Hi, I have the same model and also live in a quiet location. Our bedrooms are on the south side of the building and the ASHP is on the north side, so we never hear it at night. The kitchen is on the north side and we don’t hear it there either. The main noise is the water pump in the porch next to the kitchen and the flow through the kitchen radiators, which we have got used to. 

There are quieter models by other manufacturers I am sure and there are a number of issues with Samsung installs that you might want to be aware of. These include installers insisting on adding a buffer tank, poor location of the wired controller, short cycling if oversized and unrealistic claims about SCOP. These issues are not limited to Samsung to be fair. However, I would advise you to do a lot of research before you go ahead with an install in order to get a good result. There are a lot of forum members who have described poor installs. Hindsight as always…..

Hi @tobyg.  We've two of those Samsung models, installed Feb 22. 

I did understand that, at the time at least, they were amongst the quietest available. Not sure how they compare now. They do have a 'quiet' setting (which reduces compressor power) although tbh I've never used it.

Our heat pumps are located on a north wall, adjacent to the east wall of our bedroom. They purr away really quietly when temperatures are not too extreme but they start to work harder the lower it gets and below 0°C you can hear them a little. It's really about the same as our fridge though and I zone it out completely. My wife has hearing like Jamie Somers* though and she notices it a little more. It's not an issue.

I'd endorse completely what @mike-h has said above as well. You need to understand the design, your heat demand situation and be prepared to spend a bit of time learning how your house responds and optimising the weather compensation settings. Good luck on your journey. 

* Apologies to anyone under 55 for the 1970's cultural reference. 😊

Simon

I have a 16, which is the 12 without the de-rating. I wouldn't worry about noise as a primary decision criteria. It chugs away somewhat when its sub zero , but nothing to stress about. we are in a very quiet area, the (not very much) traffic from 2 streets away is louder than the HP. unless you stand literally next to it, have it outside your lounge window or something, you'll not notice it. Given that the 12 is a de-rated 16, I'd not expect it to modulate down below about 4kw (@mike-h , @dunlorn ?) .

take your point that with ECO4 you can't pick and choose your system. In which case the 2 most important thing to focus on are

- getting the system design right - which might be an issue with ECO4. From other people who've posted on here they seem to insist on buffer tanks, Low Loss Headers, TRVs, zone valves, all of which are not best practice for getting an efficient ASHP .

- getting the system size right. For which you really need to know your heat loss. Do NOT trust the first heat loss number you've been given. If you have the willingness to do so, I strongly suggest you do your own heat loss calculations. There are tools linked from this forum, there's heatpunk.co.uk, theres openenergymonitor.

If the HP is too big (See my point that it likely won't modulate down below 4kw) then in mild weather you are pretty much guaranteed to have a lot of poor performance issues due to cycling which is caused by oversizing. 

To get some rough ideas whether a 12 is in the right ball park or not:  How big is your house (m2)? type? how old? insulation levels? what's your current heating system, do you have any figures for how much energy you use over decent periods? smart meter data? if not, could you measure it - check the meter every 24 hrs in cold weather?

@iancalderbank Yep, 4kW is probably about right as a minimum. I've not measured generation at that end of the scale but the lowest stable power consumption I've seen is 1kW at milder ambient temps (8-9 deg or so and above), which probably means 4kW or so being generated.

Thank you very much for the replies, which are very helpful, and pretty reassuring in terms of the noise question. I'm going to do a bit of homework now on the other issues people have flagged.

Posted by: @iancalderbank

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Given that the 12 is a de-rated 16, I'd not expect it to modulate down below about 4kw (@mike-h , @dunlorn ?) .

The lowest production that I get before it cycles is 3.6kW, although my Sontex flow meter reads lower than the Sika that the Samsung displays. Do you get a choice of installer with ECO4?

Thanks @iancalderbank. I've been looking at the installation company's calculations which give heat loss as approx 16,000 kWh/yr, which with 4000 for hot water gives a total heat demand calculation of 20,000. Contrasting with this, going off the meter our energy use (gas) for the last 12 months is 10,000 kWh/yr; I'm going to ask them why there's such a big difference, and if sizing the HP based on the higher figure means there's a risk of over-sizing. (I note that the next Samsung down is 8kW, nothing in between).

In terms of the questions you pose: house approx 150 m2, built 1900 with solid stone walls; extensions all round the ground floor with cavity wall insulation, while internal wall insulation will be installed on the 1st and 2nd floors as part of the same ECO4 package.

@mike-h, we don't get a choice of installer, but we've been reasonably impressed so far with this company - they spent two hours surveying the property, have been transparent with their calculations, and haven't tried to provide false certainty.

Thanks again for all the advice.

