Samsung Mono HT Quiet & DHW max. temperature limited to 55C

Hardware Heatpump
101

I have to say I find all these ideas to keep homes and rooms in homes at certain temperatures a bit odd.

It’s a commendable idea but it never works, does it?

Is it necessary?

If I am at home, I just adjust the temperature as necessary.

If I am not at home, I don’t care.

If the sun is shining, I expect to get a bit warmer, and when than happens it feels normal, the heating turning down doesn’t feel natural.

I expect my house to react to the outside world and it makes you feel alive and connected to the world.

A sanitised environment just feels a bit off, to me anyway.

If it gets a bit warm or a bit cool, so what? Nobody does this in the summer when they’re at the beach or at a park having a picnic, the sun comes out, you get a bit warmer, the wind blows a bit, you get cooler, it’s just life on earth isn’t it?

As long as it’s not too much I don’t care.

In any case, heat pumps are generally too slow to respond, and if it is done with wild variations in flow temperature it will just be inefficient.

I don’t think any of it is possible really, to keep a place at a fixed temperature whatever the weather reacting pretty much instantly?

This comes from somebody who uses their heat pump in fixed lwt, no room stat, no weather curves, just adjust the flow temperature as i see fit.

All my own opinion, as always :slight_smile:

1 Like
102

are you not trying to hit a moving target ? if you go from 2 people in a room to 6 the heat required from the heat pump will be less

103

Yep.

if you need trvs to keep room temperatures under control, then in my opinion, the design is wrong.

104

I agree system like homely is for the users who does not have knowledge or simply don’t want to deal with it. It’s definitely interesting idea if it really works as they claim. For now I’ve implemented +0.2c every 10 minutes then re-evaluate and eventually not increase or decrease in next run but I have some extra logic behind so let’s see. Primary control is by weather compensation of course.

Partially I agree. But there are some situation when some extra automation come handy. First I’m pretty sensitive to temperature fluctuation. I can register 1C difference anytime. I can register when pump is not running. With fixed flow temperature I can’t imagine how the pump could keep heating the house. During a day/night the temperature can fluctuate even by 20 degrees. If the sun is shining you need different flow temps otherwise you overshoot temperature pretty much. Cold northern wind and you need +3C of flow temperature to keep with target. OK you can use thermostat with some hysteresis and use higher flow temps but heat pump are not that efficient this way.

Ideal use case would be to maintain as lowest flow temp as possible while keeping your target temperature spot on all the time. Of course you are limited to emitters here so the maximum COP will be determined b this. But what you can optimize is improving efficiency with regulating flow temps.

On a cold night it can be -10C then during a day it can go up +5C so I can’t image to deal with flow temps manually. The temperature comfort would be hit hard. I guess minimum is weather compensation. Room compensation is maybe extra but it can give a bit of more comfort.

Each to their own of course. Also one issue with just a flat curve is that for example I’m turning of pump at night for 6h. In the morning temperature drops depending the outside temp and if I wouldn’t modify the temperature curve it would take a long time to reheat the space.

If it never worked I’m not sure, it’s true that the response with heat pump is much slower than for example eclectic boiler I had before. But with electric boiler I also had weather compensation set and more importantly I had TRVs in every room!

I can say this was most comfortable source for heating I had though most expensive. With heat pumps TRVs are no go so your system must be designed properly to get best results. I only have Type 21 rads which are not ideal for heat pump but also not the worse so try to keep with them as much as I can but I fear I can’t go over SCOP 3 with these… Welp, can’t have everything :slight_smile:

105

HI Michal,

firstly, you sent me a message that I never replied to, very rude of me, I wasn’t so well at the time and didn’t think I could give you the sort of reply you deserved.

Please accept my apologies.

I have a smaller heat pump now, 8kW instead of 9kW but it is still double what I need, but the smallest Daikin make, so the smallest I could have.

In regard to what I do.

I barely change my flow temperature yet my house stays at more or less the same temperature the whole time.

The temperature you see in my data is upstairs in a bedroom, it’s where the sensor works, and maybe all I care about anyway, I know how warm it is downstairs, as I am there most of the day and I can see it in my Daikin app.

What really happens.

It runs at a constant flow rate.

As the heat loss of the house changes the dT between flow and return changes, I get more heat normally as it gets colder outside, without doing anything.

