Beware: Smokey and the Log Burning Bandits

[SteamyTea]

5 minutes ago, Ecthelion said:

Do you mean the weather comp curve  parameters

No.

In the data about your heating pump there should be a chart that shows the power delivered for different OAT, it may also show flow temperatures and CoP.

 

Generally a LLH, volumiser or buffer is to reduce short cycling, it does not increase the power or flow temperature.

 

Starting to sound like you have an incorrectly specified system.

[JohnMo]

3 minutes ago, Ecthelion said:

their grade 1 installer had deemed it not needed due to the heat loss calculations and type of property. 

Requirements for a given volume of water (or volumiser) is nothing to do with heat loss or house type calculations, it's to do with heat pump minimum output and required minimum volume of water for defrosting.

[ProDave]

This thread is just showing how individual houses differ.

 

My 5kW heat pump copes with heating our house at +20 indoors and -10 outside.  -10 for a week or more is quite normal here in winter with high pressure and no wind to bring warmer air.  When you hear on the weather forecast "colder in some sheltered glens" that is us.  It rarely defrosts at -10, there is just too little moisture in the air by then.  A few degrees either side of 0 is when defrosting is more likely.  My LG heat pump seems incredably quick at it's defrost cycle, the compressor and fan stop.  You hear the 4 way  valve change over.  the compressor starts but not the fan.  When the evaporator warms up and melts the ice, only then does the fan start and blow away all the now melted ice in a puff of "steam".  Then the compressor and fan stop the 4 way valve changes back and normal operation resumes.  That takes about 2-3 minutes in total.

 

Another feature of our house is it will not heat up or cool down quickly.  Nothing to do with thermal mass but everything to do with low decrement delay insulation.  Perhaps that is why the WBS does not overheat our house but others have that problem?

[Ecthelion]

40 minutes ago, SteamyTea said:

No.

In the data about your heating pump there should be a chart that shows the power delivered for different OAT, it may also show flow temperatures and CoP.

 

Generally a LLH, volumiser or buffer is to reduce short cycling, it does not increase the power or flow temperature.

 

Starting to sound like you have an incorrectly specified system.

Not accordingly to Grant or the installer. Hard to see how you could reach that conclusion on the information provided.

[Ecthelion]

41 minutes ago, JohnMo said:

Requirements for a given volume of water (or volumiser) is nothing to do with heat loss or house type calculations, it's to do with heat pump minimum output and required minimum volume of water for defrosting.

I’ll need to say that to Grant.

[Ecthelion]

39 minutes ago, ProDave said:

This thread is just showing how individual houses differ.

 

My 5kW heat pump copes with heating our house at +20 indoors and -10 outside.  -10 for a week or more is quite normal here in winter with high pressure and no wind to bring warmer air.  When you hear on the weather forecast "colder in some sheltered glens" that is us.  It rarely defrosts at -10, there is just too little moisture in the air by then.  A few degrees either side of 0 is when defrosting is more likely.  My LG heat pump seems incredably quick at it's defrost cycle, the compressor and fan stop.  You hear the 4 way  valve change over.  the compressor starts but not the fan.  When the evaporator warms up and melts the ice, only then does the fan start and blow away all the now melted ice in a puff of "steam".  Then the compressor and fan stop the 4 way valve changes back and normal operation resumes.  That takes about 2-3 minutes in total.

 

Another feature of our house is it will not heat up or cool down quickly.  Nothing to do with thermal mass but everything to do with low decrement delay insulation.  Perhaps that is why the WBS does not overheat our house but others have that problem?

Indeed. Possibly we just had a very damp cold spell.

[JohnMo]

16 minutes ago, Ecthelion said:

I’ll need to say that to Grant.

From the grant install manual 

 

 

 

[SteamyTea]

23 minutes ago, Ecthelion said:

Hard to see how you could reach that conclusion on the information provided.

Because I know the thermodynamics.

 

 

[Ecthelion]

1 hour ago, JohnMo said:

From the grant install manual 

 

 

 

Interesting, thank you. The difference I get tends to me about 5 degrees. I wonder if mine is at level 2 or 1. After a frost cycle in very cold temps, I find the flow temp struggles to get back up and will just about hit 40 before the frost cycle kicks in again and it has to start again. 

