Posted by: @editor

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Having lived and visited various hot climates, I've found AC units to be significantly louder than air source heat pumps. Despite observing numerous heat pumps and reviewing several videos, it's hard for me to envision them causing disruption in a street, neighbourhood or community.

I have requested people that have complained about the noise of heat pumps to send me videos with dB readings, but am yet to receive a single video.

While I acknowledge some units may be noisier than others, our own heat pump—quite a beastly model—wouldn't disturb our sleep even if it were placed near our bedroom. Our decision to "hide" it was purely for aesthetic reasons, a topic for another discussion.

Compared to the intrusive noise from road and motorbike traffic, the gentle hum of our heat pump's fans seems almost negligible.

Videos do not capture the hum or vibration noise well at all - Some video cameras/phones even actively cut it out because of noise cancellation. As for the dB(A) measurements, we are back to the idea that 1dB(A) of one sound is as disturbing as 1 dB(A) of another. And the dB(A) measure cuts out a chunk of the dB raising elements of heat pump noise because of the A weighting.
This is why the last paragraph of the Welsh Govt report is spot on - the issue of heat pump noise is not understood well at all and the proper research has not been carried out.

The tonality issue is fundamental. And those who own heat pump are fat less bothered about the noise than neighbours who suffer the noise. I don't mind my clanking radiators, but I do mind yours coming through my wall (or rather a buzz emerging across my home).

It is an issue that could risk a successful rollout, and is well acknowledged in various reports. Sure HP tech is slowly improving but warehouses are still filled with models capable of nuisance. 

Posted by: @persephone

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4- My neighbour then appealed, and the LRB imposed the 'condition' which we are talking about. And I have no idea what this 'condition' refers to. 

If anyone understands the 'condition', I really appreciate it if they could explain it.   

OK

The actual text of the condition was:

Within six weeks of the decision being issued, an ‘at-source’ noise survey at the Air Source Heat Pump shall be undertaken and submitted to Fife Council for approval to demonstrate compliance with the predicted sound pressure levels at this source and the predicted sound pressure levels 1m from the first-floor façade of the adjacent residential property to the west. Alternatively, if these levels are exceeded, suitable mitigation shall be agreed in writing and thereafter installed with noise levels re-tested to demonstrate compliance with this or suitable alternative noise levels agreed by Public Protection.  Thereafter, the development shall be carried out in accordance with these approved details unless otherwise agreed in writing with Planning Authority in consultation with Protective Services.

So the question is what does the term 'predicted sound pressure levels' mean?

I cant actually persuade the applicants appeal statement to download at present, which is where I would expect the original definition of 'predicted sound pressure levels' will be found.  However....

Here is the comment made by Fife Council EHO about the appeal (interestingly this apparently reverses their previous position).  Note the reference to NR25/NR30 and to the applicants appeal statement

Note further the text from the FPRB conclusion and again the reference to NR25 and NR30

3.8       The FPRB then turned to the assessment of noise standards and, in particular, whether the Council’s noise requirements could be met.  They noted the concerns from the objector about various flaws in the appellant’s assessment of this issue.  In this regard, the FPRB then acknowledged requirements form the Council’s Public Protection team for noise generating proposals.  Specifically, that such proposals required to achieve compliance with an industry standard called the ‘Noise Rating’ standard (NR 25 and NR30) within any nearby residential properties, with lower (quieter) ratings requiring in bedrooms during the nigh time period.  In this regard, the FPRB considered extensive concerns raised by the objector regarding the predicted noise assessment undertaken by the appellant in considering whether the NR 25 and NR30 requirements had been met.  They also noted the WSP report, which suggested potential compliance, and an updated consultation response from the Public Protection team which was received via a standard consultation on the LRB case.  Updating their position from their previous response, the Public Protection team advised that the proposal could accord with the Council’s noise requirements (NR 25 and NR30) and therefore could comply with the noise condition on the previous planning permission.  Accordingly, after considering this issue and noting the comments from the Public Protection team regarding potential compliance with the above requirements, the FPRB resolved that the proposal would not result in unacceptable noise impacts to the nearby residents, including the property to the west, subject to a condition requiring compliance with the NR25 and NR30 noise standards on any issued planning permission.  As such, the FPRB reversed the decision of the Appointed Officer on this matter.  They therefore concluded that the proposal would comply with NPF4 Policy 14 (Design, Quality and Place) and Policy 16 (Quality Homes), FIFEplan Policies 1 (Development Principles) and 10 (Amenity) and the aforementioned guidance on noise with respect solely to potential impact on residential amenity.

