Heat Pumps - post here.

veXual

Hi Folks, seems to be a lot of knowledgeable people here so just wanted to ask a question. I'm in a new build with a 12kw Samsung heat pump installed looking at the settings on the control panel for the low and high target values for the water temp for the UFH both were set to 27c by the engineer who installed it. This surely can't be right can it?

Judging by comments I've read from people here my heating shouldn't be consistently calling for heat but it seems its demanding it quite frequently now the weather has cooled. Should I adjust these settings to a low target value of 45c and a high of 30c ( I've based these numbers off a tutorial I spotted on youtube)

Thanks

KCross

It depends on your house but you should be aiming for as low a value as you can. Less than 30°C is what you should be after.

Definitely not 45°C.

A bit odd that low and high are both set to the same... that might be a mistake. Your first port of call is your installer. Ask them to advise, they should know the system.

Mr Q

https://www.boards.ie/discussion/comment/119962946#Comment_119962946

It must be a big house if it's new and needs a 12kW heat pump.

My max flow temp is set to 30°C and works fine on UFH during the winter. Not a Samsung.

graememk

https://www.boards.ie/discussion/comment/119962946#Comment_119962946

Leave it be, the lower the flow temperature the more efficiently the heat pump runs.

Underfloor heating usually run at "low" temperatures

It running at a low speed for a long time, is better than it running at full power for a short time, cutting in and out.

Only consider changing it if you are cold in the house.

ConorC1

My UFH temperature setting is at 40 degrees. I have never changed it. If this water is servicing radiators on the upper floors of the house would that be the reason it may seem high compared to what people are advising in this thread?

THE ALM

https://www.boards.ie/discussion/comment/119952614#Comment_119952614

thanks redmagic68, way too much going on at the minute but I have a few takers should I ever have the time.

THE ALM

https://www.boards.ie/discussion/comment/119938631#Comment_119938631

Further to my earlier query.

What equipment is physically involved in the install, or does it vary?

Is it a matter of removing the boiler and re-plumbing in the pipework? We have a relatively simple install as is, with the flow split for radiators and hot water driven by two pumps. Recently upgraded the cylinder to a well insulated 210l tank so thinking it won't need replacing again. Boiler is in a utility against the outside wall where we could install a heat pump so pipes could be carried straight out through the wall.

Thanks

redmagic68

https://www.boards.ie/discussion/comment/119971575#Comment_119971575

So every system is fairly similar depending on the design lay out. Your heat pump comes on like your boiler and in my case sends dhw to the storage tank with one pump. There are two further pumps then for the two underfloor manifolds one for up stairs one for down. There are a number of electronically controlled diverted valves also but these are quite small. Our tank has 3 coils one for the heat pump, one for solar and then an immersion heater. I should imagine your set up will be similar but with rads. There is also a top up valve allowing you push some water into the system if pressure falls a little at the hp after depressurising to clean filters etc but this is generally off the mains.

TheUnderfaker

Looking for a little bit of advice (and apologies if going over old ground).

New to the heat pump world (Daikin 12kwh) and have just been checking out the settings now that the cold snap has hit. We have radiators and no UFH.

I noticed that the heat going to the radiators is set to 50°C so they get pretty hot. The house is lovely and warm, but I'm wondering if having the temperature so high is the most efficient way to run a heat pump? Would having the radiators set to a lower temperature and the heat pump running for longer periods at a time generally be a more efficient way to run the system?

THE ALM

https://www.boards.ie/discussion/comment/119973738#Comment_119973738

Thanks for that.

Calahonda52

https://www.boards.ie/discussion/comment/119971575#Comment_119971575

Have not read the whole thread fro your posts, are your rads up to it with the reduced flow/return temps from the HP?

THE ALM

https://www.boards.ie/discussion/comment/119974782#Comment_119974782

That is what I am trying to figure out.

If my calculations are correct then the heat loss for the house is approx. 9kW and the radiator output is approx. 16.5kW so just trying to figure how these two relate to each other? Most rads are k2 with a few small k1 in ensuites.

