Connecting radiators to UFH Manifold?

[Smarts67]

Hi Everyone
I wasn’t sure whether to post this in here or UFH but hopefully I’m posting this in the correct group.

I’m in the throes of a full renovation and am currently designing the central heating system, I’m installing radiators (11 or 12 in total) and am going to run each rad from its own loop on a manifold, each rad will have a wall mounted thermostat and actuator valve on the manifold all connected to a wiring centre so each rad is individually controllable.

I’ve done this same setup in a previous property with a 4 port manifold and it worked just great using just the circulation pump in the boiler, I wondering this time if I’m going to need an additional pump at the manifold with the increased number of rads, but I thought I’d read somewhere that 2 pumps can work against each other when on the same loop and cause problems
If that’s the case I did wonder if I just used the same setup as UFH with a pump and a blend valve as I know that doesn’t cause an issue, I’ll be over sizing the rads anyway to future proof for an ASHP should I ever go down that route, so will be running at a lower temp.

I was wondering if anyone had any experiences of a similar setup or had any additional thoughts

Thanks in advance

Martin

 

[ShaunCorbs]

You shouldn’t do aslong as you place the manifold centrally or have a separate manifold for up and down stairs

 

[IND_Nick]

We do a lot of UFH ground floor and radiators upstairs, both on separate manifolds fed by the boilers pump. Never had any problems and they work great, often I pipe a towel radiator in as a bypass option before the upstairs manifold. Works really well with a cylinder and hot water priority setup, that way you can set CH flow to 50 ish.

 

[Smarts67]

Shaun, Nic thanks for you replies
I didn’t really know anything about HWP, I had a read and see it’s boiler model dependant so I’ll add that to the spec for the new boiler
With both of you saying use a separate manifold upstairs and downstairs is there a reason for that? I won’t be putting any pipework under the floor on the ground floor, I was going to put a single manifold on the first floor landing and all pipe work will run under the first floor and drop down the stud walls to rads on the ground floor and tails straight out to the first floor, does that seem workable?

 

[ShaunCorbs]

Yes you can have one manifold if you want for that the issue would be air or long pipe runs

 

[IND_Nick]

We often use two manifolds as it allows you to set different TMV temperatures for UFH and radiators, just allowing more control.
If you are making a list also consider weather compensation as this can work well with low temp heating systems. And remember to insulate as much as possible, if you can stop the heat escaping it doesn't need more input.

 

[Smarts67]

We often use two manifolds as it allows you to set different TMV temperatures for UFH and radiators, just allowing more control.
If you are making a list also consider weather compensation as this can work well with low temp heating systems. And remember to insulate as much as possible, if you can stop the heat escaping it doesn't need more input.

Yes I’m insulating the crap out of the place, i ve added weather compensation to the list thanks. So when you do a dual manifold systems you use TMV’s but not a separate pump just rely on the boiler circulating pump, I know it would be dependant on the size of system but our is a fairly small footprint longest feed would probably 7m from the manifold majority 5m or under and all rads no ufh

 

[IND_Nick]

Yes I’m insulating the crap out of the place, i ve added weather compensation to the list thanks. So when you do a dual manifold systems you use TMV’s but not a separate pump just rely on the boiler circulating pump, I know it would be dependant on the size of system but our is a fairly small footprint longest feed would probably 7m from the manifold majority 5m or under and all rads no ufh

Each manifold will have it's own pump and TMV. Boiler pump for cylinder and supplying manifolds.
If it is just rads, so no TMV, you could probably get away with just the boiler circulator if it's close to manifold and only 11 rads.