Help us understand how this UFH system works please!

[whatsthenews]

I haven't disappeared yet, but please confirm we are talking about Friars Wharf, otherwise I'm going off at a tangent. No it's not running off your meter.

Here is a learned dissertation that just happens to mention how the Friars Wharf system, in general terms, is supposed to work, see page 113 figure 30 and beyond:

https://www.escholar.manchester.ac.uk/api/datastream?publicationPid=uk-ac-man-scw:224721&datastreamId=FULL-TEXT.PDF

Doesn't really help us answer your burning questions.

It appears the bank of 8 air source heat pumps run from 3-phase 440v. I don't imagine they would try to measure the electricity consumed by each flat, only the total for the building per month/quarter etc. It is the purpose of the energy meter in each flat to determine, on the basis of the flow through the water pipe, the incoming water temperature, and probably the outgoing water temperature, what the kWh equivalent of energy used is. They then hopefully attribute the contribution of each flat according to the energy meter readings in proportion to the total consumption, so each pays their 'share'. No doubt with an admin/management fee on top. But still according to a transparent rationale that flat owners are aware of.
I believe the heat output of the heat pumps should be roughly 3 times the electricity they use.
So assuming the meters in the flats are actually accurate, the following things should be true:
1) adding up all the flat meter readings for a given period and dividing by 3 should total approx the electricity bill for the building for that period (actually this is the way to find out the exact proprtion)
2) dividing by 3 the unit price per kWh for the heat pump supply, and multiplying by the number of units used by a flat, should be the bill for that flat, and adding all the flat's contributions should pay the overall bill.
Maybe someone got their sums wrong, not all the heat pumps were working properly, not all the kWh meters were working properly, or some other part of Murphy's Law came into play, and the landlord was out of pocket.
Well that's my theory!
I hope they know what their doing with their bills now. I would hope the heating charges would be less than half the 'equivalent normal' electricity bill would be.

There should be information about this in the Management Pack, Handbook or "Safety Manual", or whatever they've chosen to call it, or the lease, or other documentation for the property. Normally you sign to agree to the terms.

Nice flats!

Yes, we're talking about Friars Wharf, and I really appreciate your input Basher. I didn't think about looking for academic papers. The management company , Zenith, are Manchester based

Now in possession of a meter reading at least (although knowing what we now know about the ASHP's, I'm a little reluctant to accept their reading. Would rather have eyes on the meter myself.)
.
I agree with your calculations and the presence of the heat meter makes sense now, although we've never been told that we will need to submit any readings or that anyone will need access to look at it We are keeping a check on it.
Is it correct to say that in the coldest months (now!) the COP will be lower than 3?
My parents has a house with an ASHP (air to air) in the US when we lived there. Generally although the winters were much shorter and sunnier, we had colder temps than here and they had an emergency back up "heater" that came on automatically when the temp went down to below about -4c and the pump couldn't raise the air temp' sufficiently to reach the set temp'.
We don't have an info pack nor any instructions for anything.
We've emailed the letting agent and told them we think the UFH runs off communal ASHP and asked how it's billed.
Thanks again!🙂

 

[whatsthenews]

Whatsthenews, I've just discovered another thread on this forum on the same system, from 2010!

How can I turn my underfloor heating on? | Plumbing Jobs | The Job-board | Plumbers Forums

Find How can I turn my underfloor heating on? Advice and Help. How-to How can I turn my underfloor heating on? in the Plumbing Jobs | The Job-board advice boards on Plumbers Talk | Plumbing Advice | Plumbing Forum - Professional and DIY Plumbers and Bathroom Fitters Forum. How can I turn my...

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Just had a reply to our email. Apparently the landlord pays for the UFH in with the service charges. I'll take a loom at the thread.
Thanks again for helping us with the conundrum.

 

[whatsthenews]

Just had a reply to our email. Apparently the landlord pays for the UFH in with the service charges. I'll take a loom at the thread.
Thanks again for helping us with the conundrum.

Whatsthenews, I've just discovered another thread on this forum on the same system, from 2010!

How can I turn my underfloor heating on? | Plumbing Jobs | The Job-board | Plumbers Forums

Find How can I turn my underfloor heating on? Advice and Help. How-to How can I turn my underfloor heating on? in the Plumbing Jobs | The Job-board advice boards on Plumbers Talk | Plumbing Advice | Plumbing Forum - Professional and DIY Plumbers and Bathroom Fitters Forum. How can I turn my...

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yes, that's the same guy who posted in 2011 about the charges for the UFH (I posted the link a couple of posts ago). Doesn't sound like anyone knew what they were doing.
Sadly I can't see his photos. One guy states that the pump's in the wrong place!

 

[Basher]

Now in possession of a meter reading at least

i'm assuming you're talking here about the electricity supply to the flat, for hot water etc. Thats good news.
I hope the reading tallies reasonably with the last estimated bill! But of course that reading is nothing to do with the ASHP's and the UFH consumption.

As far as the UFH is concerned, the Rossweiner kWh meter should communicate readings back to a central unit. I believe all the flats readings would be logged centrally, or at least that would have been the case when the system was installed, probably integrated with some software that looks like nobody knew much about. Hopefully after all this time it's being done properly!

Thanks for the update. Hope things go smoothly at the flat.

 

[whatsthenews]

View attachment 47513
The big guns

 

[whatsthenews]

i'm assuming you're talking here about the electricity supply to the flat, for hot water etc. Thats good news.
I hope the reading tallies reasonably with the last estimated bill! But of course that reading is nothing to do with the ASHP's and the UFH consumption.

As far as the UFH is concerned, the Rossweiner kWh meter should communicate readings back to a central unit. I believe all the flats readings would be logged centrally, or at least that would have been the case when the system was installed, probably integrated with some software that looks like nobody knew much about. Hopefully after all this time it's being done properly!

Thanks for the update. Hope things go smoothly at the flat.

yes , the meter for the immersion heater.
Not very bothered about how they calculate how much to charge for the UFH as we don't have to pay it.
It's a nice flat. Spacious and bright and a nice, if somewhat gritty, view over the river and a boat yard from living area and balcony. Lots to watch and will be even more in the Summer and if we ever get out of this COVID malarkey.