I normally vary my flow temperature between 30c and 32c but it spends most of the time set at 31c

The heat pump does also vary it a little, not sure why, but it does.

So my house is pretty steady and I rarely change anything, just fixed flow rate and fixed lwt.

The temperature varies by a degree or two, rarely any more.

If the sun shines, it gets a bit warmer just as it would anywhere outside and it feels natural.

My data again, if you ever want to look

Emoncms - app view

I just thought to add.

My room temperature generally varies by less than the 2c hysteresis on Daikin’s `not so marvellous’ Madoka room controller! And at a much better COP than that thing can manage!

106

One problem I think with a wdc is that the same outside temperature doesn’t always feel the same.

I have flown back from Latvia, left at -20c and arrived at Stansted at +3c and I am sure it felt warmer in Latvia.

Sun shining at -20c felt better then freezing rain at +3c.

And the same with the heat pump, one day 2c gives different performance to another at 2c

I am sure there is a scientific explanation but I guess a lot has to do with humidity and wind chill.

107

Disagree as a bedroom can be a home office for most of the year but need to be kept cooler for a visitor to sleep in. Likewise with single room solar gain issues. Even a simple small kitchen can overheat when the oven is on for a few hours.

1 Like
108

Depends, UFH in a very well insulated/airtight home can be self regulating as a small change in the dt between floor/air temperature gives a meaningful change in heat output. But few normal people live in such homes.

1 Like
109

I disagree too :slight_smile:

I have slept in loads of places, hotels around the world, in trucks, back seat of coaches (not so great!) etc.

I don’t care if it is 17c or 23c (or even more varied), if I am tired I go to sleep.

Just too sensitive, what do these people do in the summer in a `hot’ bedroom?

Anyway, if it’s a bit hot, open a window?

But I do agree in a way too :slight_smile:

If somebody wants trvs, go for it

But you probably can’t have the ultimate environment and the ultimate SCOP with a heat pump.

110

This is about how my heating works at a pretty much fixed lwt.

My radiators are so big for the size of the house, they act more like ufh.

@Michal_S

1 Like
111

Great way to increase both COP and electricity usage.

112

Not really.

How much extra electricity do you think you may use?

Not much. It’s an office being used for an occasional visitor? It’s not going to be for long is it?

In fact, quite often, nothing, maybe even less.

Some people even like a bit of fresh air when they are sleeping. I know many people who always have a window open when they are sleeping.

Heat pumps are funny things, electricity consumption isn’t proportional to heat output and many times with my heat pump creating more heat actually uses less electricity. It was the same with both Daikin heat pumps I have owned.

You really need to know your heat pump to get the best out of it!

113

I re read this @Chris_Hill

Did you mean me trying to hit a moving target?

In my house, if 4 more people come into the lounge then the temperature increases.

And then, the radiator output drops because the room temperature is higher.

And this goes on a bit until it’s all about where it started with only two people in the room.

Maybe a little warmer, but to be expected, I’m not that sensitive to it I guess and I don’t care much anyway.

1 Like
114

Normal human metabolism produces heat at a basal metabolic rate of around 80 watts so 4 more people, 320watts, maybe a bit of AC required sometimes?.

115

Who knows?

If only I had four friends!

2 Likes
116

No problem, but thank you’ve found time to reply now. I have 8KW but in fact it’s 14KW unit so don’t tell me about what is big :slight_smile: It all goes down to modulation. Does not matter how big is but how low it can modulate. Mine can go as low as 800W which is of course pain if there is above 5C outside. From 5C upwards I can’t run it without thermostat, because it would cycle like crazy. So I believe your 8KW Daikin can go much lower, maybe 2X ? What’s your minimum compressor input ?

Also you have oversized emitters which is of course great with combination with heat pump. I don’t have this luxury so maybe your emitter are is twice bigger than mine so you can afford running at 30C flow temperature. Also your indoor temp is much lower than mine so efficiency of mine radiators suffers even more. Thermal mass of your system or people who have UFH is much much bigger than my 9x Type21 radiators. I don’t have any buffer tank or anything so I have to play with cards I have so reaching SCOP 3 with this system looks like a challenge. I can forget about 4 or 5 this is impossible with my system. However, my heat loses are not that big that rework would be rentable especially with planned FVE in the near future.