[Ecthelion]

2 hours ago, JohnMo said:

From the grant install manual 

 

 

 

I’ll have a look into this in the morning. Thank you.

 

 

[Ecthelion]

I got in this morning and it was set to minimum and also frost protection set to off. I have set it to max and left frost protection as it was for now. 

[JohnMo]

7 minutes ago, Ecthelion said:

got in this morning and it was set to minimum and also frost protection set to off. I have set it to max

Did you set to get the difference between flow and return as they say or just increase the speed?

[Mr Blobby]

19 hours ago, Ecthelion said:

I don’t buy any environmental argument against modern wood burners. It’s more a case of an agenda towards heat pumps and a dislike of other people having nice things.

 

And then there is the actual science and the facts.

Particulate matter is very bad for you.  All that nasty pollution comes from wood burners.  You may not like the facts but that does not make them any less true.

 

 

[Ecthelion]

38 minutes ago, JohnMo said:

Did you set to get the difference between flow and return as they say or just increase the speed?

I switched dip switch 6 to off to take it from minimum to maximum. I think that increases the pump speed which would increase the volume? 
 

for the differential between flow and return, would that be a parameter setting or would additional volume make the difference? Normally it’s about 4 or 5 degrees but as you say should be higher.

[JohnMo]

Just now, Ecthelion said:

would increase the volume

No just velocity and volumetric flow rate of the water changes. Volume of water will remain exactly the same.

 

Flow rate changes (changing pump speed) moves differential temp between flow and return.  This in turn changes heating output, due to a change in mean flow temperature.

 

To decrease differential you increase flow.

 

To increase differential you decrease flow.

 

So if you normally have 5 to 6 difference between flow and return and you want 8 you would decrease pump speed.

[Ecthelion]

3 minutes ago, JohnMo said:

No just velocity and volumetric flow rate of the water changes. Volume of water will remain exactly the same.

 

Flow rate changes (changing pump speed) moves differential temp between flow and return.  This in turn changes heating output, due to a change in mean flow temperature.

 

To decrease differential you increase flow.

 

To increase differential you decrease flow.

 

So if you normally have 5 to 6 difference between flow and return and you want 8 you would decrease pump speed.

Thanks. I don’t think it’s possible to decrease pump speed. It was already on the lowest setting.

[Ecthelion]

27 minutes ago, Mr Blobby said:

 

And then there is the actual science and the facts.

Particulate matter is very bad for you.  All that nasty pollution comes from wood burners.  You may not like the facts but that does not make them any less true.

 

 

Clean burn technology in modern wood burners resolves the particulate issue. 
 

there should be grants for people to have old burners replaced, and a time limit.

[JohnMo]

15 minutes ago, Ecthelion said:

Clean burn technology in modern wood burners resolves the particulate issue. 
 

there should be grants for people to have old burners replaced, and a time limit.

 

Not sure about grants.

 

Short read

https://www.mdpi.com/2073-4433/11/12/1326

 

Another opinion

https://www.scan-stoves.com/this-is-scan/sustainable-heat/sustainable-wood-burning-heat-clean-burn-fireplace#:~:text=Enova (responsible for the net,as warmth for your house.

 

My Experience

Have a HETAS Scanline (nominal output is 4.7kW) is stated as particle emissions of 0.63 grams per kilogram of burnt wood. And emission levels of PM dust (at 13% oxygen) of < 3 mg / m³.

 

Overall emissions are below

 

Not quite resolved but reduced particulate matter. Interesting is the allowable limits and what my stove actually achieves.

 

Another source of information says this (below), which again can be misleading. For example it says Defra Exempt Ecodesign stove is up to 335g/MWh for particulate matter.  However using my example above, it is less it 13x less than the allowable PM emissions (less than 3 compared to an allowed equal to less than 40).

 

I do know that one or a max of 2 decent logs is all I need to heat the house and the burn time is several hours, once extinguished the soapstone carries on giving off low levels of heat for many hours. However we have have the fire on infrequently, we only use logs that are old and very dry. Most of the wood is from trees that were ready to fall down (dead or starting to rot in the centres) and taken down for safety reasons. Other site generated wood is, timber off cuts from the build, and trees removed because they were in the way.

