How to Feed Multiple Manifolds

[LA3222]

I am trying to get my head around the whole UVC/ASHP/UFH setup at the minute but before I get into that I have a query about how to splice multiple manifolds together.  In my setup I have UFH on both the ground and first floors, heat will be provided via a buffer vessel, so there will be a manifold upstairs and another on the ground floor. I have seen low loss headers mentioned on a few threads but don't understand their application as such. With my setup what would be the ideal way of connecting the manifolds to the buffer? in parallel with each other or via a low loss header?

 

Thanks

Edited September 23, 2020 by LA3222

[PeterW]

Buffer doesn’t need a low loss header - one or the other. 
 

Depending on the buffer you use (Direct/Indirect) then all you do is a feed from the buffer to each manifold blending and pump set which can either be tee’d or each manifold can have its own feed off the buffer. Returns can be combined to the bottom of the buffer. 
 

Stat on the buffer in series with the time switch controls the ASHP CfH signal. 
 

Some will say you need a zone valve to each manifold but given the mixing valves on a manifold allow very little flow unless they are calling for heat then I don’t bother. 
 

What is heating the DHW/UVC..?

[LA3222]

15 minutes ago, PeterW said:

Buffer doesn’t need a low loss header - one or the other. 
 

Depending on the buffer you use (Direct/Indirect) then all you do is a feed from the buffer to each manifold blending and pump set which can either be tee’d or each manifold can have its own feed off the buffer. Returns can be combined to the bottom of the buffer. 
 

Stat on the buffer in series with the time switch controls the ASHP CfH signal. 
 

Some will say you need a zone valve to each manifold but given the mixing valves on a manifold allow very little flow unless they are calling for heat then I don’t bother. 
 

What is heating the DHW/UVC..?

Thanks for the response Peter, I will have to digest/think about this later and hopefully it will make sense - plumbing seems to be an area that is pickling my brain! I have no issue with everything to the 'right' of the manifolds etc, its the stuff to the left where hot/cold water is supplied to the manifolds that pickle my head!

 

I'm running with an ASHP to three way diverter supplying a buffer and UVC - its a work in progress. Trying to work through all the threads on this subject in order to cobble them all together as a design, I get the gist of it - once I've put pen to paper to draw something I will post it up in order to check I haven't made any fundamental mistakes!

[SuperJohnG]

Always seem confusing all the different views and additions. Would be good to have a guide for all the parts.  

 

I'm a hydraulic engineer and have access to hydrosym for drawing schematics. I'm planning on doing a schematic for my system (UVC/ASHP/UFH). I'm quite happy to draw a standard circuit and share for everyone as a guide. 

[LA3222]

44 minutes ago, SuperJohnG said:

Always seem confusing all the different views and additions. Would be good to have a guide for all the parts.  

 

I'm a hydraulic engineer and have access to hydrosym for drawing schematics. I'm planning on doing a schematic for my system (UVC/ASHP/UFH). I'm quite happy to draw a standard circuit and share for everyone as a guide. 

That would be useful. I started off thinking about SunAmps when I started but have since decided to walk the well trodden route of UVC/ASHP/UFH. There seem to be a lot of threads on this topic but no 'definitive' schematic. I would have thought there would be a simple ASHP --> UVC & UFH layout out there with all component parts listed but that does not seem to be the case. Surely the setup should be fairly standard regardless of house type, size etc  

[Pete]

6 hours ago, LA3222 said:

Thanks for the response Peter, I will have to digest/think about this later and hopefully it will make sense - plumbing seems to be an area that is pickling my brain! I have no issue with everything to the 'right' of the manifolds etc, its the stuff to the left where hot/cold water is supplied to the manifolds that pickle my head!

 

I'm running with an ASHP to three way diverter supplying a buffer and UVC - its a work in progress. Trying to work through all the threads on this subject in order to cobble them all together as a design, I get the gist of it - once I've put pen to paper to draw something I will post it up in order to check I haven't made any fundamental mistakes!

I'm doing the same! Just spoken to a renewables engineer and he was trying to convince me that the new £5000 government grant coming in was a good idea. He said he puts £900 on each job if RHI/MSC is the chosen option.

[Pete]

38 minutes ago, LA3222 said:

That would be useful. I started off thinking about SunAmps when I started but have since decided to walk the well trodden route of UVC/ASHP/UFH. There seem to be a lot of threads on this topic but no 'definitive' schematic. I would have thought there would be a simple ASHP --> UVC & UFH layout out there with all component parts listed but that does not seem to be the case. Surely the setup should be fairly standard regardless of house type, size etc  

There have been a few drawings put on here

,  @joe90did. It is the electrics that I will find the most daunting i think.

[joe90]

43 minutes ago, Pete said:

It is the electrics that I will find the most daunting i think.