and here is the extract from the consultants report.  Note the reference to NR25 again

"Sound level measurements of the ASHP installed at the rear of 41 Learmonth Place have been carried out
in proximity to it, to verify sound level predictions reported in previous correspondence and demonstrate
compliance with FC criteria. It was also possible to obtain a sound level measurement inside the master
bedroom of the applicant’s house, which is screened from the ASHP by a similar amount as the nearest
noise sensitive receptor.
The sound levels measured in proximity to the source are similar to those predicted using the methods
previously reported.
The sound level measured inside the bedroom with the windows open was NR 23, which is compliant with
the planning condition requirement of NR 25. Subjectively, the ASHP was just audible in the bedroom when
listening attentively. The assessor would not have found the ASHP sound to be objectionable. Extraneous
noise sources included birdsong and distant vehicles. It was not possible to reduce the influence of these
sources on the internal measurement, so the cited level really comprises an overly precautious estimate of
sound from the ASHP.
Based on the precautionary internal estimate of NR 23 inside the applicants home, NR 19 would be
expected in the bedroom of 39 Learmonth Place (under comparable open-window conditions), due to the
differences in distance attenuation between the façades of the two properties.
The information presented in this memo verifies the sound level predictions previously undertaken, and
also demonstrates that sound from the ASHP will meet the planning condition’s NR 25 criterion when
measured in the nearest noise sensitive dwelling. It is therefore concluded that the requirements of the
planning condition have been fulfilled."

So its pretty clear that the condition refers to NR25 (bedrooms)/NR30 (other rooms).

The report states that NR23 was measured in the applicants home (nearer to the heat pump than yours), which is already good enough to meet the condition and includes other extraneous noised that could not be excluded.  Based on attenuation due to distance, the report infers NR 19 in the neighbouring property (yours) which is better than the condition by 6dB.

I hope that helps.  I will try tomorrow to download the applicants appeal statement but given that the above are all consistent I cant see its going to change the picture.  

Based on this its easy to see why the Council, whether correctly or not, would conclude that the condition had been met.

PS - I have now downloaded the applicant appeal statement and I think this is the email (c0ntained in the statement) which gives the predicted noise levels, confirming that the condition relates to NR25 (or arguably approximately NR 29-6=23, but either way is met according to the WSP measurements)

Posted by: @jamespa

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the condition relates to NR25

Here are my questions/problems:

1- Isn't NR a real/physical measurement? 

2- Isn't NR25 and NR30 something that should be met at my house, not theirs?

As far as I understand, the whole NR policy, in this case and as one of the planning conditions, is for the neighbouring properties. So, in order to prove compliance with NR policy, the assessor was supposed to measure the noise 'inside my bedroom' or inside 'any habitable room' of my house, not to 'predict' it. 

Thanks again for helping me to figure out what the assessment is about. 

Posted by: @jamespa

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arguably approximately NR 29-6=23,

According to the assessment (the last line of the image you shared of the Appeal Statement), the NR in my bedroom is 17 below NR25, ie NR8. Is such a thing possible at all????

Posted by: @jamespa

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So its pretty clear that the condition refers to NR25 (bedrooms)/NR30 (other rooms).

If the condition only refers to NR, then what is the MCS calculation on page 8 of WSP assessment? What are the SPL predicted and SPL measured on page 9 of the same document? 

