openspaceman

It's not Friday night so what's the excuse?

That's the worry; if I use all my hardwood this year and fill with cedar next summer I may run short again as I only have 8m3 of covered storage. @Dom who doesn't post here any more says it will take 2 days to get down and it looks about 150Hft plus a third that again in branchwood so it will fill me up and some. There's just about room for a straight fell but the logistics of dragging the top out to the chipper make section felling more sensible and less damage to the lawn, also I'm not that brave or confident any more.

I've ordered one, I could not allow myself to be part of the excuse to increase the wages of the top bods at Hetas so got a deal a couple of quid cheaper online.

I can't as I have no dry wood left. Except some of the beech felled and split in February is just about fit to burn. Looks like the following year will be cedar as I looked at a large deodar today.

The reason for the RH and temperature logger at the top is to see how much of the heat is wasted and how much unsaturated air is being exhausted. There is a dimensionless term called the Biot number which describes how a heat gradient applied at the surface will put energy into the middle. It is used for determining how hot a body will get in free space over time. I suspect the biot number for grain and sawdust is much less than one, hence they accept energy easily and that for logs much greater than one, so they don't deliver energy into the middle very well .

Thanks to @Dan Maynard I was able to save a logfile and produce a chart for about 11 hours today, some 8000 records. Below is the result from outside the front window of this room 1.2m from the ground, 6m from a holly hedge and a further 6m to a minor through road. The results are for pm2.5 in microgram per m3 of air. I did not operate any machines (deference to Sunday) but did light the stove at 20:15 just to see the result as it was fairly warm this evening. From the timing of the other spikes I suspect local barbecues but I was out most of the afternoon.

What would be interesting is to put a temperature and RH data logger just under the top layer of logs, one on top of one of the floor vents would be handy too.

Seems to be a popular pastime, best not say anything about PPE

have you considered branch loggers?

That's an interesting post @Squaredy; plainly you don't *need* to heat the logs to a high temperature because passing low relative humidity air past the log surface will remove water. What the higher temperature does is to increase the rate at which the moisture moves out of the log. So yes high temperature leads to quicker drying but also increases heat loss. When running at the higher temperature if you don't pass the hot low RH air over enough logs it remains warm and unsaturated, hence if you exhaust it you waste energy. This is why many kilns will recirculate air and exhaust a fraction as cooler saturated air. With the grain floor you only have one pass so the air needs to pass a lot of wood surface area to saturate, as it saturate it cools so even if you pass 80C air at the bottom if the stack is deep enough it will become saturated and cool before it exhausts at the surface. I suspect with logs it would need to be infeasibly tall. My old boss's design took low grade heat at 40C so that vented at ambient after doing its drying with very little energy loss other than in the enthalpy of the water vapour.

I didn't use the pi directory just logged it to home, it didn't like the string μg/m^3 in line 43 but worked when those were deleted. Thanks, perhaps we can chat about it some time?

My understanding is these floors have a plenum underneath and then slotted floor for the warm air to pass up through. When there is loose grain on the floor the air is distributed fairly evenly through the grain, also only 2-5% of the mass is exhausted as water vapour. With wood, especially in IBCs I wonder how much of the air will take an easier path between the containers. Also the air only passes through once, with grain that is ameliorated because there is a very high surface area and the moisture doesn't take too long to pass to the surface of the grain. With wood unless you have sufficient moist surface the air will leave the top less than optimally saturated. If you are blowing ambient air the only issue is the fan power but if you are heating the air then it could be leaving the surface still too far above ambient temperature which means heat is being wasted. My old boss built a number of wood chip dryers based on this principle of dry warm air fed in at the bottom and colder saturated air being exhausted and it's an art deciding when the wood at the top is nearly dry because whilst the bottom layers become in equilibrium with the incoming warm air saturated colder air can actually redeposit moisture into the top layers. With woodchip this is visible and obvious but I don't know with logs.

