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Army Housing- Ecodan with UFH efficiency?

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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

Hello everyone!

New to the forum, not new to having an ASHP but new to the understanding of running it. 
Jump down to system part if you don’t want to read a story haha! 🤣 

 
This recent winter snap has caused me to knuckle down on the heating system, the actual efficiency and the understanding of using it.

Giving up on contracted engineers coming in to say yeah you got some heat it’s fine, with no regard to efficiency or whole house system working properly. 
So I have a few questions that I hope you guys/gals will be able to help me with. 

Firstly I moved into the army pad in ‘17, anyone that doesn’t know how a ‘March in’ works:

You get shown round by an accommodation officer (this was CarillionAmey…) and they show you the whole house ins and outs, give you a home pack(manuals), a damage report (any existing damage, if any, we can report straight away and on our March out you don’t get charged) etc.

Though when it came to the heating system it was the classic- Show the ASHP, show the boiler and said leave it all On and don’t touch it and just use the thermostats around the house.

Not knowing what the sketch with HPs and UFH is, meant for first 3 years I turned off the heating completely during spring/summer/autumn. Timing the hot water for night period. Switching the heating on a timed basis for when “Winter is Coming.” Back in the days when leccy was cheaper (was on Octopus Agile before wholesale shot and had to jump to Flexible).

 

System- Ecodan 5kw ASHP (2nd pump, more on that later)

Connected to FTC2 (old and bold) and a Danfoss Timer panel (no Danfoss master Thermostat??)

UFH from Warmafloor (god knows piping sizes!) with 2x 6 zone manifolds. 
Stats in every room!

House- End Terrace- 112 m2 built in 2012. All electric (no gas plumbing in sight)

EPC grade B with energy rated at 80kWh/m2 (out of date as this year though)

3 floors -Garage on ground floor with entrance hallway and utility room (boiler, pumps, controller etc)
1st floor- UFH manifold, raised back garden where the Ecodan ASHP is located. 

2nd floor- 2nd UFH manifold

This whole estate (225-250 houses) that was built for us was all built 3/4bed houses all with UFH and ASHP (contractors rolling in it! Along with the owner that signed the RHI)

Fair to say usually families come and go dependent on the serving partners assignments. So being here 5 years and going to be for the foreseeable is brilliant. Though the estate is now in disarray, many houses are now “condemned” due to…. the heating systems. We don’t get shown by people that understand the heating system how to actually work it properly so it comes as no surprise a lot are now condemned. 

We had a couple heating problems a year and half ago but luckily was in summer and was affecting the Hot water. Engineers deemed it was the ASHP and so changed it for like for like brand new Ecodan 5kw (yes free of charge)

Recent cold snap has made me dig into YouTube and Google about UFH and ASHPs, nearly watched every HeatGeek video so learned a lot in past week, but after paying £97 and £95 past 2 weeks.
£305 for mid Nov’-mid Dec’.
I know current climate means it’s tough but surely having a fairly modern home, decent insulation with UFH and HP means it should be fairly decent?

Current situation- Heating works ok on ground and 1st floor with on 0.8 bar (can’t increase with u pipe for some reason).

Heating does not work effectively on top floor, can’t heat above 16/17oC at 1.6bar and flow rates in manifold disappear soon as one stat downstairs calls for heat.

Recently- After watching many HeatGeeks made me pluck up courage to touch the boiler more than simply setting timers. I actually had to ‘hack’ FTC2 because Army/Contractors don’t want us fiddling the system. It was on Locked mode, nothing a good google of Ecodan manuals can’t fix 😎 

Settings- I now have HW to heat 0130-0300hrs @ 47oC (down from 58oC) we generally have a big use so negates the Legionnaire risk.

Heating I have learned about Weather Compensating, and know the system only allows for this. Albeit a very basic Min/Max WC.

I have now reduced the heating to -2oC/40oC with 15oC/30oC.

It was at -3oC/48oC with 15oC/35oC..

I know understand HP with UFH is such a delicate system and is best run low and slow.

Questions- How much efficiency should I be really be expecting, am I right to say the system set up is bad and probably the installation is poor? And any little efficiency tips?

Best way to run the heating without having advanced settings that most people seem to have nowadays? 
Max out stats and use WC till house is comfy?