Another question is the need for a buffer tank as I am seeing conflicting information in regards the need for one. It would make things a lot easier if one is not required.

EDIT: Radiator sizing - is it simply that a room as a heat loss of e.g. 900w and therefore needs a radiator with an output of 900w?

redmagic68

A buffer tank where you have a high flow temp coming from the heat pump that could be to hot going to a floor or where you want to reduce cycling of the heat pump and use it as a store along side a Hwc. Inverter heat pumps can alter their leaving temperature to suit the demand being placed on the system. Fixed output heat pumps generally need a buffer thank.

veXual

Thanks to all who replied on my post. We're only a few weeks in the house so some acclimatization needed to the new system. Being your typical Irish person I'm accustomed to heat being blasted from radiators and heat in a room being 'hot'. I know a few people here have spoken about temperatures of 18c in rooms being plenty warm but I'm not finding that to be the case so far. It feels cool to me though it may just take some getting used to.

I do want to ask about peoples experiences with heat recovery and the temperature of the air being supplied to the rooms. Has the air from the vents felt cold to some? I'm questioning the temperature of what's being supplied into the rooms in my house. Almost feels as if there's a breeze in some places though that may be air tightness that needs to be addressed. I haven't had an air tightness test performed as of yet and am in the middle of my BER assessment so may get more insights there when completed.

Stats in each room do indicate that they are on consistently to maintain the temperature and at times are struggling to hit the temps I've set though it is the coldest weather we've had in a while so it may not be the best time to draw conclusions. Being a new build and having just moved in I've become obsessed with the heating making sure its running effectively, from both and energy and cost perspective, while keeping the missus and child happy and warm!

Edit: For context my system was installed by Joule - 12KW Samsung heat pump with invavent MHRV in a 220m2 bungalow.

ECO_Mental

https://www.boards.ie/discussion/comment/119988350#Comment_119988350

I think you might have the same HP as myself 12kW Joule Samsung and the same size house. I have mine set to 18-19 deg in the bedrooms and halls, the living rooms and kitchen etc I have set to 20 deg otherwise it can feel a bit cool. Again it all depends how good your house holds the heat.

For what its worth with the weather over the past week not getting above freezing my HP has been getting a right proper workout and I am using quite a bit more than I though I should. That saying we are in an orange alert cold weather snap and my heating has been kicking in all day. That saying also I have had builders in the house today and they were in and out all day leaving the door open and I wasn't there to turn off a stat that was next to a door. 🤬

What I am saying is this weather is a bit exceptional and I wouldn't read too much into these days. Just keep an eye on your stats it could be one room that is set a bit too high and keeping the HP on, but in the end of the day you have to be warm.

For what its worth I have used since midnight last night to now (20:00hrs) 52 kWh eek!!....

My 7 day moving average has gone up to about 37 kWh/day over the last week, I should be around 22-25 kWh/day going by last Feb/March.

I have A1 rated house (A2 without the 6kW Soalr PV) so its well insulated and airtight.

Nelbert

I don't feel so bad about my 30kWh+ daily usage on the HP the last few days now (been actively trying to control it to little avail).

Eco_mental if you have HA have you got stats that support being integrated?

I set up an automation to turn off the relevant stat (heatmiser stats with neohub for me) if a external door or window (via ring alarm integration for contact sensors) is left open for 5 minutes.... Only turns back on after being closed again for 15 minutes - this is about what it takes for the air temp to settle again in most rooms and either call for heat or not.

ECO_Mental

https://www.boards.ie/discussion/comment/119989938#Comment_119989938

I have got Joule stats and they dont have connectivity but I am thinking of getting stats in the future that can be connected to HA but not this winter maybe next summer project. Funny thing is I do have a Zigbee door contact on the door in question but I don't have any automations set up for it as I only put it in a couple of weeks ago along with a load of Zigbee temp sensors.

Over Christmas I might look at some automations or even some alerts to be sent.