My second try at posting a reply; I have used Hep20 with push fits for DHW but never joining old imperial. I would use a push fit to compression adapter and a 3/4" imperial olive, chiefly because I am poor at soldering wet fittings

Yes, similarly nightjars look like raptors

Not heard a cuckoo here for much longer than 10 years. Normally manage to hear one when working further south and in woodland but getting fewer and fewer. Last time I remember seeing one was working on a dairy farm 48 years ago

Can you send me the python you're using, or if you tried then what was the problem? Writing to file is reasonably straightforward. The problem is I do not code, not since fortran4 and a little O for a Psion. I adapted someone else’s code a long time ago and cannot remember what or how I did it. See below: #!/usr/bin/python # -*- coding: UTF-8 -*- import serial, time, struct, array from datetime import datetime ser = serial.Serial() ser.port = "/dev/ttyUSB0" # Set this to your serial port ser.baudrate = 9600 ser.open() ser.flushInput() byte, lastbyte = "\x00", "\x00" cnt = 0 while True: lastbyte = byte byte = ser.read(size=1) # print("Got byte %x" %ord(byte)) # We got a valid packet header if lastbyte == "\xAA" and byte == "\xC0": sentence = ser.read(size=8) # Read 8 more bytes # print "Sentence size {}".format(len(sentence)) readings = struct.unpack('<hhxxcc',sentence) # Decode the packet - big endian, 2 shorts for pm2.5 and pm10, 2 reserved bytes, checksum, message tail # print array.array('B',sentence) pm_25 = readings[0]/10.0 pm_10 = readings[1]/10.0 # ignoring the checksum and message tail if (cnt == 0 😞 line = "PM 2.5: {} μg/m^3 PM 10: {} μg/m^3".format(pm_25, pm_10) print(datetime.now().strftime("%d %b %Y %H:%M:%S.%f: ")+line) cnt += 1 if (cnt == 5): cnt = 0

it's a fudge IIRC but somewhat along these lines: Old 1/2" was internal diameter but with a wall thickness of 1.15mm became metric 15mm O.D. 3/4" I.D. has a slightly larger wall thickness around 1.2mm and becomes 21.45mm O.D. 1" I.D. with a wall thickness of 1.25mm becomes 27.9mm O.D. The difference is all taken up with the olives so to connect an imperial pipe to a metric fitting you need the imperial olive

The bright orange one? I could never start it by myself, I needed someone to drop the valve lifter decompresser thingy. I still cannot remember what happened to it.

The interesting thing about that site is they do not discriminate between domestic burning, industrial burning and bonfires. RHI must have significantly increase woodchip stokers and from experience I know they often get delivered well out of spec chip moistures content. I went to Data Archive - Defra, UK UK-AIR.DEFRA.GOV.UK to try and grep some hourly data at various seasons for one site but had not much success as my various terms brought up null data. One day I will get my particulate monitor recording to file and run it for 24 hours.

Didn't you say 67 yesterday? It's a fair analogy, my mother could recite a poem from "Flax of Dream" right up toward the end but not remeber anything from the past week. SImilarly my brother would recite a love poem to his wife from 50 years back but not remeber his way to the bathroom shortly before he passed away.

You have the experience so I'll accept that figure. When I was harvesting timber I reckoned it cost me about £2 per green tonne to do anything like moving it from stack to transport, perhaps I was being generous but with a "cube" of firewood containing say 0.5 tonne of green wood there's £1 spent getting it in and out of the Kiln, then there's the cost of energy to run the kiln. I suppose once it's in 1m3 containers that handling cost goes down a bit?

I would never expect to burn wood from end April till October but apart from a few days in April am still lighting it late evening. This is the first year I've really tried to maximise wood heat and minimise gas in this small semi detached cottage and have got through a log shed full, that is 8m3 stacked. I reckon that saves me about £350 in gas but it values my time preparing wood quite lowly. Given where you are I'm not surprised

Is this the colour change one that comes in at £24.50 delivered? Any foibles? I may lash out and try one for the first time, then do some tests.

Well HETAS (the owner of woodsure??) published a weak rebuttal and this page Government overestimating emissions from domestic wood-burning, says industry body - Air Quality News AIRQUALITYNEWS.COM A report commissioned by industry body HETAS claims that particulate matter emissions attributed to domestic... ends not supporting them. I guess the only way to get a figure on this is to find some 24 hour emissions data for different times of year. What we can say is that particulate pollution from other sources has declined for various reasons including catalytic converters and DPFs on vehicles so with no changes in wood burning the percentage contribution was bound to rise.

Most of these pumps are a cylinder with a piston rotated by a worm gear, as it rotates the piston moves in and out on a stationary cam. On the power stroke oil is delivered out the cylinder via a small hole, on Stihls this cylinder can be inserted wrongly so the output hole does not line up with the oil gallery. I am not familiar with the 240e.