is on the right. To be clear, the GUG is designed to work with a lossnay, it cannot work without one as it has no fans of its own. I think the lossnay could be used for fresh air without a GUG though.

Controller

The controller is not too bad, it has a dot matrix LCD and buttons. It is newer than some where they have fixed icons on LCD. It has the obvious controls: mode, temperature, and fan speed. Good.

But, no. The fan speed says "unsupported function" if you try and change it. You need to have a separate "lossnay controller", which basically just lets you set the fan speed.

But there is a 4 wire link cable between the lossnay and GUG, what the hell is that used for? Well, all I can see is that it means is it turns off the lossnay when turning off the GUG. Remember the GUG can only be used with a lossnay attached, this is not some obscure optional extra.

We (myself and the installer) found the setting to tell the GUG it has a lossnay connected (but this unit cannot work without one so why is there even a setting?!), and it shows a nice icon indicating it has a lossnay. But still does not let you control the lossnay from it. Why? Also, the icon looks like it shows the "mode" the lossnay is in (yes, it seems to have a non heat exchange mode, which is pointless) and fan speed, but in fact the icon does not change to actually show the mode or fan speed. How shit is the UI?

Apparently you can run the lossnay without a controller, and the GUG will turn on/off at full fan speed, which is not that useful.

Of course, this also means you cannot run the fan in an auto mode as the lossnay does not know what the GUG is doing. So you cannot have full fan to get to temperature and quiet fan to maintain temperature.

Oh, and crossed zeros. A pet hate of mine. This is not a hand written COBOL coding sheet in the '70s, it is a temperature display. Why make it look like 28℃ not 20℃ to anyone with poor eyesight?

Another gem is that you can turn the temperature down to 12℃, nice, but then it snaps back to 19℃. Why 19℃, that is way higher than I have seen on other air-cons - it will probably do as I would rarely want it that cold. But still, why? And why allow setting below that if it cannot be set lower? Just stupid UI again!

Another thing that seems odd is that the controllers are identical. Same display, and buttons. Looks like identical hardware. The lossnay controller even has a thermometer in it even though it does not need it. But they must have different firmware as they cannot be swapped around. I would have made one controller and made it generic to work anything, but no, they are different!

Setting the temperature

I have upgraded the aircon in my bedroom as the old one broke, and have a nice new Daikin one (as I blogged). I can control over wifi, which is good.

Even though this is way better than the old unit I had, it still suffers from a couple of problems.

Firstly, the good thing it does is finely control the power and fan so that as it gets close to target temperature it lowers the power a bit, and ends up staying on target pretty closely without oscillations. Excellent.

One problem it cannot solve though is the there will be a temperature gradient in the room, not just top to bottom, but also potentially quite a lot if you have a window open a bit to let in some fresh air and ensure the CO2 levels are sensible. Outside was actually below 0 this morning!

The other small problem is that the "auto" mode is not good at some times of year when it will wait until several degrees over target before switching.

To solve the first problem I have an SNMP thermometer with a sensor on the side of my bed where I sleep. This allows me to nicely graph the temperature for a start.

This also lets me take control of the air-con.

First attempts

The first attempt involved doing the job for the aircon - setting the power based on the temperature. However, I cannot do that directly, I have to set the target temperature relative to current temperature to force it to work out a power setting. This took several iterations to get reasonably right.

At one point I was in fact oscillating so much I even had it switching to cooling after it overshot on heating, and then back again later.

But finally after a lot of testing (mostly leaving it for an hour or so on latest algorithm while I did other stuff) I got it oscillating within around ±0.5℃ or so. I was pleased, and slept on it (in a nice temperature controlled room).

On this graph, y-axis is temp in ℃ intervals, x-axis is time in hours, black is target, red is measured temp, light red is setting temp on aircon. The green is reported temp from aircon which I suspect is a separate sensor and way off. So mostly the measured temp was within around ±0.5℃ once it had settled a bit at the start.

