openspaceman

I suppose that 2kW refers to a heating element? We experimented with Coanda effect for gas mixing in our kiln and made several devices well before Dyson came to the market. I came to the conclusion that they conserved momentum but not energy very well so not so efficient. Also I think they are bypass filters as only the higher pressure air powering the blade-less design gets filtered doesn't it. I would like to build a domestic wet scrubber and dehumidifier possibly with an electrostatic stage which would give just a tiny bit of ozone (to match outside air on a sunny day) and so dispatch bugs as well as catch very fine particles. I was taken in by Dyson's multi vortex separators and bag less vacuum cleaners until my colleague and firm's chief designer explained the energy cost, he should know and when we folded went to Rolls Royce and now, twenty years later, is a senior design technician in their gas turbine division. For my part I acquired quite a few Dyson cleaners when they got binned because the filters were blocked, it was a surprise to read that they should not be used with fine dust. I think they are only for clean homes. I have got a few Henry's too which were binned because the power cord fails inside the insulation where it flexes on the attachemnt to the recoil drum.. Replacing the bag is less of a chore than tipping out the dyson container into the bin and getting covered in dust. The HEPA bags are cheap and efficient. I might just get a pre cyclone for the workshop to save on bags filling as per @Paddy1000111's link

Yes that's what I use I was issued with an ash bucket precleaner for cleaning the flyash traps in industrial chip burners, it attached inline with the numatic and most of the fly ash settled into that so the vacuum cleaner filter didn't get clogged, it was all metal in case the ash was still hot, I used it once as it was such a faff to use,

How will you be establishing the weight? In the past it was easy with sawlogs, run a length tape along them and a Qgirth tape around the middles and either tag the end and write the volume in a book or paint the volume on the end.

I put that wrongly, it's particulates that increase during the evening. As it was raining steadily this morning I sampled the outside air, expecting some of the particulates to have washed out but I got figures of ~7μg/m^3 for PM2.5 and 10.5μg/m^3 for PM10, inside the figures were about 2μg/m^3 PM2.5 and 9μg/m^3 PM 10. Bearing in mind PM2.5 are a subset of PM 10 in this device it shows how the smaller particles are almost certainly smoke. There was a big spike of PM10 as I moved the device and then several spikes as I ashed out the stove, all predominatly PM10. So I think that my thought that moving around acauses larger ash particles to be lofted is likely. A long time ago someone, @kevinjohnsonmbe I believe, had a fine filter for indoor air to reduce a family member's allergies? Anyway it is something I am considering but I want to try and make my own. Yes Kevin I have little doubt air changes in supermarkets are too low and some of this will be due to costs of all the lost heat unless they have whole building air heat recovery. I haven't been to a supermarket for a year ( spend a bit more at the corner shop where there are seldom other customers) my wife gets the occasional delivery but as with tube stations, buses and railway carriages I would expect them to be hot spots of virus. I still don't know how efficiently a virus could be filtered out.

Probably but as I said in a post a few days back the outside air particulate level rises during the evening possibly because quite a few neighbours have wood stoves for effect. I really need to keep one sensor running all day inside and one out but I haven't managed to learn enough Python to write a measurement to file every 15 seconds for 24 hours. I would also like to put one sensor the other side of the holly hedge 5metres in front of the house and 4 metres from the road, which is a thoroughfare with a car every few minutes this late at night and delivery vans and buses much more frequently during the day. I don't feel my indoor air quality is a worry but it would be interesting to sense in an all electric house.

@Squaredy there are so many variables and I am probably not qualified to discriminate signal from noise. The "dangerous" particles are probably the 2.5 micron down to 1.5 micron, these are the ones that once in your lungs can get into the cells and blood, most will be exhaled. Most PM10 are trapped in mucous or nasal hairs and eventually swallowed harmlessly. Then there are different chemicals, ash is probably less dangerous than smoke. In my graph the medium peak at 22:17:02 is probably smoke reaching the sensor 30 seconds after I opened the door The other peaks are probably my movement as I left the room for a call of nature a few seconds after I started the experiment and closed the door. This is probably why the big peak is mostly bigger particles of ash dust but I am open to other interpretations.

