Jeremy Harris

Interesting that it does use Zigbee networking. Sadly there's virtually no chance you'll be able to sniff it and make any sense of the data, as it uses 128 bit encryption, so is pretty secure.

Glad to hear that Mikee has got some sort of resolution. I felt very sorry for him at the time I was booted off the GBF, as I felt he needed some strong encouragement in order to try and steer his case in the right direction; he always seemed a bit too willing to listen to what I thought was some pretty dubious legal advice regarding his case for nuisance. Let's hope the new chimney at least partially resolves his problem. I doubt it will completely fix it, as wood smoke will always tend to settle when there are local down drafts, as I think was the case where he was.

The quick way to check might be to just look at the board inside. I very much doubt they use the Zigbee protocol, as there is no network connection-type requirement. Our wireless thermostats use a standard 868 MHz RF module, with what looks like a proprietary 28 bit protocol. Sniffing it was easy enough with an 868 MHz receiver hooked up to a microcontroller serial port, and storing a snapshot of the Manchester encoded bit sequence, but decoding it was beyond me. I have managed to decode and remotely operate the Byron/HomeEasy 32 bit 433 MHz protocol, but only with a great deal of help from others. I successfully managed to build both receivers and transmitters that would work with the Byron/HomeEasy home automation units, but never got so far as to emulate the learning mode these things had, so had to sniff every transmitter/receiver pair to determine the actual initial address sequence. Most of the data transmitted by these devices is aimed at reducing interference, because there is only a very limited amount of bandwidth available and there is also a great deal of other stuff working on the two bands that this type of device works on. Once you've got hold of the protocol used, and the address format, getting controls to switch on or off is easy, just a single bit change in the 32 bit command sequence in the case of the Byron/HomeEasy units. I suspect other systems use something very similar.

Doesn't it just! The safety edge and door closed sensor on the bottom of our garage door uses an 868 MHz transmitter, powered by two very expensive and relatively hard to find lithium batteries. These last about a year and a half before needing replacement. The cells are around £3 each, so about £6 every year and a half, just to keep the garage door working (it locks out when the safety edge batteries go flat, and has to be manually operated, which is a real pain). The batteries go flat even if the door isn't used, as the transmitter is on all the time, it seems.

I remember it starting, back before I was kicked off the GBF (for reasons still unknown, or at least, suspected, but not proven). The poor chap was in a bit of a nightmare neighbour situation, IIRC, with the neighbour having an inappropriately positioned wood burning stove flue, with smoke being blow down to ground level and into his home as a consequence. I think the problem was compounded by the neighbour burning old pallets and treated/painted timber. It was very clearly a case of public nuisance, yet, for whatever reason, the local authority seemed reluctant to act. Had it been me, then I would have gathered the evidence as that chap did (he went so far as to buy pollution monitoring kit, iIRC) and I'd have gone straight to court, suing the neighbours for causing a nuisance. I seem to recall that the environmental health bloke was a waste of space, and kept repeating the mantra that as the stove was installed by a HETAS approved installer, there was nothing they could do, which is a load of rubbish, as HETAS has nothing to do with public nuisance, AFAICS.

That aligns with our experience in our old village over the past few years. Being set in a deep valley, in cold, still weather the smoke from wood burning stoves (and open fires and bonfires) would settle and fill the entire valley with smoke. Coupled with mist coming off the stream the air would often turn into thick smog. The Parish Council, and many residents, tried for years to get the local authority environmental health people to tackle the problem, with no success at all. In the end it was the police and court that settled it. There was a serious road accident, and the cause was determined to be the very poor visibility due to the thick smog bank near bridge over the stream. This got the council's attention, when all the evidence of the many complaints about the smoke problem, and the lack of action by the local authority, surfaced during the accident investigation. Within weeks we had both a bonfire band imposed and regular monitoring of smoke, with those producing it told to cease and desist. Given there was mains gas in the village, and that the cost of fire wood is now very high around here, this combination was enough to get people to stop making smoke.