Then I had a brainwave..

Finally working (well, so far)

The aircon itself does a better job, holding a much more stable temperature without much oscillation. So use that! I decided to keep a moving average of how far out the setting temperature was from the measured temperature, and use that to add an offset to the target set on the aircon. It only allows settings to 0.5℃ so I added error dither as well.

This works a treat, and allows me to set the aircon allowing for the temperature gradient in the room automatically. The only minor change I made was to offset the averages by a few minutes to allow for the fact that the set temperature does not immediately change the room temperature - so as to better track the actual temperature difference. I was somewhat fooled by how much it changed during the day when sun light hit the room, etc, but I should have expected that.

Here, by using the aircon to control the level we have a smoother temperature. This was in the evening as the outside temperature dropped and so the level to which the aircon had to be set was gradually increased to maintain the measured temperature. Again, within 0.5℃.

The result is all on GitHub (here). It includes MQTT daemon as well (which is how I tell it the air temp from SNMP).

Update: This worked well when the aircon is fighting a window that is ajar. Now I have my new fans installed and windows slows it is oscillating ±1℃, because it is effectively turning on and off at a low level. So I am working on the older method if I find we are doing that. We'll see how it goes. Github updated as I go.

Air conditioning at home (planning permission!)

For many years I used a small stand-alone air-conditioning unit in my study (the box room in the house) and I even had a hole in the wall for the air vent. It just about worked in a tiny room, and needed replacing every few years. In the height of summer I would even put such a unit in the bedroom but that meant a vent out of the window which sort of defeated the object.

However, when my wife finally agreed to my converting the garage in to a "man cave" I decided to do things properly and get a proper split air-conditioning unit installed in the garage (as it was still) and four bedrooms. Yes, overkill I know, but they work well, and they serve to provide energy efficient heating in the winter. I know running air-conditioning has a cost, but it is well worth it for a good nights sleep, and being on a green electricity tariff it is not like I am contributing to climate change either.

Two units are round the side of the house where you cannot see them, but three of them are on the wall facing the road and more noticeable. I did not really think about where they were being put - just left it to the air-con installer to sort them out. In hindsight we could have done something neater and lower down, but he was concerned about children in the garden poking fingers where they should not.

Anyway, this was nearly four years ago now, and they have worked pretty well. Only one unit has developed a fault in that time, which is now fixed.

There can be only one!

Interestingly, a few years ago, someone commented on a picture or video I posted that as I had more than one unit I would need planning permission! Now, planning permission is not something I have had to worry about before, and I assumed only related to actual building work, not simply an electrical appliance. Indeed, the air-conditioning installer had not heard of any need for planning permission and he has installed thousands of these.

When do you need planning permission?

It seems any development needs planning permission, and a development is almost anything that changes the exterior appearance of the property. There are then a long list of permitted developments that allow things without planning permission, and these then have conditions and rules.

So, yes, an air-conditioning unit needs planning permission, but it can come under one of the permitted developments under Part 14 G of the The Town and Country Planning (General Permitted Development) (England) Order 2015. This lists some rules, like a maximum of one unit, not if you have a wind turbine, outside unit less than 0.6m³, not within 1m of boundary, not on a pitched roof, not within 1m of edge of flat roof - pretty simple stuff to be honest. The big one is that there can be only one (but there is a catch, read on).

If you look at air-conditioning installer web sites you will see a lot of companies reference this order and explain that you can have one unit installed without planning permission - yay!

There is a catch!

There is, however, a catch, and it is one even the council seem to be unaware of most of the time, and that is G3(a) states "the air source heat pump is used solely for heating purposes". That's right, an air-conditioning unit that cools, or heats and cools, is not allowed under this permitted development, so even if you have only one, it needs planning permission! Air-conditioning installer web sites do not mention that gem.

Does anyone care?

Well, to be honest, I assumed it would not matter. I mean who really cares?