With old land rovers I managed by jacking one wheel up and chocking the rest, put it in fourth with clutch held down and rev it up and down. The overrun is aggressive as the inertia of the wheel exerts more torque. Back in the day I didn't extract in the winter so the tractor would sometime seize the driven plate to the flywheel. I'd start it up and warm it, throttle down and snick it into 3 low and trundle up the field revving and slowing and stamping on the brakes till it freed with a bang.

This is a problem here as the kitchen is 3 rooms away from my wood stove and I only have the aforementioned induction hob and a traditional 4 hob ceramic one. As an illustration I have just run the particulate sensor. The wood stove has been running all day and the sensor is desk level and 3metres away with my desk and monitor shading it from a direct line. The fire is flaming but dying down to a char bed and I slowly opened the door at 22:16:37 for about 2 seconds. Data below the chart, PM2.5 are a subset of PM10, Some of the peaks are likely from my movement disturbing dust. 13 Jan 2021 22:15:17.552468: PM 2.5: 4.0 μg/m^3 PM 10: 5.0 μg/m^3 13 Jan 2021 22:15:22.541711: PM 2.5: 3.9 μg/m^3 PM 10: 5.0 μg/m^3 13 Jan 2021 22:15:27.541308: PM 2.5: 3.9 μg/m^3 PM 10: 6.1 μg/m^3 13 Jan 2021 22:15:32.541301: PM 2.5: 3.9 μg/m^3 PM 10: 5.9 μg/m^3 13 Jan 2021 22:15:37.541816: PM 2.5: 3.7 μg/m^3 PM 10: 7.1 μg/m^3 13 Jan 2021 22:15:42.542274: PM 2.5: 3.8 μg/m^3 PM 10: 6.9 μg/m^3 13 Jan 2021 22:15:47.542642: PM 2.5: 3.8 μg/m^3 PM 10: 6.8 μg/m^3 13 Jan 2021 22:15:52.542770: PM 2.5: 3.8 μg/m^3 PM 10: 7.0 μg/m^3 13 Jan 2021 22:15:57.543113: PM 2.5: 3.9 μg/m^3 PM 10: 5.7 μg/m^3 13 Jan 2021 22:16:02.543387: PM 2.5: 3.8 μg/m^3 PM 10: 5.9 μg/m^3 13 Jan 2021 22:16:07.543878: PM 2.5: 4.0 μg/m^3 PM 10: 5.4 μg/m^3 13 Jan 2021 22:16:12.543252: PM 2.5: 4.0 μg/m^3 PM 10: 5.6 μg/m^3 13 Jan 2021 22:16:17.542727: PM 2.5: 4.1 μg/m^3 PM 10: 5.6 μg/m^3 13 Jan 2021 22:16:22.542117: PM 2.5: 4.2 μg/m^3 PM 10: 5.6 μg/m^3 13 Jan 2021 22:16:27.540857: PM 2.5: 4.1 μg/m^3 PM 10: 6.0 μg/m^3 13 Jan 2021 22:16:32.539946: PM 2.5: 4.1 μg/m^3 PM 10: 5.7 μg/m^3 13 Jan 2021 22:16:37.538792: PM 2.5: 3.9 μg/m^3 PM 