I'd hard wire, too, for two reasons. Firstly, there are only a very limited number of licence-free wireless bands, and WiFi and things like wireless thermostats, car remotes, remote light switch systems etc are using up all that bandwidth very rapidly. As an example, my garage door has two wireless links, one for the remote, one for the door sensor, both operating in the 868 MHz band. My car remote locking, continuously transmitting transponder sensing (for the keyless entry) and the remote air conditioning controls in the car also work in the same 868 MHz band. The excess PV diverter box has yet another 868 MHz transmission, to control the remote power switch. The wireless thermostats use two data links operating in the same 868 MHz band. The kitchen lights use a couple of wireless links that operate in the 433 MHz band. The CCTV alarm also has a data link that operates in the 433 MHz band. The indoor energy display also works in the 433 MHz band. The door bell also works in the 433 MHz band. The CCTV video transmission works in the 5.8 MHz band, and the WiFi works on both 2.4 GHz and 5 GHz. We have two separate WiFi networks in the house, one dedicated to CCTV. Locally, when scanning around every single spot frequency in the 2.4 GHz band has traffic on it, from all our neighbours WiFi systems. The 433 MHz band is a nightmare, with literally hundreds of signals, some very intermittent, like remote light switches, some regular, like the weather station one of our neighbours has set up in their garden. The 868 MHz band is a little bit better, that's mainly just sporadic car remote control signals. The 5 GHz WiFi band is getting quite congested, not as bad as 2.4 GHz yet, but getting there. My guess is that this is due to the gradual spread of dual band WiFi. Secondly, any wireless connection, no matter how robust, is subject to jamming or hacking. It is just about impossible to prevent a determined person from interfering with a wireless system. Even very secure, rolling code, car security systems can be very easily hacked - witness the increasing number of car thefts from homes where transponder amplifier boxes bought cheaply from the internet have been used to unlock and start keyless entry cars and drive them away. For me, I would use wireless only where there is absolutely no practical alternative, but would choose to use a wired system when it's easy to install, such as during a new build. The reason the installers like wireless systems is that they are a LOT less work to install, so less hassle for them, and less time on the job.

Why is the Clean Air Act so hard to enforce? I remember when the area in Gerrards Cross that we lived in back in the 1960's was made a "smokeless zone". No one would sell ordinary coal there any more, only the new "smokeless fuel" (essentially some form of coke briquette, I think). Back then the council were pretty hot on reporting people who were found to have smoky chimneys, so if they could do it back then, why not now? I can remember staying with my grandmother in High Wycombe in the 1950's and having to walk down the street with a handkerchief over my face because of the thick smog, partly caused by the coking plant that produced town gas that was in the middle of the town. Smog killed people every winter back then, and memories of the "Great Smog of London", that killed thousands in the space of a few days, were still very clear. Perhaps that's why the council were so proactive about stopping people creating smoke. Given that all wood burning stoves emit high levels of particulates at some point in their operating cycle, and conventional wood burning stoves emit high levels of pollutants pretty much all the time they are running (even the best are many, many times worse than a diesel car), it should be possible to just prohibit their use, following a simple complaint or discovery that firewood was being delivered to a property.

Thanks, @Nickfromwales, those first photos look exactly like the "periscope" arrangement on the house down the road, and are exactly what I was thinking of. I shall try and remember that they are called plume management kits! It looks easy enough to retrofit one of these to an installation, looking those photos, so my guess is that one may offer an easy fix for the problem that @Grosey is having.

@Nickfromwales can confirm this, or otherwise, but you may be able to fix this with a flue extension. A new house was built up the road from us a couple of years ago, and they had to fit a sort of "periscope" arrangement to their boiler flue, to avoid it blowing out across a footpath, and something like that might be a solution for your problem.

I reckon that's why our landscaping guy calls them "puncture seeds"....................

Depends on how much heating your house needs, and it's also important that it doesn't need cooling (a combined heating and cooling heat pump isn't RHI eligible). The main issue is that to claim RHI for seven years the installation has to be undertaken by an approved installer and the kit has to be heat only. In our case, with our small ASHP, the additional cost of the approved installation was going to be at least a couple of thousand pounds, and the RHI payments were going to be around £80 a year or so, for 7 years. So, if we went for an approved installation we would have incurred an additional cost of at least £2000, in order to get a payment totalling less than £600 over a 7 year period. In order to break even, with the RHI just recovering the additional installation cost, our heating requirement would need to be more than three times higher than it is, and even then it wouldn't make sense, taking the 7 year payment time into account. I can't say that I think this change will change things, at least for those who have pretty low heating requirements. The RHI is only really of benefit to those whose houses, at least on paper, have a fairly high heating requirement.

