openspaceman

58 minutes ago, Billhook said:

The whole World seems obsessed with the smaller details rather than the bigger picture

Yes , there are arguments about particulates but there seems to be no joined up handwriting.

Agreed

58 minutes ago, Billhook said:

At the same time as banning some of these lesser pollutants there is far too much air travel and driving around in cars with massively unnecessary horsepower all capable of sub nine seconds to sixty and three figure top speeds.  Unseasonable foods coming in from all over the globe, massive waste of food by selective size, quality and Best before dates.  All costing the environment and natural resources a great deal to grow only to throw away.

Yes we are profligate with fossil food because it is commonly available and as such subject to the tragedy of the commons.

58 minutes ago, Billhook said:

But way above all of this is the pollution caused by military training and warfare.  God knows how much energy is consumed every time a Eurofighter is scrambled let alone dropping a bomb in Syria.  Every bomb dropped is probably equivalent to the whole emissions of all vehicles in London for a month.....a year even.

A few years back I corrected someone about whether volcanos produced more CO2 from  their activity than mankind,s combustion of fuels, they don't. In this case I think you are probably right but if we are talking about particulates, with the exception of fine dusts carried from arid regions, most particulates settle out or are diluted quite quickly, 200metres from a busy road  attenuates exhaust particulates to ordinary background,

There is a problem in the above in that we now know it's particlates between 1.5 microns and 2.5 microns that are a bigger problem and they likely travel further, dust is also a lesser toxiity to particles of incomplete combustion.

58 minutes ago, Billhook said:

Going back to the question of burning wood, we grow several acres of miscanthus here which has taken the place of coal at Drax power station.  I am sure that there are tons of particulates released each year from this process but we are saving our coal resources.  Will miscanthus be banned as well?

I would expect the furnaces at Drax to have complete combustion, so no Products of Incomplete Combustion to speak of. PICs are formed when a flame doesn't have time  to complete and the conditions in a large burner have the right time, temperature and turbulence to ensure good combustion. They will aslo have stack filters including electrostatic and wet scrubbers to remove fly ash and heavy metals.

12 hours ago, Woodworks said:

I have said before but I think you need to check your moisture meter. Totally impossible to obtain the percentage level you are talking about here. Wooden furniture in centrally heated homes is rarely below 10%.

 

The billets in the pictures below are oak and douglas fir. Both 3 or 4 years old on pallets with a rain cover

 

Current temp here is 17C and RH is 89% so by this table the driest a log could be is 19% https://www.woodworkerssource.com/shop/mois.html

 

You say you are east midlands so if we take a weather station up there https://www.wunderground.com/personal-weather-station/dashboard?ID=IENGLAND1344  which had an average temp of 16.4C and average humidity of 86% today you end up with wood at 18.4%. Below 20% just but we are in a fabulous spell of summer like weather not exactly representative of winter. If you are all for kilned dried only then yes bang on about 10-15% wood for fires but if want air dried to be on the market please dont encourage unachievable targets. 

 

11 hours ago, gdh said:

That's my thoughts to, we've kiln dried to less than 10 and stored undercover it consistently goes back up to 17%.

This is my thinking also but again I'm a bit wary of meters as I think some measure moisture content on a dry weight basis.

On a similar theme; I have two pieces of wood, ash and spruce both about 200 grams, sitting indoors by my desk, which I dried in the oven on 5th of March, they are increasing in weight by about 1 gram a month and are around 7% mc wwb.

15 hours ago, difflock said:

Anyway bringing the firewood in to the house/beside the stove for at least 24 hrs before burning, makes a vast difference.

That would occupy a fair amount of space in my front room, at least an armchair's worth and that wouldn't have much circulation to make a change in 24 hours.

12 hours ago, Alycidon said:

At the time the max MC acceptable was 25%,  that is far far to high,  yes they have brought that down to 20% but ALL stove manufacturers require a maximum of 15%, some 16%.     So 20% is still for me far to high,  they are being corralled by CW whose KD moisture warranty was last time I looked 20% - 22%.

 

Do you know how any of their figures are arrived at or justified, Is CW an abbreviation for the Snell bros operation in Hereford?

As I tried to demonstrate in a recent post about attributing efficiency it actually doesn't say a lot about how a stove in normal use heats the occupants of a room.

9 hours ago, kevinjohnsonmbe said:

I appreciate, for volume, it can be represented as necessary.

 

Yes and it is straight forward to attribute costs if you know them, such as storage, opportunity cost of labour one season versus another, cost of cashflow, cost of fuel used, amortisation of drying plant etc. Even with solar drying on a large scale there will be an electricity cost for forced ventilation

9 hours ago, kevinjohnsonmbe said:

I’m only viewing from a self-sufficiency perspective and with the luxury of low volume, sufficient time and ample space for ‘natural’ processes.