I kind of wanted to let they system work away to be honest as well in the really cold weather to see how it performed and have been tweeking it. I noticed a temp setting of 1 degree too high in a room can call heat far too much. I had the bedrooms set at 19degs and rooms were kicking in a lot during the night but I lowered them down to 18.5 and it has improved it no end.

Nelbert

You can get HA to send notifications to your phone or alexa.... I had a close the f'n door notification that went out..... It wasn't popular....

Still.... Door sensor for the fridge for the same reason is coming.... Once you start monitoring energy usage it's a slippery slope.

poker--addict

I used 114kw total yday. Typically 22kw with no pump in summer so 92kw on geothermal heat pump!!

I have pump set normal (as low as possible) all night. However a slightly higher setting is called for the hour before the day rate elec starts. And then set back to slightly lower for the day rate period, with an hour on normal in the afternoon as I figure that should stop the system getting too cool.

pump ran 18 hours yday! Depressing!

poker--addict

Very interesting to see the automation and impact of a door open- and temp settling time. Always wondered impact of opening doors when we spend time measuring tiny amounts of heat loss and spending whatever to get from b2 to b1 then the kid leaves the door open for 2 minutes.

Takca

Just found this tread while trying to find my way around the heating in a newly renovated house,

I thought I my usage was excessive (see graph) which lead me here, I'm now thinking the power usage

seems reasonable.

Some details on the house, 285sqm, BER A2

3 zones (downstairs, upstairs and a granny flat area), also includes a unheated garage area

rads, no underfloor heating

demand controlled vents (no heat recovery)

I've felt that the DCV was pulling in too much cold air leaving the place feeling

chilly sometimes (and causing the heating to run more)

So I turned off both extractor fans last week for a day (see outlier on graph were usage goes from 

the high 30s to 24 kwh, But wasn't happy with the vents being completely off so am now

experimenting with partially running it.

Leaving one on the turning one off (amount varied each day, The Fan I turned off covers the granny flat area (currently vacant with stat set to 16c) and the kitchen/utility.)

Anyways here is the graph of daily consumption of heating upto the 11th (excludes hot water)

along with a 24h rolling average of the outside temp. I only have a few months of data

randombar

https://www.boards.ie/discussion/comment/119991004#Comment_119991004

Would you think of retrofitting MHRV system? I did it last year. Wasn't too bad.

randombar

One of the guys sent on his HP stats for Nov.

237kwh In -> 709kwh Out

Current on "Free Saturday" smart meter deal, essentially cost him €92.54

That equates to 80 litres of Kerosense I think? €92.40

Would be ok if they were the same price if he didn't fork out 8 to 10k for the A2W?

I'm guessing his unit is behaving badly + his elec rate is bad??

https://www.boards.ie/discussion/comment/119991585#Comment_119991585

Do you mind me asking, what kind of money are you talking to retrofit a MHRV? Just ballpark

randombar

https://www.boards.ie/discussion/comment/119991630#Comment_119991630

Couple of years ago but it was about 3.5 to 4 k ex vat for a detached 4 bed. That's for the hardware. Good few weekends in getting it all in.

https://www.boards.ie/discussion/comment/119991671#Comment_119991671

Hmm, thats not so bad. By the sounds of it you did the work yourself, I'm guessing it would be about 70% more if I was to get someone to do the work for me (I'm not the handiest at DIY)

THE ALM

https://www.boards.ie/discussion/comment/119991630#Comment_119991630

Recently got a quote for the equipment for a 4 bed bungalow with a view to retrofitting MHRV, the equipment varied in price from about £2300-£2700 + vat.

Jinglejangle69

https://www.boards.ie/discussion/comment/119991614#Comment_119991614

Why does he presume he’s gonna save money with a heat pump over a boiler?

randombar

https://www.boards.ie/discussion/comment/119991723#Comment_119991723

few youtube videos and crawling around in an attic. Be grand.

randombar

https://www.boards.ie/discussion/comment/119991818#Comment_119991818

I always thought that was a given, I heard of a statistic somewhere that it would half the cost of your heating bill. Instead of paying 800 in oil you'd be paying 400 in elec. That's probably a very old one though.