10: 6.2 μg/m^3 13 Jan 2021 22:16:42.537891: PM 2.5: 4.0 μg/m^3 PM 10: 5.9 μg/m^3 13 Jan 2021 22:16:47.537281: PM 2.5: 3.9 μg/m^3 PM 10: 5.9 μg/m^3 13 Jan 2021 22:16:52.536628: PM 2.5: 3.9 μg/m^3 PM 10: 6.3 μg/m^3 13 Jan 2021 22:16:57.535451: PM 2.5: 4.0 μg/m^3 PM 10: 5.9 μg/m^3 13 Jan 2021 22:17:02.534932: PM 2.5: 4.1 μg/m^3 PM 10: 6.2 μg/m^3 13 Jan 2021 22:17:07.534247: PM 2.5: 4.4 μg/m^3 PM 10: 7.3 μg/m^3 13 Jan 2021 22:17:12.533532: PM 2.5: 4.7 μg/m^3 PM 10: 8.2 μg/m^3 13 Jan 2021 22:17:17.532911: PM 2.5: 4.9 μg/m^3 PM 10: 8.8 μg/m^3 13 Jan 2021 22:17:22.532304: PM 2.5: 5.2 μg/m^3 PM 10: 9.8 μg/m^3 13 Jan 2021 22:17:27.531290: PM 2.5: 5.4 μg/m^3 PM 10: 9.9 μg/m^3 13 Jan 2021 22:17:32.530590: PM 2.5: 5.4 μg/m^3 PM 10: 9.8 μg/m^3 13 Jan 2021 22:17:37.530161: PM 2.5: 5.4 μg/m^3 PM 10: 7.9 μg/m^3 13 Jan 2021 22:17:42.529265: PM 2.5: 5.1 μg/m^3 PM 10: 8.0 μg/m^3 13 Jan 2021 22:17:47.528294: PM 2.5: 5.1 μg/m^3 PM 10: 7.4 μg/m^3 13 Jan 2021 22:17:52.527633: PM 2.5: 4.9 μg/m^3 PM 10: 5.8 μg/m^3 13 Jan 2021 22:17:57.527132: PM 2.5: 4.7 μg/m^3 PM 10: 6.6 μg/m^3 13 Jan 2021 22:18:02.526742: PM 2.5: 4.8 μg/m^3 PM 10: 6.7 μg/m^3 13 Jan 2021 22:18:07.526140: PM 2.5: 4.8 μg/m^3 PM 10: 6.5 μg/m^3 13 Jan 2021 22:18:12.525617: PM 2.5: 4.7 μg/m^3 PM 10: 6.1 μg/m^3 13 Jan 2021 22:18:17.525146: PM 2.5: 4.6 μg/m^3 PM 10: 6.6 μg/m^3 13 Jan 2021 22:18:22.524442: PM 2.5: 4.7 μg/m^3 PM 10: 6.5 μg/m^3 13 Jan 2021 22:18:27.523798: PM 2.5: 4.6 μg/m^3 PM 10: 7.0 μg/m^3 13 Jan 2021 22:18:32.523459: PM 2.5: 4.8 μg/m^3 PM 10: 8.2 μg/m^3 13 Jan 2021 22:18:37.522942: PM 2.5: 5.0 μg/m^3 PM 10: 11.4 μg/m^3 13 Jan 2021 22:18:42.522294: PM 2.5: 5.2 μg/m^3 PM 10: 12.4 μg/m^3 13 Jan 2021 22:18:47.522225: PM 2.5: 5.2 μg/m^3 PM 10: 14.1 μg/m^3 13 Jan 2021 22:18:52.521869: PM 2.5: 5.3 μg/m^3 PM 10: 15.4 μg/m^3 13 Jan 2021 22:18:57.521474: PM 2.5: 5.3 μg/m^3 PM 10: 14.0 μg/m^3 13 Jan 2021 22:19:02.520996: PM 2.5: 5.0 μg/m^3 PM 10: 14.1 μg/m^3 13 Jan 2021 22:19:07.520641: PM 2.5: 4.8 μg/m^3 PM 10: 11.0 μg/m^3 13 Jan 2021 22:19:12.520491: PM 2.5: 4.5 μg/m^3 PM 10: 10.4 μg/m^3 13 Jan 2021 22:19:17.520394: PM 2.5: 4.6 μg/m^3 PM 10: 8.9 μg/m^3 13 Jan 2021 22:19:22.519902: PM 2.5: 4.4 μg/m^3 PM 10: 