Which is how most of us dry wood for our own consumption, that's not the marketplace

9 hours ago, kevinjohnsonmbe said:

 

  I can understand the situation of trying to achieve product, on time and to spec, in bulk, but it just doesn’t “sit” right with me. I struggle to believe there was ever the intent, when RHI was conceived, for it to be used in this fashion

Which is true of any distortion in the market, people will take advantage whether it's by smuggling, black market or in this case to maximise RHI.

1 hour ago, Craig. said:

Can`t help with removing the master cylinders, but I seen to recall that they don't use normal brake fluid.

That's right, like other JCBs it uses a mineral oil in the brake circuit. I'm not sure whether this one failed from seals reacting to wrong fluid or simple contamination by crap.

Has anyone experience of replacing the master cylinders on this old telehandler? On first look it seems the whole binnacle with pedals, instruments and steering  control has to come off the get at them.

43 minutes ago, Paul in the woods said:

and they seem to have traced it to wood burners.

Paul I'm running late so only comment on one part of your post, they have not traced anything. They have reason to believe that particulates are vectors of disease and they have made a leap to attribute all particulates of all sizes from any source and given them an equal rating for toxicity. Medical practitioners looking to fund their careers in research have conflated particulates with killing people. Yes there is no known safe lower limit for particulates in the atmosphere but there is also no direct correlation with all particulates of all sizes and disease.

40 years ago you would see a blue haze rising above cars idling at traffic lights, rubbish tips were deliberately burned and most people smoked plus we allowed stubble burning and gardeners burned rubbish, look at what's changed.

44 minutes ago, Rough Hewn said:

I'm told it's illegal in France to have any sort of bonfire anytime of year now.

 

the human respiratory system has some defence against wood smoke. But look into what's happening in Africa and Asia about air pollution in huts with no chimney.

serious breathing difficulties and lung problems after decades.

new designs of mud/stone/clay which are similar to rocket stoves are much cleaner burn, which then increases longevity.

In fact the recent studies in Malawi where a large group were given clean battery powered stoves to use did not find a significant difference in health of under 5 year olds  in the years of the trial. The population was so poverty stricken and malaria was rife  plus particulates from rubbish burning and smoke from nearby housing overwhelmed any benefits the stoves could offer.

This doesn't mean that striving to make better stoves is invalid but rather that the whole environment needs consideration. It also doesn't make the current fashionable ranting about diesel and woodsmoke directly attributable to killing people right.

41 minutes ago, Martin du Preez said:

ok so surely the contribution from burning wood is to have come from biomass stations? and where did you get that figure from in the first place? also no ones sitting with their face over the chimney, there would never be a enough of a concentration of wood smoke in say teh countryside where most people have them, to have any significant affect on health

 

Are you referring to something I posted?

30 minutes ago, richardwale said:

Hi, what’s an ad plant?

Anaerobic digestion plant I guess, mix a load of food waste , silage and cow slurry up, heat it to blood temperature and the microbes give off methane and carbon dioxide from respiring the volatile solids in it. Methane and CO2 fuel a genset which supplies electricity to the grid and use some of the heat from the engine to keep the digester warm, the rest is available for other uses.

2 minutes ago, SteveA said:

Yep, there's that plus the exit (eg, chimney pot) temperature is much lower so far more of the heat is absorbed into the mass (when compared with a typical wood burning stove).

 

Yes I heard that and although they were talking in Fahrenheit  I'd have to sit down and work the partial pressures of all the flue gas constituents to actually see if one could get that low (140F was mentioned which is only 60C) without water running back into your stove.

In practice the 350F =~170 C which they mention as being a test standard for stoves is far more realistic  for a flue exit temperature into a 2 storey chimney in order to avoid condensation in the chimney. If I change from the 100C figure I used to 170C the stove efficiency drops to 85%. It gets worse if you allow that the air actually comes from outside, as do the logs which may be at 0C.

Just now, Woodworks said:

I had it in my head that it was from measuring a chemical analysis of the gases to determine how complete the combustion was but in the thread on Navitron Ivan said  " The efficiency is calculated from energy content of fuel vs ratio of heat lost up the chimney vs heat lost from the stove. I'm not sure of the exact calculation, but it's a standard controlled test procedure." 

 

 

 

You only need a complete ultimate flue gas analysis if some of the chemical energy is being dumped unburned up the flue, this is typically the case when smouldering damp wood. In a clean burn we can assume complete oxidation so all the chemical energy is release in the stove. Then the only heat loss from the system is what goos up the flue. This has two parts, the physical heat which is the specific heat of the mixture of gases times the difference between flue temperature and room temperature plus the latent heat of vaporisation of all the steam that goes as part of the flue gases.