Posted by: @tobyg

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 we don't get a choice of installer, but we've been reasonably impressed so far with this company - they spent two hours surveying the property, have been transparent with their calculations, and haven't tried to provide false certainty.

Thanks again for all the advice.

That’s a positive start. Your next telling sign will be the quality of the quotation and the detail provided.

@tobyg the vast difference between your gas usage and their estimate is a significant concern. also, a gas boiler is at best 85% efficient. so your metered use of heat was no more than 8500 kwh .

you don't live any part of the country subject to extremes? e.g at the top of a hill in the scottish highlands? Do you (sorry to have to ask this) "properly heat your house" at present? i.e. do you keep all rooms at a comfort temperature (generally taken to be 21, but some people vary of course)? As not doing that is one possible reason why gas use might be lower than their heat estimate. but the more likely is that they've oversized. The MCS method is absolutely notorious for this. which is why I suggested to do your own. has the extra insulation been allowed for in the calculations?

Does your gas run your hot water as well? do you have an idea whether your hot water usage is high (large family lots of bathing) or low?

try to do the following if possible. the objective of this is try to get another of the heat loss of your house based on measuring short term gas usage to give an "empirical" (i.e. measured) value.

• run your hot water on electric (if you have a cylinder with immersion). If not, minimise your hot water use as much as you possibly can.... don't have a bath ;-). Or, do all your  family's bathing in one block, noting the gas readings immediately before and after so you can subtract that from the heating data.
• turn your boiler temperature down as far as you can (this is so that its more likely to be able to run constantly)
• run the heating constantly, or as constantly as you can - the aim is to run it 24 hrs, or at least 16-18 hrs, at a comfort temperature.
• once the house is stable at comfort temperature, start writing down the gas meter readings hourly. write down the inside and outside temperature for each one as well.
• If its a smart gas meter, you can use the "hildebrand glow bright app" (free but you have to register an account for secure access to your meter data) to pull the data from the smart meter network for you.

try to do it it on some days with different outside temperatures. its just as important to do it on a mild day (~7C) as a cold one (sub zero). then plot it all in excel. Difference in gas meter over time *.85  = kw heat used by house during that period. then plotted again the outside temp will show the trend.

the issue with the samsung 12 is that it really a 16 with different tuning. it downrates to the same level as the 16 (i.e. to about 4). I'm fully expecting your heat loss in mild temps to be a lot less than 4 kw. Also you've said the insulation will be very much improved after this work, so it'll go down again. The samsung 8 doesn't derate particularly well either (about 3kw from what I've read). you have to expect some cycling in mild weather, it goes with the nature of a heat pump system, but if your system is vastly oversized, you will get poor COP in mild weather which is exactly what you don't want. This is because the mild weather days occur far more often (assuming you aren't half way up a Cairngorm), so you want those days to where COP should be great (into the 4's) and saving you lots of money.

Thanks very much again @iancalderbank for your advice above and efforts to help. I've started having a go at measuring as you suggest. In terms of some of your other points - we're in Gloucestershire, so no big extremes here; I'd say we have the house slightly less warm than average, but not by much, though often the radiators are off in the bedrooms. I wondered whether they are allowing for the extra insulation - I'm going to ask. Our hot water use is perhaps a bit higher than average, but not by a lot.

We have a meeting with the installation company tomorrow; I've put the question to them about the discrepancy between our gas consumption and their heat demand calculation - we'll see what they have to say. I'm wondering if ECO4 ties them into some matrix which prioritises toasty warm homes in cold weather without balancing that sufficiently with other considerations (i.e. they may not have much room for manoevre themselves). They quote the EPC in their assessment, as it seems they have to, (though I don't think it's part of their actual calculation) and that's on a whole other level - energy required to heat the property given as 33,000 kWh/yr (incl 3000 for hot water).

I suppose in terms of the worst that can happen, the risk if we're over-sized is big bills, and if we're undersized I think we're more concerned about the hot water not being hot enough, than the central heating not pumping out out full blast.

Ah well, so we've had our call with the installers. The calculations they are required to use (I assume required by ECO4) result in the 12kW heat pump in our case, and there isn't the flexibility to do anything else. They also said that the heat demand for a heat pump system isn't directly comparable to our energy use with a different fuel (i.e. gas) - which still doesn't make sense to me. But I'm sure part of what is going on here is that the target design temperature they have to use is higher than we have been having. The bottom line funding-wise is that it's this, or nothing, and we're going to go for it. (The only thing we're left debating is whether, with a potentially oversized heat pump, it's beneficial to go one size bigger with the hot water cylinder, to take advantage of spare capacity, as it were, or whether the reverse is true?)

Thanks for all the input everyone.