Posted by: @persephone

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Posted by: @jamespa

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the condition relates to NR25

Here are my questions/problems:

1- Isn't NR a real/physical measurement? 

2- Isn't NR25 and NR30 something that should be met at my house, not theirs?

As far as I understand, the whole NR policy, in this case and as one of the planning conditions, is for the neighbouring properties. So, in order to prove compliance with NR policy, the assessor was supposed to measure the noise 'inside my bedroom' or inside 'any habitable room' of my house, not to 'predict' it. 

Thanks again for helping me to figure out what the assessment is about. 

 

According to the report a real physical measurement was made inside the applicants house and gave a reading of NR23, 2dB below that required (at your house) by the condition, which is significant since noise pressure decreases with distance.

Your house is  a further 4m away from the heat pump, and the authors of the report have therefore used the inverse square law to infer the value at your house. which they estimate at NR19, 6dB below the condition value (which is a large margin!).

The assessor has no right of entry into your house, thus what the assessor has done is an entirely reasonable thing to do (in fact the only reasonable way to do it) unless there is a very sound reason to suppose that the inference will lead to a material change in the outcome (which, with a 6dB margin and an adjustment only for distance, is very unlikely).  At this stage, given the margin, I think you would need to prove them wrong not the other way round.  

Posted by: @persephone

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the condition only refers to NR, then what is the MCS calculation on page 8 of WSP assessment? What are the SPL predicted and SPL measured on page 9 of the same document? 

Further background information I imagine.  If you want someone to go through explaining every facet of a rather long report, even though it is not material to your situation, then I think you would need to pay for that service.

The plain and simple fact is that the material information is, so far as I can see, as described above.  Everything else is largely irrelevant background information added in for context and to make the report look bigger, thus justifying the fee and demonstrating that the matter has been explored is some depth (ie due diligence has been done), albeit that the material outcome can be summarised in a sentence (as is often the case).

The only way I can see you could possibly contest the planning situation would be to have a professional report done with measurements in your house which proved that the condition was not in fact met.  However, given the expert evidence to the contrary, this would be a waste of your money unless you have a solid reason to believe that it isn't met.

How much can you actually hear the heat pump and in what circumstances?

@persephone I suspect that the figures are arrived at by measurement ‘at source’ and at one or more points on the property at which the machinery is installed. Using reference tables, extrapolated figures will be arrived at. By such means this enables the assessor to produce a report without having to ‘trespass’ on your property or even request admittance to take measurements. This is only surmise on my part but it may be done this way to avoid any confrontations and to safeguard the assessor. Regards, Toodles.

Posted by: @jamespa

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I think you would need to pay for that service.

I contacted RMP which is quite well-known for their research for ASHPs, but they refused to 'review' the assessment and to provide their 'professional judgment'. I contacted them several times and asked them if they would confirm the accuracy of the assessment, but they refused to confirm/reject the accuracy. I contacted IOA, but they say they do not have such a service (checking the accuracy of noise assessments) .   

Posted by: @persephone

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Posted by: @jamespa

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I think you would need to pay for that service.

I contacted RMP which is quite well-known for their research for ASHPs, but they refused to 'review' the assessment and to provide their 'professional judgment'. I contacted them several times and asked them if they would confirm the accuracy of the assessment, but they refused to confirm/reject the accuracy. I contacted IOA, but they say they do not have such a service (checking the accuracy of noise assessments) .   

If you want someone to measure at your property just ask someone to measure at your property, don't ask them to review another's work.  I'm sure you could get someone to do this.  I was quoted £350 for an overnight measurement to determine local background.  You need to get on with it though, your neighbour will presumably be switching off their heat pump for the summer soon, other than for DHW (which can be a good test because heat pumps generally have to work hard for the DHW cycle.

However, given the expert evidence to the contrary, this would be a waste of your money unless you have a solid reason to believe that the condition is not met and think you stand a reasonable chance of collecting the evidence to prove it.

