New build danwood.

[Danwood build]

Hello folks! 
 

I hope you are all well, I’ve built a danwood 206 in the last 2 years in north east Scotland. Pretty happy with it all.. just looking for some tips on my heating system  the after sales with danwood isn’t the greatest to be honest. 
 

I’ve got a nibe air source heat pump with UFH on all the downstairs level, upstairs we have radiators, and UFH in the bathroom suites. 
 

We also run a Zehnder ComfoAir Q, heat recovery system. 
 

Like everyone I’ve taken electricity for granted and didn’t even think about it up until the price hike recently. The system we run is becoming increasingly unaffordable in my opinion. I’ve one 2 young children one room downstairs for the infant and her mother has UFH set about 20degrees, my eldest is upstairs with a radiator again, nothing silly in temperature. 

 

I know we are in a cold snap, but we are using 60kw a day just now. 
 

I monitored it recently when it was average temperature (Circa 10 degrees)  I was using around 30kw a day. 
 

Is this normal?
 

My question with anyone with experience, should my heating be on timers, or does it take as long to heat up a UFH it’s not economical using a timer system for it? Or is there any tips to make this more economical. 
 

I keep thinking about ripping out Heat pump and replacing with oil boiler as it would be cheaper to run. Any advice appreciated!

 

I do have the wood burning stove in my open plan living space, so no heating is used in any communal areas. 

Id recommend danwood highly, build quality was good, and fantastic the speed they work at, anyone that wants to ask questions about my specific build I’d be more than happy to discuss with them. 
 

Regards 

 

 

[ProDave]

1 hour ago, Danwood build said:

I know we are in a cold snap, but we are using 60kw a day just now. 
 

I monitored it recently when it was average temperature (Circa 10 degrees)  I was using around 30kw a day. 
 

Is this normal?

When it was 10 degrees, the delta (difference between inside and outside temperature) was about 10 degrees.

Now the outside temperature is 0 degrees or lower, the delta has doubled, so you would expect the amount of heating to keep the same internal temperature to double.

 

Mostly it is down to the insulation levels.  We don't know how good or bad your house is, what insulation and air tightness levels etc?

 

What is the ASPH flow temperature set to?  What is the UFH temperature set to? Those are things you can adjust to try and make the ASHP run as efficient as possible.

 

I assume you had an as built EPC issued, what energy rating did that achieve?  What does that say about estimated heating energy use?

[JohnMo]

A few questions

Whatis your UFH flow temp?

Are you doing a fixed flow rate or weather comp?

What is the ASHP flow and return temps?

How big is heat pump?

Do you know your heating design kW?

Does your system have a buffer?

 

[Bozza]

Welcome.  Funnily enough I may have been inside a 206 in AB51 area when considering building with Danwood.  Might even have been yours.    
 

@JohnMo & @ProDaveasked all the relevant tech questions & are more knowledgeable than I with such issues.  
 

Your house has a big open plan living hallway area double height space.  Very nice but is that going against you as the heat from your UFH rises up it’s not getting trapped within a standard space or is it that area that you don’t use UFH with.   Also if I recall the Danwood windows aren’t 3G or am I mistaken.  Is that a factor, also do you get any solar gain.  I take it you don’t have window vents due to HR system.  

 

Yesterday I had my ASHP serviced and talked through setting etc with my helpful engineer in light of weather. Ultimately the very cold weather will inevitably affect demand  on system.  In summary though, no to having system running constantly.

Danwood houses are well insulated. 

 

So there are 3 relevant things. 1. Optimum settings  2.  High demand on system due to current weather.  3.  High electricity prices.        2 out of 3 are out of your and our control. 
 

I’m fairly certain that running your ASHP constantly will not be the solution.   Is the ASHP running when you’re not asking for heat etc.  are you trying to heat water at same time as central heating. I think it’s most likely a settings thing TBH. 

Don't forget you need to consider your average annual useage - during the summer it will or should be very low.  What’s your annual KW useage on your system.

 

 

 

 

 

Edited December 15, 2022 by Bozza

[Luke1]

I've got a Nibe controller, so if you have any specific controller settings then I can help answer.

 

Unless the curve has been set to flat line the default system should be set up for Weather Compensation.

If you could take a look at this and provide a picture or details requested above then that would be a good start to getting some answers.

 

(Do you have Nibe Uplink so that you can monitor / control the system remotely?)

[Danwood build]

A lot of technical questions 🤣 I’ve taken some pictures from my controller… the house used 10900kw last year at 13p a kw!!!

 

[Danwood build]

[Radian]

11 minutes ago, Danwood build said:

A lot of technical questions 🤣 I’ve taken some pictures from my controller… the house used 10900kw last year at 13p a kw!!!

 

Don't let @SteamyTea catch you dropping your h's 

I take it your 10900kWh/year was just space heating and hot water? The Primary energy indicator of 62kWh/m2/year seems a bit pessimistic (as usual).

[Luke1]

Can you go into indoor climate -> advanced -> curve and send a picture of the heating curve you have?

[ProDave]

You have a pretty good EPC rating there. Fit some solar PV and you would easily be up to an EPC A which is nice to have.