As an aside, one thing I REALLY regret is not having split our house wiring into essential and non-essential circuits, with separate feeds for each. I would then have fitted a changeover switch on the essential circuit to allow either a generator or battery bank and inverter to provide power in a power cut. It would have been easy to do when running the first fix electrics, but a real pain to do now.

Part F could be clearer, I think, as the minimum continuous ventilation rate allowable with MVHR still seems much higher than the likely natural ventilation rate without MVHR. It seems fairly common to hear of people with passive houses turning down the background ventilation rate once they have a completion certificate, on the basis that the rate in the regs is higher than needed. I'm not convinced that this is wholly down to the number of occupants in every case, either. Getting back to heating using ventilation air, then if deciding to do this the system has to have significantly greater air flow capacity, which means bigger ducts and terminals. Air can only move a tiny fraction of the heat that water can. Very roughly, for a given amount of heat transfer you need to shift around 3,400 times more air than water. This explains why air heating systems use big ducts and water heating systems can get away with using small pipes.

I spent ages picking up nails. I had a load of 20mm diameter neodymium magnets, the ones with a countersunk centre hole , that I'd used as door latches. I screwed a row of these to a batten, fixed the batten at right angles to another to make a thing that looked like a broom with no bristles and wrapped an inside out carrier bag around the head and taped it in place. Just dragging this across the site picked up loads of nails, mainly nail gun misfires, I think. The carrier bag is there so you can just untape it, turn it the right way around and pull off all the nails the magnets have collected. The landscaping chap watched me doing it, said nothing for a while, then came over, looked in the bucket of rusty nails I'd collected and said "What are you doing then, collecting puncture seeds?"

The default SAP air permeability isn't 15 ACH at 50 Pa, it's 15 m³/m²/h at 50Pa. There's a big difference between the two methods of measurement. SAP is, as far as I know, the only energy efficiency assessment method that uses these units for air permeability. Pretty much everyone else in the world, including the PassivHaus Institut, use air changes per hour at 50 Pa pressure differential.

Being possible to heat using a heat source in the MVHR and being desirable and practical to heat this way are two different things. Firstly, an MVHR running at normal ventilation rate will take over 2 hours to change all the air in the house. In practical terms, this means that heating the house from cold with such a system can take many hours. This isn't too big a problem if you never let the house get cold. However, even a passive house needs heating in very cold weather, and it's very likely that the background airflow from an active MVHR with duct heating will be too low to meet that heating requirement, so the air flow rate will have to increase. This can be a nuisance, as increased flow rates tend to create a little bit of noise. This noise is acceptable when the MVHR boosts when showering or cooking, but may be an issue at other times. We use our active MVHR for comfort cooling, and the slight noise increase from the higher flow rate when it's in this mode is noticeable. Not enough to be a daytime nuisance, but I would rather not have this slight noise at night time. Luckily there's no need for active comfort cooling at night, as the house will have cooled down enough during the day, and the MVHR on full bypass is enough to keep the bedrooms comfortable. Secondly, heating the air in the house tends to both make it a bit uncomfortable, and also tends to take a very long time to get the floor surface temperature up. We've found that we only ever use the very low temperature ground floor UFH when heating is needed, and are convinced that heat coming from the floor is a great deal more comfortable than heat coming out of the air vents. We have no heating on the first floor, except towel rails, on timers, in the bathrooms. I did fit fused outlets for small panel heaters in the bedrooms, but never fitted the heaters, as they aren't needed. The UFH is absolutely superb. It runs at a very low temperature (typically 22 to 23 deg C) and can not only warm the ground floor slab in winter, but can cool it to around 18 deg C in summer. For the very modest additional cost of 300m of pipe cast into the passive slab it was one of the best investments we made. Not only is having a slightly warmer than ambient floor very comfortable, it also acts as a large storage heater, so in very cold weather the UFH comes on for maybe an hour each morning, sometimes every other morning, and the house stays at a nice, even, temperature.

