U/floor manifold

[southcoastboile]

Hello.

Im installing a new u/floor heating system, nu heat low pro max.

Wondering if anyone can help me or advise in the best position for the pump module.

its a bungalow with 2 separate manifolds, one located under the boiler and one in the hallway cupboard.

the pump module which has the TRV type temperature regulator and mixing valve/ pump comes as one complete unit. I know normally this would connect directly to the manifold but seeing as there are 2 manifolds in separate locations that would be impossible.

im thinking of running the flow and returns into the loft and having the pump module half way between both manifolds, then drop down to both manifolds from there.

can anyone see any issues with this or is there a better way of doing it?


i can attach some pictures if it helps.

Thanks in advance!

 

[tolly]

If you have to have two separate manifolds I would just get two pumps and blending valve sets

 

[southcoastboile]

Thanks tolly. Nu heat design the system for you and only supplied one. They didn't show a location for the pump module though.

Why would it be beneficial to have 2 pumps and Blending valves?

 

[ShaunCorbs]

if nu heat have designed it for you ring them up if not on plans or they havent sent you one by mistake

 

[tolly]

if nu heat have designed it for you ring them up if not on plans or they havent sent you one by mistake

I reckon they've made a mistake and havnt sent a second pump control pack, is it a fairly large bungalow? would one large manifold in a central position not work?

I've never heard of someone designing it like that before for domestic with one pump and blending valve then splitting off to two separate manifolds.

 

[ShaunCorbs]

I reckon they've made a mistake and havnt sent a second pump control pack, is it a fairly large bungalow? would one large manifold in a central position not work?

I've never heard of someone designing it like that before for domestic with one pump and blending valve then splitting off to two separate manifolds.

me nether by the time the flow temp has got to the manifold prob dropped 5 dc and dont think one pump would do two equally

 

[tolly]

me nether by the time the flow temp has got to the manifold prob dropped 5 dc and dont think one pump would do two equally

I can picture some poor bloke teeing into flow inbetween TMV/pump and manifold for a towel rail aswell in the future not knowing any better thinking it was just CH pipework

 

[Unregistered]

Thanks for all the advice. I will ring Nu heat and see what they say.

 

[southcoastboile]

Not sure if these attachments have worked. It shows the lay out of the system.

They have definitely got the pipe work lengths wrong. Manifold one is located under the boiler in the kitchen which feeds kitchen/lounge and manifold 2 is located in a cupboard central to the house. This feeds bedroom, hallway, bathroom and office.
They have got the pipe run lengths to the manifolds the wrong way around but that's not a big deal.
It says it should be 1m to pump module from boiler flow, then 1m to manifold one and 10m to manifold 2.
I said to him that the temperature drop will be greater to manifold 2 as it's 10m away and he didn't think this would be a Concern. When I asked him if it would be better to have another manifold he said they done normally do it like that because it's more expensive.

I told him that I would rather have had the option and that I want it done correctly if I'm going to do it. The system is already costing £6k! (Inc screed)For that I would expect it to be correctly designed at least.
Maybe I'm being to fussy but if it did drop say 4 degrees through loss of heat on pipe work run I would say that's significant on an u/floor system.
Not sure what you guys think?
I'm swaying to words buying another manifold but I don't think it's fair that a system that expansive was not designed with this in mind to start with?

 

[ShaunCorbs]

Buy another manifold and to it properly,

and bin the design except for under floor layout (pipe runs/places)

 

[Worcester]

Buy another manifold and to it properly,

and bin the design except for under floor layout (pipe runs/places)

Even then would be better if done as snail layout rather than serpentine... Aslo one draing says 2 port and 4 port manifold yet pipe layout shows 7 loops on one and 9 on the other...

However pays ya money makes ya choice - go back to Nu-heat that's what you paid them for.....

What's your heat source? If it's a heat pump, it should be installed differently anyway..

 

[southcoastboile]

Thanks Shaun.
Yeah that's what im thinking.
Also. The manifold and pump module won't be able to fit in the cupboard together. The pump module is quite large so they would have to both be located in the loft space and drop down by about 1.5m in copper before connecting to the manifolds. I don't really have much choice in that but do you think that would be an issue?

 

[Chalked]

I reckon they've made a mistake and havnt sent a second pump control pack, is it a fairly large bungalow? would one large manifold in a central position not work?

I've never heard of someone designing it like that before for domestic with one pump and blending valve then splitting off to two separate manifolds.

Quite a few larger systems have one temp mixer and multiple manifolds. All fed of one or multiple pumps located before the mixing station.

 

[Worcester]

So long as the distribution pipe work is insulated it should be fine, no different from our heat pump installations, just be aware that the flow rate may well be higher due to the lower delta T across the floor circuits, (usually made up by mixing return with flow when done at the manifold) deltaT of 5 needs twice the flow of a deltaT of 10 for the same heat output.

Higher flow rate, smaller pipes = greater head loss - do the calcs ( or get nu-heat to do them for you )

 

[southcoastboile]

Thanks Worcester. A lot of that is over my head to be honest. It's running from a combi boiler.
Now I'm getting worried that the manifold is not correct for the pipe layouts shown in the drawing?

 

[southcoastboile]

Just figured that part out. Some of the ports have several outlets going to them with some adaptors

 

[Worcester]

Just figured that part out. Some of the ports have several outlets going to them with some adaptors

WT****** Why do that?, Never seen it done that way... We always run each loop to it's own port on the manifold, that way you can set the correct flow for each loop.

Only reason I can see for doing it that way is for them to make more profit by skimping on the specification. (smaller manifold, less actuators, cheap 2 into 1 connectors), I appreciate it is the lo-pro product, even so.. - Ask them to justify that approach.

Little job, 10 loops first floor (beds and baths) 6 towel rails and 5 rads (2nd floor), this section will have 2 circulation pumps, one for the 10 port manifold and one for the 6+5 (downstairs has 2 more manifolds and 2 more circulation pumps) each room controlled by Heatmiser Neo (19 room controllers and 37 actuators)

 

[Chalked]

WT****** Why do that?, Never seen it done that way... We always run each loop to it's own port on the manifold, that way you can set the correct flow for each loop.

Only reason I can see for doing it that way is for them to make more profit by skimping on the specification.

Just a guess. But I think that when fitting the overlay from nu heat the pipes are 12 mm. Each port is then doubled up to provide more than one flow and return.

 

[southcoastboile]

Do you think it's a bad design then? The ones that are doubled up are for the same room I think so the flow Rate for bedroom 1 has 4 pipe runs for example but they all go into one port so the flow rate for that room could be controlled separately?
The tuning is 10mm.
Does that seem like a bad idea? I would assume it would be better as it would heat the floor more quickly with several flow and returns to one area rather than just one flow and return?