Well, it turns out someone did! After three and a half years someone, anonymously, complained to the council that we had no planning permission. I mean what the? THREE AND A HALF YEARS!

And no, they won't tell me who complained. Oddly they did think one unit was allowed. I queried this on the basis that maybe they were confused about what I had - after all the permitted development is all about micro generation and renewable energy and wind turbines even, so maybe what I have has nothing to do with part 14 G? They confirmed that air-conditioning units did come unit air source heat pump micro generation! They also confirmed that if it did not then it would not come under any other permitted development so would need planning permission anyway! They then agreed that even one was not permitted if it cools as well as heats!

Interestingly, if it had been over four years after installation it would not matter. Apparently (thanks Neil for finding the reference, here) there is a time limit on these things. That makes the three and a half year delay mentioning it even more odd and annoying.

What next?

Well, I get a formal notice that I am in breach of planning regulations, and a questionnaire. Oddly they said I would have six months to remove them and asked daft questions like how long it will take and why, to which my answer was basically "every last minute of the six months you allow me, Why? Because I like my air-conditioning!". What kind of daft question was that anyway?

The only real option I have, if I want to keep them (duh!), is to apply for retrospective planning permission!

Applying for planning permission...

This is where the real bureaucracy starts! The council web site leads to an on-line application form, which is clear as mud. I eventually managed to make a filing, and paid the few hundred pounds for the application. I had to upload some "plans", a site plan notably, and some pictures. So, I uploaded a google earth view of the house with some arrows added and some pictures. Simple...

After a while they come back and say they need a proper site plan on a recognised scale. Hmm, but hang on, the formal notice I got saying I did not have planning permission had one of those. So I could literally send back to the council the plan that the council had sent me. They clearly have a plan of the "site" on record anyway, but I had to go through this fiasco.

Then they said they needed the size of the outside units. So I measured carefully and sent a detailed email.

Then they said that was not good enough, they needed the photographs annotated with the sizes. Really? OK, I added some arrows to the photographs with the same numbers that I had put in the email!

At this point they felt I had actually provided enough for the application to be submitted or some such, and then I am told the planner is not happy and they want a proper elevation drawing of the sides of the house on a recognised scale showing the position of the units...

OK, losing my patience and the will to live, I engaged an architect for another few hundred pounds to come and measure and do a proper drawing. He did a nice job, and they really could not argue with a proper architect's drawing could they. That worked!

Council planning web site.

At this point the planning application is published on their web site and neighbours are written to. Seems simple enough.

So I kept an eye on the site. It was not made clear to me how this works - do they have a set of rules for such things to which I have to comply, or do I just get permission if nobody objects? It seems a bit like the latter, almost.

Now I know!

Well, there was an objection filed, and guess what - objections to planning permission are not anonymous, so I know exactly who is complaining. The issue is not the units high up on the wall facing the road but the ones on the side of the house only visible from that neighbour (and only one can been seen as trees/bushes in the way of the other one).

Now, these are neighbours who are not usually a problem. We don't know them that well, beyond popping round for drinks at Christmas, etc. But they are the first to come round if they have any complaint, no matter how small. So I am shocked that this one point has taken them so long to raise as an issue! To be honest, we cannot be 100% sure they are the anonymous complainer and not just that they decided to complain once they got the letter from the council.

Their main complaint - the noise! These are really quiet units. No way the noise could be an issue surely, and at the far end of their garden behind some trees/bushes even.

Investigating the objection

So, the council investigate the objection...

One of the first steps was that the person investigating decided to visit the neighbour to hear how loud it was, and told me I did not need to be there. This seems odd, as surely they need me to ensure the air-conditioning is running when they visit. Indeed, a lot of the time the air-conditioning is "at temperature" and not running. If I am not there, then it may be totally off.

Then she said that she needed to check with environmental health to check what noise level is acceptable. But it seems she had taken no measurements or anything.