[Mr Blobby]

1 hour ago, Ecthelion said:

Clean burn technology in modern wood burners resolves the particulate issue.

 

Well that's not really true though is it.  A bit like menthols or marlboro lights being less harmful so smoke as many as you like.

 

 

 

https://www.theguardian.com/environment/2022/feb/15/wood-burners-emit-more-particle-pollution-than-traffic-uk-data-shows

 

 

 

[JohnMo]

25 minutes ago, Mr Blobby said:

 

Well that's not really true though is it.  A bit like menthols or marlboro lights being less harmful so smoke as many as you like.

 

 

 

https://www.theguardian.com/environment/2022/feb/15/wood-burners-emit-more-particle-pollution-than-traffic-uk-data-shows

 

 

 

Well that is just rubbish in rubbish out.

 

The particle mass limit was significantly tightened going from Euro 5 to 6 for heavy duty vehicles, cut in half from

0.02 g/kWh to 0.1 g/kWh on steady-state testing, and from 0.03 g/kWh to 0.01 g/kWh on transient testing.

 

Again using my stove for direct comparison, its allowed 335g per MWh, or 0.335 per kWh (as o could be 3x worse that a HGV), but achieves 1/13 the allowable or 0.025g/kWh. So way lower than that allowed by a HGV in practice.

[dpmiller]

I *think* this is the latest EN for woodstoves? The useful specs are in this sample...

 

https://cdn.standards.iteh.ai/samples/70953/f80d67b8d4d14275aedda4c54d923175/SIST-EN-16510-2-3-2023.pdf

 

and the Bronpi I installed is designed in compliance. Next step is probably catalytic converts like the stoves in the US?

[SteamyTea]

1 hour ago, JohnMo said:

Have a HETAS Scanline (nominal output is 4.7kW) is stated as particle emissions of 0.63 grams per kilogram of burnt wood. And emission levels of PM dust (at 13% oxygen) of < 3 mg / m³.

 

1 hour ago, JohnMo said:

. For example it says Defra Exempt Ecodesign stove is up to 335g/MWh for particulate matter.  However using my example above, it is less it 13x less than the allowable PM emissions (less than 3 compared to an allowed equal to less than 40).

Tope one is emission per mass, the second one is emissions per unit energy.

Now I don't know of the second one is talking about primary or delivered energy.

In the first one, there is also a reference to <3mg/m³.  Pumping in extra air to the flu can trick that figure, it is similar to 'throttle hang' on a modern car.

[Ecthelion]

1 hour ago, Mr Blobby said:

 

Well that's not really true though is it.  A bit like menthols or marlboro lights being less harmful so smoke as many as you like.

 

 

 

https://www.theguardian.com/environment/2022/feb/15/wood-burners-emit-more-particle-pollution-than-traffic-uk-data-shows

 

 

 

But most people are not smoking as many as they like. Use is largely limited to a small portion of days in the year, and a small portion of those days. 
 

when clean burn technology and design is factored in, it is absolutely fine to use wood burners appropriately and in appropriate settings. 

[Mr Blobby]

11 minutes ago, SteamyTea said:

 

Tope one is emission per mass, the second one is emissions per unit energy.

Now I don't know of the second one is talking about primary or delivered energy.

In the first one, there is also a reference to <3mg/m³.  Pumping in extra air to the flu can trick that figure, it is similar to 'throttle hang' on a modern car.

 

The calorifc value of timber is required.  The official particulate number relies on efficiency greater than 65% at 4.7 kW. 

What are those smoke numbers like when the fire is first lit?  The smoke from my neighbours house is at its most obnoxoious when being lit, when efficiency will be poor and output very low.  I suspect these emissions, which will be in the many grams per kWh, have been excluded from the official data.

 

Edited April 22 by Mr Blobby

[JohnMo]

3 minutes ago, SteamyTea said:

 

Tope one is emission per mass, the second one is emissions per unit energy.

Now I don't know of the second one is talking about primary or delivered energy.

In the first one, there is also a reference to <3mg/m³.  Pumping in extra air to the flu can trick that figure, it is similar to 'throttle hang' on a modern car.

Basically all the units are rubbish, they should all be the same, they just pluck any old units out the air, pun intended.