16 hours ago, Woodworks said:

I read something about how testing was done from a guy involved in the development of the Burley. The percentage figure is derived from measuring of the flew gases and the efficiency of conversion but nothing to do with how much heat ends up in the room. 

 

Edit. Did a search for where I read this but looks like I was talking tosh haha https://www.navitron.org.uk/forum/index.php/topic,10364.0.html

What makes you think it was tosh?

32 minutes ago, SteveA said:

It's accurate according to whatever method they use to calculate to get to that figure.... but in the real world there is a huge loss of the heat in a woodburning stove that goes up and out the chimney & very little mass to absorb heat from the actual stove itself.

 

If you start with a closed warm room  with a stove in it and a flue plus a means to replace air that is used in the stove then law of conservation of energy applies.

Say you burn 1.25kg of wood at 20% moisture content and have to use 100% excess air to do so cleanly. If we define cleanly as no visible smoke and 30ppm CO then we can assume chemical energy losses to be around zero. Also ignoring ash content of the original mass.

Then  the energy content of the wood higher heating value is about 21MJ/kg. To burn this wood the rounded equation is something like this:

(C5H7O3+1.45H2O)+11O2+44N2 =>5CO2+4.95H20+5.5O2+44N2

where the bit between brackets is the surrogate formula for wood at 20%mc wwb

The N2 is inevitable as it is about 79% of air so you have to have it to get the oxygen you need.

To burn the 1kg mass of wood with 20% moisture  to extract 21MJ of heat you need to exhaust 8.8kg of flue gas and that includes 0.775kg of steam which you don't want to condense in your flue.To guarantee it won't condense it can be slightly lest than 100C but that's another story, we'll say it leaves the stove flue at 100C.

We have heated up all this mass from room temperature to exhaust it at 100C that means we have raised the exhaust gases from about 20C to 100C, lets assume the same specific heat as  of air about 0.001MJ/kg. Therefore our losses up the flue are the difference in heat in the flue from the original air and wood input plus the losses in converting the hydrogen in the input to steam, this equals ~2.5MJ out of our  original 21MJ HHV and so the maximum stove heat efficiency into the room is 88%

Where a mass heater scores is it releases the heat from the wood as above in a short hot burn  but then no further mass flow occurs up the flue so there are next to no losses from a stove "ticking over" all the rest of the day.

On 02/05/2018 at 23:23, openspaceman said:

 

No that's why tippers are ubiquitous

That sounds like a challenge, I've only done it with a smaller amount in a pug 504 pick up but will try to see if the boss lets me lay a tarp on the canter floor on the next job he's booked me for, May 24th.

Unfortunately I have been cancelled for this job as the boss's truck exhaust fell off and it will now be done without my assistance next week, I had the plastic woven sheet and rope in the car ready to try but will have to find another way to demonstrate the principle.

That's Three jobs this week I've had cancelled

1) because the Dipso lady with the overgrown garden I recovered last season can't cope with visitors so the bramble growth will take over all the lawn.

2) the canter I arranged to borrow to move some logs didn't come back from repairers in time and now is back on roofing work

3) Boss's truck exhaust problem

It makes retirement even more relaxing than I intended

8 hours ago, Richard 1234 said:

We got an email from school instructing us to switch our engines off no matter how many seconds we waited at school drop off/pick up time!

Which is much as I was expecting would start happening

1 hour ago, Martin du Preez said:

 No I'm sorry stoves are efficient if used properly.

Yes

1 hour ago, Martin du Preez said:

 

Wood smoke isn't going to kill anyone,

Well components of it have definitely got the potential to cause or aggravate a condition which will shorten a life

1 hour ago, Martin du Preez said:

 

it's been happening for centuries

Yes and so have cancers associated with it, Polycyclic Aromatic Hydrocarbons arising from poor combustion of coal or biomass (including cigarettes) have been shown to have causal links to lung and scrotal cancer and implicated in ischemic heart disease and chronic obstructive pulmonary disease

1 hour ago, Martin du Preez said:

 

 They are insignificant compared to other sources of pollution.

Have you a cite for that? Recent publications suggest over 30% of particulates are a result of combustion of wood, what is missing is that they are probably not contributed from modern stoves correctly burning dry wood.

28 minutes ago, Stere said:

If on mains gas for the majority of people why do you need to burn wood apart from the stove look pretty or be trendy.

 

 

I can see a few reasons:

1) we are burning gas at an alarming rate and it was intended that building regs would deprecate gas connections for new builds by 2016, what the current situation is I don't know.