[JohnMo]

First observation is the flow temp is high at 47.8 from the heat pump.  Do you know what your UFH flow temp is, or does your floor heat up quite quickly?

 

If you could reduce that flow temp to about 35 you could gain an additional 1 on your CoP from low 2s to low/mid 3s.  That could save 10kWh a day!

 

My flow in the floor is 29 as a reference, it's -7 here, house sitting at 19 inside.

Edited December 16, 2022 by JohnMo
Saving in electric added

[Bozza]

So your house size & your EPC are almost identical to mine.  And we’re obviously experiencing same outside temperatures being local.  I’ve looked at my overall electricity bills, and ASHP stats to help you make comparisons:

 

overall household electricity usage in July 22 - 11 kw per day.  Over past three weeks - 41 kw per day.  house occupied pretty much 24/7.

 

in terms of ASHP annual useage etc please see below.  Hope this helps.

 

 

 

 

 

 

Edited December 16, 2022 by Bozza

[Kelvin]

I watched a Danwood go up just near Blairgowrie and it was impressively quick from the foundation to up and rendered. Nice little bungalow. 
 

 

[Danwood build]

35 minutes ago, Luke1 said:

Can you go into indoor climate -> advanced -> curve and send a picture of the heating curve you have?

 

10 minutes ago, JohnMo said:

First observation is the flow temp is high at 47.8 from the heat pump.  Do you know what your UFH flow temp is, or does your floor heat up quite quickly?

 

If you could reduce that flow temp to about 35 you could gain an additional 1 on your CoP from low 2s to low/mid 3s.  That could save 10kWh a day!

 

My flow in the floor is 29 as a reference, it's -7 here, house sitting at 19 inside.

 

[Danwood build]

That any help? Really appreciate feedback so far.  Both radiators and UFH are on constant just now. 

[JohnMo]

So was your first photo showing the heat pump showing 47 degrees flow temp, on DHW heating, as it does not be match the heating curve?

[Danwood build]

15 minutes ago, JohnMo said:

So was your first photo showing the heat pump showing 47 degrees flow temp, on DHW heating, as it does not be match the heating curve?

DHW?

[Danwood build]

24 minutes ago, Kelvin said:

I watched a Danwood go up just near Blairgowrie and it was impressively quick from the foundation to up and rendered. Nice little bungalow. 
 

 

I’m delighted with my home, just wish the follow up consultation like heating was easier. On completion I’m sure they explained the whole system in about 7 minutes which is tricky to take in. As I’ve said when electricity was cheap, no need to think about it.

[Redbeard]

Danwood build said: 'DHW?'

 

Domestic Hot Water

[JohnMo]

DHW, Domestic hot water - Heating your cylinder.

[Radian]

Looking at that photo (nice house BTW) what's going on with the lack of snow below the paired roof windows? It seems to have fallen into the gutter rather than being melted off by a thermal bridge in that area, but you never know.

[Thorfun]

2 hours ago, Radian said:

Don't let @SteamyTea catch you dropping your h's

🤣

[Danwood build]

1 hour ago, JohnMo said:

So was your first photo showing the heat pump showing 47 degrees flow temp, on DHW heating, as it does not be match the heating curve?

The photos were at different times. I’m in for next 30 mins if I can supply some more photos. 

[Luke1]

45 minutes ago, Danwood build said:

The photos were at different times. I’m in for next 30 mins if I can supply some more photos. 

 

It was probably for heating. The Nibe system works on 'degree minutes' therefore whilst the curve may say flow at 0C of 32C the heat pump will run until any deficit of degree minutes is brought back to 0.

My heat pump is set to start running at -60DM and in the first few minutes whilst flow temp is lower than the curve it will increase to say -80DM, and then it will lose these for every minute it spends above the curve temp. So if the heat pump is providing water at 42C compared to a curve of 32C it will lose 10DM every minute. Then when it hits 0 it will turn off. This whole situation gets worse when it has to defrost or carry out DHW heating.

 

Frustratingly whilst the heat pump can modulate down, it doesn't seem to get close to the curve and modulate down so that the DM stays stable. My compressor in auto mode appears to run much higher, but for a shorter duration then cut out for a while. I have manually adjusted my compressor curve (in installer settings) to modulate down so it takes longer to catch up the degree minutes, but runs for a much longer duration. I don't have any evidence yet as to which way is more efficient. I suspect the latter may be more efficient as the system doesn't appear to frost up as quickly.

 

The first graph shows the system running with the auto curve in an on / off fashion.

 

The second graph shows the heat pump running at half the power but over a much longer duration.

[Luke1]

2 hours ago, Danwood build said:

 

 

Which controller do you have? Is this an SMO 020?

 

Its odd that you have it running in 'own curve' setting (checking mine it appears these are the exact same defaults that I have) 

I however use the actual graphical curve instead.

 

If you go to heating -> advanced -> curve can you see if you're actually using the own heating curve or the actual curve.

 

This is my current curve:

 

It tells you to set the curve to 0 to use the own curve setting

 

This is what the standard default 'own curve' looks like when you select 0 next to the little thermometer icon.

Edited December 16, 2022 by Luke1