So, you're looking to maximise efficiency eh.... Step 1 - remove all extra pumps. Step 2 - remove all unnecessary hydraulic separation. Step 3 - ensure optimum flow rate at all times by removing mag filter, fill-flush-flowsetters and the like. Step 4 - disable all external thermostats and dial in your weather comp curve.

Silly question, perhaps, but do you have a problem with the noise of the unit? If so, are you able to quantify it? Not necessarily in terms of decibels but some kind of description that can allow us to understand the scale.

I have an Ecodan (a PUZ-WM85VAA) that is installed about that distance from a side wall of our house and the pipework runs straight to the wall, up the wall and then into the loft (all well insulated, I might add). Directly the other side of the wall is the head board to my and my wife's bed, so we would certainly know if the Ecodan was being noisy, but it's quiet as a mouse, to the extent that our neighbours have commented on how much quieter it is than they expected. In short, there's no reason why an Ecodan can't be installed to run quietly.

All this adds up to the suggestion that any noise issues you may be having could be related to the rest of the system, not the ASHP. As @hughf suggests, taking a look at pumps, flow rates and so on may well be a good start.

Thanks @majordennisbloodnok and @hughf ffor your replies.

Reflecting on my post, I wanted validation that the external parts of my install were optimal, and if not, what would be optimal.  The 'trigger' for the post was, yes, probably majority due to the noise, though also to ensure performance (and, likely ultimately, reliability/failure) and efficiency (not spending more money than required by the unit overworking e.g. due to reduced flow rates, poor insulation, etc).

HughF's suggestions are welcomed and I will look at the elements inside the house once I know outside is as good as I can get it.

Posted by: @majordennisbloodnok

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Silly question, perhaps, but do you have a problem with the noise of the unit? [snip]

Yes, there is humming/vibration throughout the house and can hear the unit ramp up + down indoors at the opposite side to the pump!

I have an Ecodan (a PUZ-WM85VAA) that is installed about that distance from a side wall of our house and the pipework runs straight to the wall, up the wall and then into the loft (all well insulated, I might add).

It sounds like you have a nice straight run from the flexihoses up to an elbow straight into the house - this takes me back to the question of optimal (minimum) pipe run and whether bends (at the short run we have) negatively impact, which I'd like opinions/facts on.

(How) is your pipework secured to the brickwork / how does your external install compare with that noted from para 2 in https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/ashp-flow-through-pipes-is-noisy-and-preventing-us-from-using-at-night-looking-for-help/paged/2#post-25615 (which I'm working through at present, though it feels the pipework-through-brick elements may be at least part of the issue)?

@iancalderbank, noting the above and your comments in the post I linked to in which you touch on some of the elements in my OP, may I please ask - is there a 'definitive minimum' install standard that one could refer to when speaking with installers?  You mentioned MCS inspection - do you know if Mitsubishi would insist on installs passing this, or another/equivalent (and if so, which), certification before they would consider servicing/supporting it?  For example, *must* primary pipes going through brickwork have the insulation type you mention or is it just 'best practice'?  Any related info gratefully received.

(Also, happy to remove and repost this in the other thread if more-appropriate)

@rhh2348 not that I've been ever involved but from what others have said, getting MCS to actually rectify is a waste of time. So its more about best practice, and if you can improve it yourself, do so.

post some photos?

is your efficiency issue due actually insulation or something else? more normally when people have efficiency issues its a system design thing. have you thought about flow temps, weather comp, do you have low loss headers / buffer tank, all that stuff. plenty of threads on this, several focused on ecodan.

(I can't seem to edit my original post so commenting here).

The post was intended to discuss optimising efficiency, performance, and quietness of all the *external* parts of the system, so I could work backwards / move onto the internal elements from there.  @iancalderbank covered off some of the elements around primary pipework routing and insulation in the post I linked to (thanks again Ian).

I've now split out creating an optimal base into a separate topic but am still keen to hear opinions around the other elements of an external install to achieve an optimal, Mitsubishi-approved setup if people would be generous enough to offer their thoughts.

@rhh2348 ok get it, you want to focus on the external. I do think it would help if you post some photos. picture paints a thousand words and all that.

Hi - as Ian said it really would be a great help if you could post some photos of your installation.  

In the meantime, noisewise, somehing you maybe could have a look at is whether your 6kW Ecodan has enough spare capacity to operate comfortably in one of the Quiet Mode settings.  If your controller is FTC6 the option should be available under Heat Pump Settings in the Service menu.

I run our Ecodan in Quiet Mode all year, except during continuous periods at sub zero ambient when I switch over to Normal mode.

Quiet Mode limits maximum compressor speed.  On our 11.2kW it is considerably quieter.

Just for comparison, ours is freestanding on the antivibration pads, standing on stone paving.  This means it can be lifted (shuffled) out on the flexible connections sufficiently for rear cleaning if needed.  Your 6kW should be considerably lighter.

Posted by: @skd

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In the meantime, noisewise, somehing you maybe could have a look at is whether your 6kW Ecodan has enough spare capacity to operate comfortably in one of the Quiet Mode settings.  If your controller is FTC6 the option should be available under Heat Pump Settings in the Service menu.

Yes, I did try that a few weeks ago and it did seem to make a difference, though that might have been placebo effect if I misunderstood the Quiet Level setting (see another of your posts and my follow-up)!

What differences, if any, did you notice between the three settings / which one are you on now?

Also, I started tweaking my W/C curve yesterday - it was mild last night however the unit was barely audible with my first W/C attempt, which is promising (as HughF alluded to).

Just for comparison, ours is freestanding on the antivibration pads, standing on stone paving.

Thank you - do you have a link to the pads you used / are you happy with that setup/would you do it again?

Posted by: @rhh2348

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Posted by: @skd

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In the meantime, noisewise, somehing you maybe could have a look at is whether your 6kW Ecodan has enough spare capacity to operate comfortably in one of the Quiet Mode settings.  If your controller is FTC6 the option should be available under Heat Pump Settings in the Service menu.

Yes, I did try that a few weeks ago and it did seem to make a difference, though that might have been placebo effect if I misunderstood the Quiet Level setting (see another of your posts and my follow-up)!

What differences, if any, did you notice between the three settings / which one are you on now?

 

Also, I started tweaking my W/C curve yesterday - it was mild last night however the unit was barely audible with my first W/C attempt, which is promising (as HughF alluded to).

 

Just for comparison, ours is freestanding on the antivibration pads, standing on stone paving.

Thank you - do you have a link to the pads you used / are you happy with that setup/would you do it again?

 

2 black bars (Level 1 QM) also reduces noise, but to a lesser degree.

The pads were ordered by the installer, and are described as Mitsubishi anti vibration feet 600mm.  They seem well made, durable and effective, so I wouldn't hesitate to use them again.

Ours is the 11.2kW R32 Ecodan.  Dimensionally the enclosure appears to be the same as the 6kW version.

The most important thing to remember with external insulation is that it’s UV stable. So that’s either primary pro, or aluminum covered rockwool.

standard insulation isn’t UV stable and will degrade over time.

I have primary pro through the wall, where I then transfer over to regular climaflex grey stuff. Flow and return are lagged all the way to the cylinder.