We had a big problem with cluster flies in our first house in Scotland. It was right next to farmland, by the shore of Loch Ryan, and the window frames would be full of the things if you opened a window. They would crawl in though the narrow outside gap and gather in large numbers in the small sheltered space outside the inner seal. I found that the paint-on stuff worked well. Not sure of the name of it, but you just open the windows and paint on a thin layer of the stuff around the hidden areas. It seemed to last for around a year, and either killed, or dissuaded, cluster flies from crawling into these spaces.

I did both my design SAP and as-built SAP, but had to pay an assessor £100 to check my as-built file and lodge the EPC. I used FSAP to do mine, not that hard to get to grips with. I passed the design SAP details to BC and they were perfectly happy to accept my own work at that stage, it's only for the as-built SAP where you hit the monopolistic business that only a registered assessor is allowed to submit the chit. A typical, over-regulated, government job creation scheme, in my view I've just checked and the design EPC was A102, the as-built EPC was A107.

It's certainly around the right figure to have been derived that way. Our Genvex unit could pretty easily maintain the house at a comfortable temperature in winter, but I would need to increase the ventilation rate in very cold weather just to get enough heat through the ducts. I think we have to remember that when the PH standard was being put together all those years ago (around 35 years ago IIRC) there wasn't much data to go on. I think that it was seen as the time as being a very challenging target, using the construction methods that were in general use back then, whereas now it's not at all hard to meet the standard, or just have a house built from one of the suppliers that offers PH level insulation and airtightness as part of a standard package. One thing I've found is that both the PH and building regs Part F background ventilation level seems higher than needed to maintain good air quality, so I suspect that this may be another number that was pretty much plucked from nowhere. I very much doubt if there are many, if any, non-MVHR fitted houses that come anywhere near meeting the background ventilation level that's in Part F for an MVHR equipped house, for example.

I wonder how they are getting past the main intake filter? I changed our filters and cleaned the housings out a couple of weeks ago, and as usual the intake filter box had a fair few cobwebs, dead flies etc in. Given that this filter can filter out pollen, I can't see how those harvest flies could get through. As @jack suggests, this indicates that there are gaps around your main intake filter somewhere, and that the harvest flies are getting past it and being drawn in by the fan. They will easily get sucked in by even a low suction, as they are not powerful fliers. I managed to fill our bedroom with them when I was positive pressure air testing our old house; my home made fan sucked hundreds of them in, covering the walls etc with little black specs. It took me ages to clean them all up before SWMBO came home.................

Our PV is 6.25kWp, EPC is A107. I think I did work out the EPC without the PV, and it was still in band A, but I don't have the file on this laptop to check the actual number.

I fitted an extract in our services area. It didn't really help the overheating problem we had in there when we had the thermal store, but it did noticeably increase the inlet temperature at the MVHR main extract side, so also increased the fresh air feed temperature a bit. The overall effect on the house was tiny, mainly because MVHR isn't really much use for redistributing heat, but I still think it's worth doing, for the sake of a bit of duct. Ours doesn't even have a terminal, the duct just pokes up to near the highest point in that area, but that's really because flow adjustment with our system is via restrictor rings fitted inside the plenum chambers.

No, is the simple answer. The air coming out of the fresh air vents will always be colder than the air being extracted from the extract vents, so the MVHR will always tend to cool the house down, but it will cool it down a great deal less in cold weather than normal ventilation. If you fit either an active MVHR, with an air-to-air heat pump (like the Genvex unit we have) or if you fit a post-heater in the fresh air duct, then you can provide a very limited amount of heating, but this is really only suitable for passive house type heating levels. For example, our Genvex can provide around 1.5 kW of heating, more than enough to keep the house warm, but it cannot heat the house quickly, as it only moves less than half a house full of air per hour. As a consequence, it could take hours to heat the house from cold using this system, but it could maintain the temperature easily enough once the house is warm. The reason we don't heat the house with it is that it tends to make the air very dry, so we only use the Genvex for comfort cooling in summer, not winter heating.

When I emailed the EPC and air test chit to the BCO, this comment was a part of his reply: Later I had an email from the council energy policy officer, asking if he could come around and have a look, as the BCO had emailed him about this odd house in Wiltshire with a silly EPC rating....................