How can I improve the flow to top floor and raise flow rates in manifold?
When top floor is calling and 2nd floor isn’t, the most flow in seems to only be 2L/min shared out 

 

Lastly, I know it’s Winter but how the heck do you get the Cooling to switch on FTC2. In summer, the house is disgustingly hot.

 

Any questions, thanks for any help everyone, and glad I found this little forum!

Cal


   
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(@derek-m)
Illustrious Member Moderator
14001 kWhs
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Joined: 3 years ago
Posts: 4203
 

Hi Cal,

Welcome to the forum. It would appear that you have already made a good start by turning up the thermostats and adjusting the WC curve and DHW setting.

Without being able to see the layout of your system I will have to make a few assumptions, which you can correct as necessary.

I assume that each of your UFH zones will have a water pump and mixing valve, which will be controlled by the thermostats. Do you have any form of buffer tank or low loss header between the heat pump and the UFH manifolds?

I'm not an expert on UFH but I do believe that the flow through the different pipe loops can be set at the manifolds. For maximum efficiency on a heat pump system it is best to operate with the lowest possible Leaving Water Temperature (LWT), but you also need to ensure that there is a good flow water around the system. That way the heat energy produced by the heat pump gets distributed around the system, so if any flow rates appear to be low then it may be useful to increase them. Obviously before making any changes make a note of all the original settings and only make one adjustment at a time and observe the result.

From the point of view of losing heating on the second floor when the first floor is operating, it may pay to monitor the temperatures on the various pipes to try to assess where the water is flowing under different operating conditions.

 


   
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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

Hi Derek

Thanks! Yeah did not feel right to turn up stats to turn down system 😅

I can take some photos of the layout in the morning, I guess that will help you and other members that know a lot more than I do, but hey we all start somewhere haha. 

For the water pump and mixing valves per zone I’m unsure. But buffer tank/LLH I’m sure there is down in the utility. There is 3 water pumps down there too, which I feel is strange. Most set ups online have a pump between the Flow/Returns of the manifold and all mine are down on the ground floor… 😅

 

Yeah that sounds familiar, so tried to slightly adjust flow on manifold upstairs but they don’t react when down stairs is operating. 
The part about LWT is new though, I’ll need to read up about that.

Ahh yeah that’s a good idea to try see where flow is going, thanks! One engineer said, water goes to path of least resistance (correct) so can’t be helped (really?) I.E can’t heat upstairs while downstairs operates… surely I can somehow 😂

 


   
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(@derek-m)
Illustrious Member Moderator
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Joined: 3 years ago
Posts: 4203
 

Hi Cal,

The LWT is the temperature of the water leaving the heat pump, the RWT is the temperature of the water being returned to the heat pump. Simples.

There is normally a 5C difference (Delta T) between LWT and RWT when the heat pump is working normally.

As you may have read in other posts, a buffer tank or low loss header can be a source of inefficiency in a heat pump system. I can explain in detail later.

This post was modified 1 year ago 2 times by Derek M

   
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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

Ahh yeah got you, learned about the Delta T but didn’t know the LWT and RWT names but makes sense now.

 

Yeah have heard/read some things about them but like most the system I’m at baby steps 😂 I think there’s one but not sure if it’s just expansion vessels. 
I’ve taken photos of the system, and counted 8 stats to the 12 zones. 

BEC81568 557E 48FE A9F1 03486CD4797E
167D1226 5A25 4A5B 9B76 5EC52A075051
5E4F46D8 292F 4E7F AEAE 179485CDCEFB
909BC99A 2D9F 45F3 86BA 408D4CB5FC50

Is the mounted white tank maybe a buffer or LLH?

B44D0945 D0D5 4877 A94C 7D7D2E967F1D
1922444B 33D6 4954 B593 98F4B2B2218F

1st Floor manifold- living room (1) calling and was flowing at 2L/m

3399EDBB 8E80 4A6C AB08 7551F168B75B
6131570B B24B 4BE9 A196 F04F3A01CAD3
434A6006 4BDA 414B 85C1 C61704E9B3FE

 2nd floor manifold- bedroom 3 calling with 0L/m as per issue stated in OP. 

ADEE845F 7838 46CF 8046 ECA8E6DA8058
24AC59DB A02D 4185 A24F 5399A3BD9FBA
2E580039 6540 43F9 819F DC083882C39B

Is it not meant to be level? And Pipes fully insulated?


   
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(@batalto)
Famed Member Member
3655 kWhs
Joined: 3 years ago
Posts: 1091
 

@calzo21 if the upstairs is cold - have you tried adjusting the mixing value to add less colder water in?