7.8 μg/m^3 13 Jan 2021 22:19:27.519104: PM 2.5: 4.5 μg/m^3 PM 10: 8.1 μg/m^3 13 Jan 2021 22:19:32.518735: PM 2.5: 4.4 μg/m^3 PM 10: 7.2 μg/m^3 13 Jan 2021 22:19:37.518320: PM 2.5: 4.5 μg/m^3 PM 10: 7.5 μg/m^3 13 Jan 2021 22:19:42.518397: PM 2.5: 4.6 μg/m^3 PM 10: 7.1 μg/m^3 13 Jan 2021 22:19:47.518211: PM 2.5: 4.5 μg/m^3 PM 10: 7.0 μg/m^3 13 Jan 2021 22:19:52.518158: PM 2.5: 4.4 μg/m^3 PM 10: 7.9 μg/m^3 13 Jan 2021 22:19:57.518037: PM 2.5: 4.5 μg/m^3 PM 10: 8.1 μg/m^3 13 Jan 2021 22:20:02.517714: PM 2.5: 4.5 μg/m^3 PM 10: 8.5 μg/m^3 13 Jan 2021 22:20:07.518004: PM 2.5: 4.4 μg/m^3 PM 10: 9.0 μg/m^3 13 Jan 2021 22:20:12.517864: PM 2.5: 4.3 μg/m^3 PM 10: 9.2 μg/m^3 13 Jan 2021 22:20:17.517889: PM 2.5: 4.3 μg/m^3 PM 10: 9.1 μg/m^3 13 Jan 2021 22:20:22.518098: PM 2.5: 4.2 μg/m^3 PM 10: 8.9 μg/m^3 13 Jan 2021 22:20:27.517931: PM 2.5: 4.2 μg/m^3 PM 10: 9.0 μg/m^3 13 Jan 2021 22:20:32.517713: PM 2.5: 4.3 μg/m^3 PM 10: 8.2 μg/m^3 13 Jan 2021 22:20:37.517106: PM 2.5: 4.2 μg/m^3 PM 10: 7.2 μg/m^3 13 Jan 2021 22:20:42.516917: PM 2.5: 4.2 μg/m^3 PM 10: 7.1 μg/m^3 13 Jan 2021 22:20:47.516843: PM 2.5: 4.2 μg/m^3 PM 10: 6.6 μg/m^3 13 Jan 2021 22:20:52.516823: PM 2.5: 4.2 μg/m^3 PM 10: 5.5 μg/m^3 13 Jan 2021 22:20:57.516973: PM 2.5: 3.9 μg/m^3 PM 10: 4.6 μg/m^3 13 Jan 2021 22:21:02.517065: PM 2.5: 3.8 μg/m^3 PM 10: 4.8 μg/m^3 13 Jan 2021 22:21:07.517019: PM 2.5: 3.8 μg/m^3 PM 10: 4.9 μg/m^3 13 Jan 2021 22:21:12.516910: PM 2.5: 3.7 μg/m^3 PM 10: 4.7 μg/m^3 13 Jan 2021 22:21:17.516932: PM 2.5: 3.5 μg/m^3 PM 10: 4.5 μg/m^3 13 Jan 2021 22:21:22.516785: PM 2.5: 3.4 μg/m^3 PM 10: 4.6 μg/m^3 13 Jan 2021 22:21:27.516626: PM 2.5: 3.5 μg/m^3 PM 10: 4.8 μg/m^3 13 Jan 2021 22:21:32.516657: PM 2.5: 3.7 μg/m^3 PM 10: 5.2 μg/m^3 13 Jan 2021 22:21:37.516845: PM 2.5: 3.9 μg/m^3 PM 10: 5.4 μg/m^3 13 Jan 2021 22:21:42.517175: PM 2.5: 3.9 μg/m^3 PM 10: 4.8 μg/m^3 13 Jan 2021 22:21:47.517153: PM 2.5: 4.1 μg/m^3 PM 10: 6.4 μg/m^3 13 Jan 2021 22:21:52.517234: PM 2.5: 4.1 μg/m^3 PM 10: 6.6 μg/m^3 13 Jan 2021 22:21:57.517168: PM 2.5: 4.1 μg/m^3 PM 10: 6.6 μg/m^3 13 Jan 2021 22:22:02.517254: PM 2.5: 3.8 μg/m^3 PM 10: 5.8 μg/m^3 13 Jan 2021 22:22:07.517037: PM 2.5: 3.7 μg/m^3 PM 10: 5.6 μg/m^3