How much can you actually hear the heat pump and in what circumstances?  Is it causing 'a substantial and unreasonable detriment to your enjoyment of the property or injurious to your health'.  If so it might be better just to  pursue a nuisance claim, as I fear that reversing a decision on a planning condition which was made based on expert evidence is going to prove tricky, even if you could prove that the condition is not in fact met on some occasions (which is the absolute best you can hope for, I think unless WSP are fraudsters, a circumstance for which there is no evidence of which I am aware).

Posted by: @jamespa

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So its pretty clear that the condition refers to NR25 (bedrooms)/NR30 (other rooms).

@jamespa, @toodles, @editor

I don't think the condition refers to NR because if this is the case, then condition 1 and condition 2 of the LRB Decision Notice would be the same!  Condition 1- Within six weeks ... an at-source noise survey ... Condition 2- The total noise from all plant, ... complies with NR25 ... 

Also, just for clarification, I have no intention of using this platform as a free consulting service. I only write here because (a) I think people might find my experience useful and (b) tens of people whom I contacted so far have either ignored my questions or tried to whitewash the issues. I am only trying to understand the 'criteria' based on which my local council approved the installation. The system, based on my experience, approves compliance of any odd installation with random criteria and random methodologies, then throws you in a vicious circle to prove otherwise. Again, that's why I say all the MCS policies are ridiculously useless.  

Posted by: @persephone

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Again, that's why I say all the MCS policies are ridiculously useless.  

Whilst some of us may agree with you for other reasons, your position has nothing to do with MCS. The noise condition, which the report says is met, was set by your local planning review board.  That's absolutely nothing to do with MCS.

Posted by: @persephone

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I don't think the condition refers to NR because if this is the case, then condition 1 and condition 2 of the LRB Decision Notice would be the same!  Condition 1- Within six weeks ... an at-source noise survey ... Condition 2- The total noise from all plant, ... complies with NR25 ... 

here is the condition

Posted by: @jamespa

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Within six weeks of the decision being issued, an ‘at-source’ noise survey at the Air Source Heat Pump shall be undertaken and submitted to Fife Council for approval to demonstrate compliance with the predicted sound pressure levels at this source and the predicted sound pressure levels 1m from the first-floor façade of the adjacent residential property to the west. Alternatively, if these levels are exceeded, suitable mitigation shall be agreed in writing and thereafter installed with noise levels re-tested to demonstrate compliance with this or suitable alternative noise levels agreed by Public Protection.  Thereafter, the development shall be carried out in accordance with these approved details unless otherwise agreed in writing with Planning Authority in consultation with Protective Services.

"and the predicted sound pressure levels 1m from the first-floor façade of the adjacent residential property to the west." clearly refers to NR25/30 (in practice NR25)

"compliance with the predicted sound pressure levels at this source" refers to another number which I cant be bothered to look for in the documentation because it is wholly irrelevant, given that the key part of the condition is "sound pressure levels 1m from the first-floor façade of the adjacent residential property to the west."

Im sorry but, so far as I can see, you are clutching at straws here.  I reiterate:

How much can you actually hear the heat pump and in what circumstances?  Is it causing 'a substantial and unreasonable detriment to your enjoyment of the property or injurious to your health'.  If so it might be better just to  pursue a nuisance claim, as I fear that reversing a decision on a planning condition which was made based on expert evidence is going to prove tricky, even if you could prove that the condition is not in fact met on some occasions (which is the absolute best you can hope for, I think unless WSP are fraudsters, a circumstance for which there is no evidence of which I am aware).

Posted by: @jamespa

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a planning condition which was made based on expert evidence

I want to understand the condition because I think it is biased and is written in such a way to help my neighbour provide a document for it. The wording of the condition is done by the Head of Planning Services, however, the LRB members who reversed the refusal of the application had absolutely no expertise in planning. Again, I only want to understand what the condition is and if the assessment proves that it has been met.