And I did, I made my own up in the end with a simple single room stat.

[Pete]

4 minutes ago, joe90 said:

And I did, I made my own up in the end with a simple single room stat.

You know what's coming next pls? Drawing if it is not to much trouble. TIA

[joe90]

It depends on your ASHP as they are all a bit different. My ASHP is set to heat any water to 47’ only. Basically I heated a buffer tank fir UFH and the tank stat on that cylinder kept the temp up. This is heated 24/7 during the heating season. When the room stat calls fir heat it operates the UFH pump to circulate water from the buffer around the floor. A diversion valve is operated by the ASHP to divert hot water to the DHW tank when it’s stat calls for heat. This does mean the buffer (well insulated ) stores hot water fir UFH all the time but it saves waiting for the ASHP to get up to temp before it starts heating. Some here don’t have a buffer tank fir UFH. (Not sure I would if I did it again). I did buy an expensive controller which means that things such as the heat curve can be changed but frankly it was so complicated I never use it. I may go E7 in the future which simply means installing a timer so the ASHP only comes on during cheap hours (and an override switch fir emergencies).

[Gav_P]

23 minutes ago, joe90 said:

I did buy an expensive controller which means that things such as the heat curve can be changed but frankly it was so complicated I never use it.

Fancy getting rid of it?? I could give it a home ?

[joe90]

9 minutes ago, Gav_P said:

Fancy getting rid of it?? I could give it a home ?

I do use it to monitor the state of the ASHP , even @Jeremy Harris had difficulty working his (same as mine).

[Gav_P]

1 hour ago, joe90 said:

even @Jeremy Harris had difficulty working his

... I don’t stand a chance then!!! ?

[LA3222]

Right, after a little bit of reading I have a few questions that I'm hoping someone can clear up for me if they would be so kind @PeterW or @Nickfromwales?

 

Peter, you mention indirect/direct buffer and that has got me to thinking which you would use and why.

 

What I think I understand:

 

Both direct and indirect have a coil in them which the ASHP fluid travels through in order to dump heat into the buffer.

 

Direct has a coil in, which is what the fluid within the UFH system travels through in order to extract heat out from the buffer.

 

Indirect has no coil, so the fluid within the buffer is what travels through the UFH system.

 

 

So, regarding putting heat into the buffer it makes no odds - it is the same for both.

 

Taking heat out:

 

Indirect - separate coils, bad for space in the buffer? A single shared coil, so the flow and return would need to be tee'd together?

 

Direct - separate feeds to each manifold with the returns tee'd in? Each manifold draws heat seperately as required direct from the buffer.

 

Question: which is the best way to skin the cat so to speak in terms of feeding two manifolds from a single buffer and why? 

 

My best guess - direct would be better as each manifold can draw separately from the buffer? Wheras indirect they would be sharing a coil?

 

Thanks for any advice you can give.

Edited September 23, 2020 by LA3222

[Nickfromwales]

With 2 floors of heating you are correct, and I would not put that much through a coil. The buffer needs to be 'man enough' to accept and discharge the required heat influx / outputs as required at any one time, so sizing will be important. Small heat source = bigger buffer and vice versa.

[PeterW]

Noooo...

 

Indirect has a single coil that rhe ASHP is connected to. It hydraulically separates the UFH from the ASHP so you don’t need antifreeze in the UFH etc. 
 

Direct is basically a 60-90 litre cylinder with lots of connections - fluid from the ASHP flows through anything connected, including into the UFH loops. 

[Nickfromwales]

Buffers can have a coil, so sorry if wires crossed here. @LA3222 have you seen a particular buffer that you are referencing here? The Jaspi store is one such beast IIRC. http://www.northmangroup.co.uk/Ultra500.html

[LA3222]

Ah right, @PeterW so if a coil is in it at all then its called 'indirect' and no coils at all is 'direct'.

 

I was thinking that the direct refers to the UFH side having no coil but it is both sides.

 

So if I understand it right now, a buffer tank with a coil in for the ASHP but no coil for the UFH side is still an Indirect buffer?

 

I dont have anything specific in mind yet @Nickfromwales, I'm trying to understand the 'how' of things at the minute.

 

So, i don't want the ASHP antifreeze running through the entire UFH system which means an Indirect buffer is the weapon of choice and Nick mentions not wanting to draw two supplies through one coil, so each manifold will need a tapping direct onto the buffer to circulate that water through the UFH system?

 

TLDR: More than one manifold, use an Indirect buffer and have each manifold flow tapping on the buffer tank, tee the returns together then onto the buffer tank.

 

I hope I've got this tight now?

Edited September 23, 2020 by LA3222

[joe90]

My buffer is indirect, as said above ASHP connects to coil (like DHW tank) and antifreeze not required in UFH. My buffer gives me a hot water source immediately rather than wait for ASHP to get up to temp.