12kW Midea ASHP - 8.4kw solar - 29kWh batteries
262m2 house in Hampshire
Current weather compensation: 47@-2 and 31@17
My current performance can be found - HERE
Heat pump calculator spreadsheet - HERE


   
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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

@batalto Rgr having a look, is that the green valve circled here? It’s currently set on 41oC even though flow temp is no where near haha

D84E38B8 5E15 4EEA ACA2 1F3E64009780

   
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(@derek-m)
Illustrious Member Moderator
14001 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4203
 

Posted by: @calzo21

@batalto Rgr having a look, is that the green valve circled here? It’s currently set on 41oC even though flow temp is no where near haha

D84E38B8 5E15 4EEA ACA2 1F3E64009780

If you can show a closeup of the nameplate on any equipment it will make it much easier to identify.

 


   
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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

@derek-m No problem, I posted lots of photos of the system after your last reply Derek but it’s still waiting moderation. 

Here’s a close up of what I think is the mixing valve for 2nd floor manifold, there’s also one down in the utility room I’m guessing for the 1st floor manifold?

0301085E C898 4142 B804 0296BB063E19

   
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(@derek-m)
Illustrious Member Moderator
14001 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4203
 

Posted by: @calzo21

@derek-m No problem, I posted lots of photos of the system after your last reply Derek but it’s still waiting moderation. 

Here’s a close up of what I think is the mixing valve for 2nd floor manifold, there’s also one down in the utility room I’m guessing for the 1st floor manifold?

0301085E C898 4142 B804 0296BB063E19

Hi Cal,

Yes, I found all the photo's and have now approved.

The above is a differential pressure valve, though I am still trying to figure out what purpose it serves. Is there just one of these valves on the first floor manifold? If so, then its purpose could be to balance the flow rate to both the first and second floor manifolds.

So that I am not trying to 'teach my Granny to suck eggs', how knowledgeable are you when it comes to heating systems?

 


   
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(@calzo21)
Eminent Member Member
94 kWhs
Joined: 2 years ago
Posts: 13
Topic starter  

@derek-m This one is connected to the 2nd floor manifold, and there’s another down by the boiler on ground floor as pictured.

65C4D053 88B9 4BC2 B481 C50C034ECF54

I’m going to say I’ve got basic knowledge, like said last night I’ve only started knuckling down on trying to understand the whole system and that’s 5 years with it 😅 don’t worry about me sucking eggs I’m used to it being in the Army 😂


   
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(@derek-m)
Illustrious Member Moderator
14001 kWhs
Veteran Expert
Joined: 3 years ago
Posts: 4203
 

Posted by: @calzo21

@derek-m This one is connected to the 2nd floor manifold, and there’s another down by the boiler on ground floor as pictured.

65C4D053 88B9 4BC2 B481 C50C034ECF54

I’m going to say I’ve got basic knowledge, like said last night I’ve only started knuckling down on trying to understand the whole system and that’s 5 years with it 😅 don’t worry about me sucking eggs I’m used to it being in the Army 😂

Okay, I will describe how I think that your system should operate for best efficiency, and then you can check around the system and see if it is working like that.

The heat pump is a heat energy producer, which gets some of its energy from the electrical supply, but the majority of the energy from the outside air. The heat pump draws air in at the rear and one side, and pushes cooler air out at the front. It is therefore important that there is a constant supply of fresh air that does not include the cooler air coming out at the front.

The heat energy is transported into your home via two pipes, the flow and return. These should be well insulated to prevent heat loss.

A heat pump system can provide both central heating (CH) and DHW, but normally does not heat both at the same time. In most instances the system is set to give priority to heating DHW in preference to CH. In your system you will notice some valves with white rectangular boxes on top, these are the control valves that divert the water flow from the heat pump to either the hot water cylinder or the heating system. The valve feeding the hot water cylinder should not be open at the same time as the one for the CH. These valves are easy to test by setting your controller to provide DHW heating and then switching it off.

The upper manifold for the UFH is the warm water supply, on which is installed the 6 flow regulators which have the red caps. The lower manifold for the UFH heating contains the 6 solenoid valves, which I assume are controlled by individual thermostats in the relevant rooms.

If you can provide photo's of the other items of equipment, pumps, valves etc. I will try to figure out what they are doing.

 


   
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