Beware: Smokey and the Log Burning Bandits

[dpmiller]

a defrost cycle (on our ASHP anyway) is less than ten minutes every hour or so. Plus defrosts occur most often when the temperature is above freezing, so some of that efficiency loss diminishes when it's *really* cold. If stopping heating for a few minutes every hour makes a house impossible to heat then there's something else going wrong there...

[Kelvin]

34 minutes ago, Ecthelion said:

That’s excellent, must be a really good house.

 

i didn’t say that my ASHP had us at 17.5. More like 19 when we had 3 days below zero and nights at minus 10. But 19 is not acceptable to us, and the wood burner was used. All ASHPs frost cycle and if the weather is cold enough for long enough there is a limit to what they can do. 
 

The defrost cycle shouldn’t have much impact. These were taken on the same day. 
 

 

[Ecthelion]

21 minutes ago, dpmiller said:

a defrost cycle (on our ASHP anyway) is less than ten minutes every hour or so. Plus defrosts occur most often when the temperature is above freezing, so some of that efficiency loss diminishes when it's *really* cold. If stopping heating for a few minutes every hour makes a house impossible to heat then there's something else going wrong there...

10 minutes an hour with the heating off matters at low temps, and then it has to get back up to flow temp, so it’s not just 10 minutes per hour, it is more like 20, which is a third of the system’s capability. 

[Ecthelion]

5 minutes ago, Kelvin said:

The defrost cycle shouldn’t have much impact. These were taken on the same day. 
 

 

Very impressive. I’ve never seen known an ASHP to be capable of that. 

[Kelvin]

10 minutes ago, Ecthelion said:

10 minutes an hour with the heating off matters at low temps, and then it has to get back up to flow temp, so it’s not just 10 minutes per hour, it is more like 20, which is a third of the system’s capability. 

The important data point is your heat loss when the heating is off. It ought to be negligible over that time period. 

[ProDave]

We keep on having this WBS debate, it is a Marmite subject and nobody is going to convince the "other side" that they are wrong.

 

I have one because we have trees which properly managed produce wood so I burn it.  If I had to buy wood to burn, I would not bother.

 

But the WBS is a good second source of heat, even a passive house will loose it's temperature when it's well below 0 and the the power is off for several days because we are a low priority after a storm.

 

The over heating myth.  Yes if we crank the stove up full and shut the doors to the room it is in (largest room in the house) it would quickly get very hot in there, but leave all the downstairs doors open and the heat can get to all the house without overheating any one room.  Perhaps that is down to design that we wanted double doors to the main downstairs rooms to open it all up when we want to.

 

I will start to give the environmental arguments against a WBS just a little credence when there is a public admission that burning wood in DRAX on an industrial scale was a bad idea and should never have been done  and it has been closed with immediate effect.  In the mean time some of the electrons powering my ASHP may well have come from there.

[Ecthelion]

18 minutes ago, Kelvin said:

The important data point is your heat loss when the heating is off. It ought to be negligible over that time period. 

Not at -10.

[SteamyTea]

1 minute ago, ProDave said:

We keep on having this WBS debate, it is a Marmite subject and nobody is going to convince the "other side" that they are wrong.

Does that mean you do not believe the science behind the debate?

 

2 minutes ago, ProDave said:

I will start to give the environmental arguments against a WBS just a little credence when there is a public admission that burning wood in DRAX on an industrial scale was a bad idea and should never have been done  and it has been closed with immediate effect.

Isn't that like saying it is OK to steal from a shop because you heard that someone else had done it.

[SteamyTea]

@Ecthelion

 

Have you got UFH and if so, what is the U-Value of it under the pipework?

[Ecthelion]

4 minutes ago, ProDave said:

We keep on having this WBS debate, it is a Marmite subject and nobody is going to convince the "other side" that they are wrong.

 

I have one because we have trees which properly managed produce wood so I burn it.  If I had to buy wood to burn, I would not bother.

 

But the WBS is a good second source of heat, even a passive house will loose it's temperature when it's well below 0 and the the power is off for several days because we are a low priority after a storm.

 

The over heating myth.  Yes if we crank the stove up full and shut the doors to the room it is in (largest room in the house) it would quickly get very hot in there, but leave all the downstairs doors open and the heat can get to all the house without overheating any one room.  Perhaps that is down to design that we wanted double doors to the main downstairs rooms to open it all up when we want to.

 

I will start to give the environmental arguments against a WBS just a little credence when there is a public admission that burning wood in DRAX on an industrial scale was a bad idea and should never have been done  and it has been closed with immediate effect.  In the mean time some of the electrons powering my ASHP may well have come from there.

We have a similar arrangement with down stairs. 3 sets of double doors. And the heat output of the stove is itself adjustable. 
 

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.

[Ecthelion]

1 minute ago, SteamyTea said:

@Ecthelion

 

Have you got UFH and if so, what is the U-Value of it under the pipework?

Yes I do. I don’t know, I would need to dig that info out.

[Ecthelion]

3 minutes ago, SteamyTea said:

Does that mean you do not believe the science behind the debate?

 

Isn't that like saying it is OK to steal from a shop because you heard that someone else had done it.

Only a few years ago the same people saying wood burners were great. No, I don’t believe the “science” personally. 
 

ancient poorly fitted wood burners are obviously not going to have the same consideration as modern state of the art burners, well installed. And I don’t believe the claims that started this discussion that wood burners account for more emissions than transport and industry. That’s just nonsense; nobody should take that at face value, surely?