2) Most of us on this forum burn wood because it heats our homes cheaper than other fuels. Granted this is not true for most who buy logs as a luxury item. Since the demise of the pulp mills wood burning has provided an economic outlet for forestry.

3) It is possible and practicable to burn wood acceptably cleanly

1 hour ago, swinny said:

Can i get a bigger and stronger tipper pump/ reservoir to replace it then? Its poor!

First step, after making sure the electrical connections are making good contact, would be to check the pressure the pump reaches and whether the pressure relief valve is opening too early. Getting a new pump and reservoir is easy enough but you're limited by how much current you can provide at 12 Volts

1 minute ago, Stumpy Grinder said:

Wood burners are insignificant compared to the real sources of pollution?

Is that a question or rhetoric?

You cite a couple of accidental sources which no one can have control over whereas there are a number of ways planned and regular woodburning could be controlled, though for now I think it will only be new installs that are affected and maybe larger producers of firewood (who already are likely to have a vested interest in sales of kiln dried wood).

How many of us still remember the plumes of smoke rising from cereal fields in July-August prior to 1993?

34 minutes ago, Matthew Storrs said:

Probably more particulates released by a large bonfire in one go than wood burners burning nice dry logs.

Piece of string but in general yes because the excess air cools the flame, which is why a bonfire always has a plume of blue smoke even when burning well.

When I started even in our affluent bit of the country bonfires were the norm, ten years later chippers began to appear and by 1990 they were ubiquitous. Now most home owners wouldn't entertain the idea of allowing one to burn on site yet, subject to amounts and not creating dark smoke it remains legal.

In much the same way cigarette smoking in buildings first became frowned upon and then banned I wonder if a diesel chipper left on high idle will start attracting comments.

9 hours ago, Big J said:

It's quite funny that they are considering these measures to penalise small scale firewood users, whilst at the same time paying hundreds of millions out in RHI payments for larger organisations to burn timber products that are almost never under 20% MC. Seems ludicrous to me.

That's because you consider wood at 20% moisture content being the only way to burn cleanly. In fact if you keep the combustion temperature up  and allow the flame to burn out without quenching then you can burn greener wood cleanly. The  advantage large scale burners have is that the combustion can take place well before any heat is lost from the flame and before flue gases reach a heat echanger. On a smaller device the stove walls are often the only heat exchange surfaces, when they are only metal boxes the flame has little chance to complete its burn before it comes into contact with a col metal surface. This is why more recent designs have firebricks to increase firebox temperature and often pre heated air but the small size alone means heat losses per firebox volume are higher than large devices.

So as one of the larger heat losses in a fire is from vaporising water it makes sense to minimise this loss to keep combustion temperatures up, hence the requirement for 20% mc wood.

I don't know what other techniques will be necessary to meet the new ecodesign standards but it looks like HETAS will only be allowed to sign off these ecodesign stoves so simple stoves will no longer meet building regulations let alone the old DEFRA exempt stove category.

1 hour ago, dig-dug-dan said:

My  current scattolinni tipper has a multi stage ram, and the guy who came out to convert it to three way said they have maximum power at start, but by the time it gets to the top, its reduced.

So in essence, there is a way of adjusting it, but i dont know how!

I doubt it's adjustable, the engineer also probably got his terminology wrong and should have said force rather than power.

With a multistage ram the piston area of the first stage is highest, so as force equals pressure times area there is more force produced by the first stage than latter stages, with necessarily have smaller pistons and areas.

7 minutes ago, Graham said:

Think you might have the answer there.  It works a lot better with a quick push on the pedal.  I'll see if I can get hold of seals.  Thanks.

It may be easier to replace the lot

https://www.ks-international.com/isuzu-4x4-and-truck-parts/isuzu-4x4-parts/isuzu-pick-up-parts/isuzu-d-max-tfs86-2-5td-2006-05-2012/clutch.html

2 hours ago, Graham said:

Wondered if anyone may clues regarding a clutch issue.  Isuzu pickup 09 2.5.

 

The other day the clutch pedal had a 'different' feel to it.  Sometimes it behaves normally; sometimes won't disengage fully at standstill and becomes difficult to engage first or reverse and if you depress it again it goes into gear.  As soon as your moving it seems ok.

 

There are no leaks from either cylinders and fluid level is good.  No noise from the clutch to indicate anything amiss.  Anything else I could check apart from getting someone to drop clutch out?

Possibly worn master cylinder seals. This won't show a leak as the fluid returns to the reservoir. Symptoms include the clutch gradually engaging when in gear and the pedal down. Also a vigorous stamp  operates the clutch but a gentle push doesn't