It's easy enough to measure electricity usage but mains gas is probably a bit difficult to get accurate when measuring down to seconds. Maybe a propane hob and weighing the bottle before and after. I think I still have a tar boiler hob but no propane in a bottle small enough to go on my scales. Boiling water in a pan in consecutive tests should be good enough for most purposes. Aside from convenience the overall efficiency of electricity would need to allow for the fuel used to generate it. It's a moot point though because I can install a new electric induction hob myself but wouldn't attempt to do a gas one. BTW as we have drifeted a bit from indoor pollution I do not think there would be significant difference between either type of cooking, gas or induction.

This is a major point, conduction from the flame to the pan is inhibited by a boundary layer, generally in the absence of a pan skirt transfer of heat from a flame is around 30%, the induction hob as the name suggests induces it directly into the pan metal. I don't know how efficient the MOSFETS and coils are at creating eddy current in the pan but would expect them to exceed 60%.

I agree and one day I will have a proper induction hob with a full range of controls. I bought a single pan one to see what the induction heating was like and it was great in all respects except even with 9 levels the granularity of control was too coarse. Of course if you do proper stir fry with a round bottomed wok it may be a bit challenging

Any more and I'd drown

The little puff of smoke is what you see and smell, I have done some experiments with my particulate sensor and there is a definite spike of particulates when you open the door and it takes a couple of hours to settle down, I tend to have to add logs every hour or so. What surprised me was when I put the sensor out of the window the outside air was worse for particulates then inside and I cannot decide if it's my smoke I am sampling (no smoke visible in daylight from my chimney) or my neighbours. I light my stove each morning and I'm fairly sure my neighbours only light theirs in the evening.

After my antics in the mud today I'm beginning to wonder if I'll get that far.

Did you have any of those wobbly toy figures which when you flicked them always wobbled back upright? A tree is like that, the soil entrained by the root system is a great big weight hanging over the hole from which it has come, this is counterbalanced by the stem and top, so there is a massive bending moment in the area between root and stem waiting to release a lot of force. Sometimes the tree falls over with a shallow roots and ends up jacked off the ground with the rootplate towering over the stem, cut it on the wrong side of it's balance and the stem drops to the floor and the rootplate falls the wrong way burying you.

https://www.forestresearch.gov.uk/documents/1963/FCBK039.pdf

Margaret read what @Mick Dempsey says, wait and see. Height has been reduced even though it's not well executed work but the tree will recover and in summer it will still be hiding some of that concrete roof. Keep that conifer hedge regularly trimmed too, else it will grow out into the garden and become too late to recover. The tree has sprouted from a stump anyway which is why there are so many stems

Probably and something else from those black lines (pseudo schlerotic plates?) was entry from that bark damage showing compensatory wound occlusion at the bottom of the photo?

The one above looked like elm. I wonder if spring summer felled oak gets more mould than winter felled as there are less sugars in the sap, not there is less mould on the heartwood.

Sorry I don't know but personally would risk 1 metre. How does the cost compare with fitting the sealed air kit? I just looked and £49 so for the sake of a core drill, flexible exhaust pipe and that...

Not a problem and nothing to disagree in that post, I have never thought about toilet cistern overflows but modern ones are internal and into the bowl.

For some reason Neil's new content got attributed to me. The only thing is that the problem may well be because of wind conditions around the house, my thoughts on an internal circulation was just another possibility

I was saying what my ancient one would do but your other points make sense. Also bent logs increase the depth of cut required. Other than my little mitre saw, which I intend to cut some old steel bed frames with, I have not used a TCT blade, nails should be no big issue I still prefer the circular saw in the processor but the only chainsaw one I used was the Japa with a belt driven chain IIRC. I have lost a couple of finger nails with my circular saw snatching the log and with the log jamming the blade, a chainsaw just stops in the same circumstance. I used a segmented belt as it slipped more easily. I haven't used it for many years

15 rose/briar 14 horse chestnut, (aesculus hippocastrum) 13 Ivy,(hedera helix) 12 rose/briar 11 ivy aerial leaves 10 soft rush (juncus efusa?spelling) 09 ivy berries 08 elder 07 bramble 06 possibly old nettle stems 05 ash (Fraxinus excelsior) 04 ash keys 03 ash 02 haws 01 haws, bramble leaves and briar stem

trouble is they need to be 750mm diameter to cut 230mm but faster than a chainsaw, just as easy to sharpen with a file, unless TCT, but have to be returned to a sawdoctor to retension and gullet. When things go wrong they are more trouble than a chainsaw.