I wish i could speak with more direct experience.
But regarding the tank location issue, could it be we can get away with smaller tanks and have our heat pump setting set to regularly reheat. That huge 200L tank for 1 family has always seemed strange to me, when noone even has a bath!
Especially with the smart tech available these days to manage it all.
I guess as everything heat pump and efficiency, it has to be set specifiic to each use case. This table comes to mind from Heat Geek
Just as the EPC supposedly reports energy usage for a typical family, so MCS specifies for the same non-existent family. Your requirements are unique to you and your home. You may find an installer who accepts that.
It looks like the Sound Power Level for your Daikin unit is 62dB LWA.
This compares to 57dB LWA for say the NIBE F2040-12kW unit.
So your unit is already on the noisy side.
A 5dB difference (noisier) will be fairly noticeable.
In our case we have the NIBE F2040-6kW unit which has noise spec of 50dB LWA, so 12dB lower than your Daikin. This is a lot lower.
If you looked at this in terms of stand-off distance then your 62dB LWA unit would give a similar sound level at 8m as ours would at 2m (all other things being equal).
Do you have an MMI that looks like this?
In the installer menu (password 5678) there is a portion for low noise setting. The low noise setting also improves COP as the system runs more gently, to reduce the noise.
Thanks @zapaman . Yes 62dB seems to be the level for the whole range. I wasted a fair bit of time trying to prove I needed a smaller ASHP to try to get this figure down until realising this. The focus was for permitted development reasons at the time and I had no personal reference point of what 62dB would be like.
I had incorrectly assumed that at worst this may be just a noticeable background noise and only for a couple of short periods a day however the cold weather proved me wrong and it can be at near this level for a considerable portion of the day. I am going to keep a record the next cold snap but it ‘feels’ like 40% of the day it is at this sound level when temps dip below 4c.
Assuming (and that’s not a fair assumption) a 12Kw NIBE F2040-12kW unit would be suffice for our house it sounds like it would be a better option.
What I don’t know is if an oversize ASHP could also contribute to the noise problem by running less efficiently?
Thanks @Tim_Gilbert
Yes that’s the one. I haven’t looked into the ‘low noise setting’ as yet. Daft as that sounds given my complaint but I want to make sure it’s set up properly as ‘normal’ before delving deeper. Also as we have had a period with near zero temperatures which isn’t recommended (but also when we’d probably most benefit from some reduction in noise).
I’ve also not managed to get the unit connected to our wifi as yet (our problem not the installers due to a faulty router) so was hoping to sort that before messing with it much more.
Of course this week has warmed up so it’s been quiet all day.
@Jonathan_Keenan assuming your heat loss is around 10-12kW (a bit of an assumption - but seems reasonable), then it is likely that your existing Daikin is operating normally and is just responding to cold weather by running at around full o/p power. This isn’t necessarily inefficient per se, so I wouldn’t worry about that.
But returning to the sound power ratings then were you able to choose a (intrinsically) quieter unit then that would help.
I suppose also because your Daikin is probably somewhat over-sized then the quiet mode suggested @Tim_Gilbert could actually work quite well even in colder weather. I’d be tempted to set the quiet mode on a timer, so that you could reduce the noise levels between say 1800-2000hr. The slight over-sizing of the unit may be beneficial in this instance as it may still be able to o/p say ~9kW in quiet mode (check the manufacturer’s literature to confirm). If this works with little loss of thermal comfort then it may be a useful way forward with your existing Daikin.
Yes, particularly during an experimental phase. Ideally you would be able to set it on a thermostat but that isn’t an option.
Edit: If you are into automation there may be an option to adjust the quiet mode according to outdoor temperature. In other words if the temperature drops below a figure yet to be determined then switch off quiet mode, otherwise if it goes above a possibly different temperature (to give some hysteresis) then switch on quiet mode.