She then came back to say that I needed to have a noise consultant make a report! And yes, a noise report for all of the units, not just those facing that neighbour. Yet more cost, so I asked what levels were acceptable (in case I need to order a replacement unit that is quieter).

To my surprise she came back and said no noise report was needed, but I had to confirm the units met: "Noise resulting from the use of the plant, machinery or equipment hereby approved shall not exceed a level of 5 dB(A) below the existing background noise level (or 10 dB(A) below if there is a particular tonal quality) when measured according to British Standard BS4142: 2014 at the boundary of any adjoining or nearby noise sensitive premises."

Now call me a cynic here, but the only way I can confirm that is by getting a report from a noise consultant.

I had an alternative idea - I got the spec sheet for the air-conditioning unit and measured the distance to the boundary and sent that asking if it met the above requirement.

Time running out

Then, out of the blue, I am told time is running out - they apparently have a deadline by which to make a determination, and it was coming up! So I had a choice. They would either give me planning permission which was conditional on it meeting that noise spec. Or I could grant an extension to allow them to play ping pong with environmental health.

I double checked, and there is no chance of penalties or fines or anything. So basically I have said give me the permission, and they did. I now have planning permission!

This now leaves the ball in their (or neighbour's) court - they can complain it is too loud and they can get their noise report to prove it. If it is, and they prove it, then all I have to do is turn it off until I change to a quieter unit or re-positioning of the unit so quieter at the boundary.

In practice, as I say, these units are really quiet, so I seriously doubt they fail to meet the noise requirement.

Pondering the stupidity of this law

Having read a bit more, I wonder is there a way I could have done this better? To be clear I have not tried these and do not know the legality of them.

The simplest seems to be to get a shed lean-to on the house. This seems to be something that does not need planning permission from what I can see. Then, in the shed, install outside units for the air conditioning. This is something that does not change the external appearance of the proper and so is not a development and so does not need planning permission - no more than any other work inside the house like installing a new fridge. And also, nobody knows you have air-conditioning units so won't complain!

Another idea was to install one heating only unit as per permitted development. The air-con installer said these units can be set heat only. Then, as a separate thing on a later date you "modify" your existing installation to be heating and cooling. This modification is not something that changes the external appearance of the property and so not a development and so does not need planning permission. If I was only installing one unit I'd rely on the confusion of the council thinking there can be one unit allowed, but have this as a fall back, stating what dates the heating only install was done, and what date the modification was done. I'd probably even make a video of my making the modification. I cannot see how that falls foul of the rules at all, but does rather make a mockery of the rules.

Finally, and most iffy of ideas, was if you want more than one unit. Install one heating only (permitted development). Then install a second along side that is cooling only. Now, this does not break the permitted development on the first unit as there is only one heating unit still, but the cooling one needs planning permission - except there is a general permitted development for modifications to the properly using same materials. I tried that one as a reason to not need planning permission for cooling only and was told "I doubt your house is made of the same materials as the air-conditioning unit". However, because you do have one unit (permitted, heating only), the second (cooling only) unit is using the same materials so should come under that general permitted development. Add a 3rd and 4th as needed on the same basis. Then, one day, change all to heating and cooling as a separate step which does not change external appearance and so is not a development. Would that fly I wonder? If so, the rules really are stupid.

Anyway, what I can say from practical experience, simply budget for planning permission and go ahead without. If you are lucky they will assume one unit is allowed, or nobody will complain for four years. If you are unlucky you have to apply for permission, which seems simple enough! Well, that's my view anyway, even if not my usual "doing it right" viewpoint, sorry.

Conclusion

What a waste of time and money - actually not that much of my time to be honest - and now we have permission. Why did they bother?

We did think the neighbour may be trying to sell, and concerned over the air-con. My house is not the one over which they should be concerned to be honest. But if that was their plan, now they have a neighbour's planning permission "on file" and that will show in a search, so making it far more obvious to any potential buyer. Ooops.