[SteamyTea]

1 minute ago, Ecthelion said:

Yes I do. I don’t know, I would need to dig that info out.

Might be worth doing as you may just be heating the ground below your house up a bit too much.

 

2 minutes 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.

Do you accept the science behind it though, particularly the particulate problem?

[Ecthelion]

We also have our flue acting as a radiator, heating the upstairs where it goes through the hall. It is behind some louvred panels.

[Ecthelion]

Just now, SteamyTea said:

Might be worth doing as you may just be heating the ground below your house up a bit too much.

 

Do you accept the science behind it though, particularly the particulate problem?

It’s a suspended timber floor. 
 

no, I don’t accept that science. 

[SteamyTea]

Just now, Ecthelion said:

Only a few years ago the same people saying wood burners were great

Not all of them, I was writing about them 20 years ago, but more on the CO₂ neutrality argument.

[SteamyTea]

4 minutes ago, Ecthelion said:

We also have our flue acting as a radiator, heating the upstairs where it goes through the hall. It is behind some louvred panels.

Was the flu designed to account for this?

Over cooling flu gasses can cause problems.

[Ecthelion]

1 minute ago, SteamyTea said:

Was the flu designed to account for this?

Over cooling flu gasses can cause problems.

Of course it was.

[Kelvin]

20 minutes ago, Ecthelion said:

Not at -10.

My question was what is your heat loss. Do you know? -10 is relatively rare, certainly where I am in Perthshire and when it does get that cold it doesn’t stay that cold for long. A better argument for them is for power cuts as we get a few of those. So the worse case scenario is a lengthy power cut on the coldest week of the year. 
 

On the overheating ‘myth’. We spoke with two people who had built houses in the last couple of years to a reasonable standard. Both fitted stoves. Both said they never used them as it overheated the room they were in even with the internal doors open. They only used them at Christmas for the ambience. It was this that finally convinced my wife not to fit one. 

[Ecthelion]

4 minutes ago, Kelvin said:

My question was what is your heat loss. Do you know? -10 is relatively rare, certainly where I am in Perthshire and when it does get that cold it doesn’t stay that cold for long. A better argument for them is for power cuts as we get a few of those. So the worse case scenario is a lengthy power cut on the coldest week of the year. 
 

On the overheating ‘myth’. We spoke with two people who had built houses in the last couple of years to a reasonable standard. Both fitted stoves. Both said they never used them as it overheated the room they were in even with the internal doors open. They only used them at Christmas for the ambience. It was this that finally convinced my wife not to fit one. 

9.2 KW.

 

we do also get power cuts. 3 or 4 a year. Not often longer than a day. And yes, -10 is rare, probably 3 or 4 nights a year.

[Ecthelion]

5 minutes ago, Kelvin said:

My question was what is your heat loss. Do you know? -10 is relatively rare, certainly where I am in Perthshire and when it does get that cold it doesn’t stay that cold for long. A better argument for them is for power cuts as we get a few of those. So the worse case scenario is a lengthy power cut on the coldest week of the year. 
 

On the overheating ‘myth’. We spoke with two people who had built houses in the last couple of years to a reasonable standard. Both fitted stoves. Both said they never used them as it overheated the room they were in even with the internal doors open. They only used them at Christmas for the ambience. It was this that finally convinced my wife not to fit one. 

They maybe don’t know how to use them properly as the heat output is adjustable. 

[SteamyTea]

18 minutes ago, Ecthelion said:

9.2 KW

What is the performance curve of your heat pump.

It may only be delivering half of that at -10.

 

And just a point about science convention, it is kW, not KW, that would be kelvin multiplied by power.

Edited April 21 by SteamyTea

[JohnMo]

57 minutes ago, Ecthelion said:

Not at -10.

Mine was fine also, perhaps you need to adjust your Weather Compensation curve at the far end to compensate for defrosts, to bring the average temperature up to where it needs to be.

 

Or you are trying to run for too short a period of time.

 

Or system volume is not adequate and needs more volume adding for the defrost cycle to draw off. A volumiser on the return line of your heating system (not cylinder) would cool just the volumiser water not the radiator water.

[Ecthelion]

9 minutes ago, SteamyTea said:

What is the performance curve of your heat pump.

It may only be delivering half of that at -10.

 

And just a point about science convention, it is kW, not KW, that would be kelvin multiplied by power.

Yes I know, I just couldn’t be bothered to correct it. 
 

Do you mean the weather comp curve  parameters? Pretty sure those are ok. It’s set to flow 50 degrees at 0.

[Ecthelion]

1 minute ago, JohnMo said:

Mine was fine also, perhaps you need to adjust your Weather Compensation curve at the far end to compensate for defrosts, to bring the average temperature up to where it needs to be.

 

Or you are trying to run for too short a period of time.

 

Or system volume is not adequate and needs more volume adding for the defrost cycle to draw off. A volumiser on the return line of your heating system (not cylinder) would cool just the volumiser water not the radiator water.

I do actually think it should have a volumiser retrofitted and I’m in discussions with Grant for making sure that’s done before next winter. 
 

I challenged them about the failure to reach 21 in very low temps. It’s supposed to deliver 22 at -5.4 degrees outside but it doesn’t. I found in their paperwork that it should have either a LLH or a volumiser, but my install seemingly doesn’t and their grade 1 installer had deemed it not needed due to the heat loss calculations and type of property.