Today is a very cold strong wind and I cannot reach my target temp even with 43C flow temp. Normally I can do it with 40C so at this temperature my room would be 1.5 below target.

My goal is to keep temperature steady and all the time. In winter I have 2 air-condition units and I maintain exactly the same temperature of 23C so for me winter/summer no change in indoor temperature. I like things steady. Of course if you don’t mind these temp fluctuations I have no problem with that.

Your data are insane, congrats. I can only dream of such values :slight_smile:

Do you have dT set to 6C ?

If you are interested you may have a look here:

https://emoncms.org/app/view?name=SamsungHTQuiet8KW&readkey=08e537b32c860fb7dde97944728b60a9

I agree, depends where the sensor is, if the wind is blowing and so on. That’s why pure temperature curve is not sufficient for us “stable” like guys :slight_smile:

I have problem with this. 17C is very low for me and I would feel cold on my face which I don’t like. I can tolerate maybe up to 20C but not any lower. And in the summer I’ve replied to you - two airconds :slight_smile: BTW, I can’t stand temps more than 26C in summer, funny is I don’t mind low 20 :smiley:

I think Chris addressed this to me. It’s right it’s a big difference if the room with thermostat is occupied by people, TV running etc. This has impact of course and therefore for us sensitive guys a room compensation is a must :slight_smile: The only question is if I can implement in in a responsive way, I’m affraid it’s not easily possible with heat pumps…

117

I don’t think my room temperature is much lower than yours.

My sensor is upstairs.

It is generally 19c to 20c in the bedrooms.

Downstairs is generally 22c to 24c.

I don’t think you go warmer than that?

My heat pump goes down to about 450W normally.

My dT is set at 10c, but I don’t get there very often. Its a Daikin thing, it’s the only way I can keep the flow rate steady, set a dT it can’t get to.

It will go lower but efficiency is worse and heat pump isn’t happy below 30c flow.

I don’t want my bedrooms at 17c either, I don’t like it.

But if I am in a hotel and it’s cold, well it’s cold.

And if I have to sleep in a truck, or a coach, and it’s cold, well it is, still need to sleep.

I guess my point is, it’s difficult with a heat pump if you want efficiency too.

You could do it, run like a gas boiler, shut down rooms and increase flow temperature until other rooms shut off.

Heat pump stops, then one room gets cold and needs high flow temperature to keep heat pump running.

A mess.

Best just to get emitter sizes and heat pump correct in the first place.

Anything else with a heat pump is a compromise and compromises cost efficiency.

118

I though the 9kW unit was the same as 14kW, and the 8kW was the top in its family?

119

What brand you are talking about? Samsung HT Quiet R32 were 8KW, 12KW and 14KW… All have the same compressor only restricted by software. Nasty stuff from Samsung. Very nasty… I was in impression I’m buying 8KW heat pump and hope it will modulate low enough…

I have 23C everywhere… Upstairs, downstairs…Only at night I either turn off the pump so the temp over cold night decrease withing 6hours maybe 2C. Or I lower flow temp to 38C.

My radiators and pump is not happy below 40C, the min I can get is 38 but then efficiency in hotter days suffers because my small system.

dT=10 nice… I have set 5 and I can achieve it when colder. In hotter temps it’s a problem. Min heat output of the pump at nominal input power is 4KW so if it had to go down (lowering compressor speed to min and outdoor FAN to min) efficiency suffer. Damn Samsung didn’t state clearly this is not 8KW pump but 14KW. Hate them for this. I swear I’ve never seen this at another manufacturer. Lazy pigs put same compressor in all their R32 ranges. I will never buy this brand again just because of this. So if it breaks I will not cray about it. Costed me 8K euro 5K with subsidy so it’s not that a big loss :slight_smile: In 5 years it will pay off and then let’s see how long it will work.

120

Don’t tell me this pump is not stupid.

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Until 00:26 I have set flow temp 43C… Zigzag all the way, power fluctuating from 1600 to 1900W so LWT fluctuating like crazy as well… Then I set flow temp to 38C because I’m going sleep…Bang, no power fluctuations and steady power consumption. I ask why is that. Why pump modulates like shit to maintain 43C flow them. Why it can’t simply rung at contact 1750W to maintain 43C ? Why does it need to fluctuate like that ? Can’t get this…