Thanks @Tim_Gilbert and @zapaman
When the process started I spent some time on Heatpunk checking figures by putting in all the factors for the whole house. That came out with a heat loss of 10866w at -2.2c. It recommended a 12Kw Valiant ASHP.
As it was November and our old gas boiler was failing it became more important to get its replacement fitted than argue with an expert over sizing and as previously said the noise levels were the same for smaller ASHP. One issue with using the grant is that you are pretty much stuck with the installers choice of unit so we went ahead.
The idea of using the low nose mode could be a genius solution though so I am about to give it a go. The recent warmer weather has made things quieter so a good time to trial and see how it goes when temps drop again.
I recommend all readers to ask about one size down from first suggestion. It does no harm to ask. If time permits, which it didn’t for @Jonathan_Keenan, then try haggling and getting a second opinion.
I was lucky to get an installer who accepted my figures and as an extra bonus was prepared to use my existing cylinder. Having run my boiler at a low flow temperature definitely helped convince them.
Heat Pumps certainly can be quiet.
We just had a Vaillant 5kW ASHP installed. Happy to report I’m very impressed.
The 1st time I walked past the outdoor unit I thought it wasn’t running; I had to check the fan was spinning.
It is Quiet Mark certified. I’m sensitive to noise, so will look for this badge on other types of products!
Sorry to hear @Jonathan_Keenan had a noisy experience.
I knew someone whose ASHP was mounted on a wall, so the house hummed. So try to avoid that.
However our’s was quite noisy ~inside~ the house when the heating circuit was circulating – the whole house roaring like an open tap, would’ve driven me mad. Now resolved, thank goodness. Turned out they made a few…
Install Errors
Conclusion
A competent installer is essential if you can.
If you’re not confident it’s a good install (I wasn’t, quite rightly it turned out) it may be worth getting it checked e.g. by the manufacturer.
Amazingly, our install was free, along with solar PV & more loft insulation. ECO4 Flex funding.
Greater Manchester Eligibility Checker here.
But it means no choice of installer – you get what you’re given. In this case a rushed job by sub contractors unfamiliar with the brand.
A check by a Vaillant heating engineer cost £300, and extended our warranty to 2 years (up to 10 years if you take out a service plan).
Not free but paid for by the general public, who should be concerned that they are getting value for money. Clearly in your case they weren’t.
This is why I believe that there need to be stricter checks on quality of materials and installation.
I agree with your point about value for money as it’s often the case that grants bring out the cowboys which is the last thing we need.
However it is also important to frame the grants as an investment by the government not a give away. Aside from the catastrophic economic cost of ignoring climate change there is a cost to missing CO2 targets and ASHP uptake would do a lot to mitigate this. I realise this is preaching to the choir but the faming is still important.
Update!
I wanted to update in case anyone is following this and being put off getting an ASHP. Don’t be!
Mine has now been installed since Nov last year and I think I have finally resolved the nose issue thanks to the help from others on this thread. This backs up @Richard_Howarth points about taking care with installers. Unfortunately there is still a shortfall of experience in the UK so it is worth individuals getting up to speed to make sure they are not installing in problems.
For us; I still believe the ASHP unit installed was too big and it’s ‘max’ noise level of 63dB too high for location close to the house. Thankfully advice lead me to the ‘quiet’ modes. Our Daikin has ‘quiet’, ‘more quiet’ and ‘most quiet’ modes.
I went straight to ‘most quit’ expecting a shortfall in heating the house but none of us noticed any difference, even when outside temps dropped to zero again. What we did notice was an immediate reduction of around 10dB when the ASHP is most active which has made a HUGE difference. I believe this will also improve COP… so win, win.
My advice is to check carefully the heat loss assessment and recommended size of unit and check its spec, as it will be working at its ‘max’ noise levels several times a day during cold weather. No one wants to be sat indoors to sounds like being sat on a long haul flight. Thankfully this is now resolved and I couldn’t be happier with our decision to get rid of the gas boiler.
