Underfloor Heating and Radiators combined.

[Nordio]

I want to install radiators and ufh on the same floor with a compensator controller with 1 mixing valve with room influence and outdoor reset supplying both the rads and ufh combined.
What I was thinking was sizing the rads for a heat pump install. Thats 50 flow and 40 return.
Underfloor loops adjusted for 10c drop also.
Then set the compensator curve to suit the ufh. Though perhaps a bit steeper.
Zone valve on the ufh so that I can operate it independantly and also to shut the flow off on a signal from a floor sensor when the floor temperarture in an occupied area reaches 29c to prevent floor over heat.
What do the experts think? Has this ever been done? What problems am I likely to encounter?
Thanks.

 

[Nordio]

Anyone?
This is the controller....
http://www.syxthsense.com/product/product_pdf/CT2.40-PDS2-H.pdf

Any thoughts on how the rads and ufh will perform together on a single flow set point acheived by the controller?
Thanks for reading.

 

[ManchesterGas]

I think if we knew why then we would be able to advise properly. Why not just use the UFH only?

 

[Nordio]

The ufh will be used on its own. As will the radiator zone. But also used together and all fed from a single mixing valve.
Why?
Well why not?

 

[Gray0689]

You only need to mix the underfloor circuits not the rads they will branch off before the mixing valve and also
Rads will need to be suitably oversized to compensate for the lesser working temp from a heat pump
Best to get someone in to advise you on what you can do
Why that weather compensation unit
You would be better getting the full
Set up from the one company look
At uponor they have some really good set ups now and mostly all wireless now

 

[ManchesterGas]

I was reading it as the rads and UFH were in the same room. as above, tee off and zone rads seperate before the mixing valve, both zones will have their own call for heat.

 

[ecowarm]

You can have the underfloor and rads after the mixing valve and as you say oversized to take into account lower flow temp.
That controller needs to be mounted in a panel, have you looked at other makes? I have had dealings with these people MODVLVS MIXING PACK & KANMOR 360e > Radiant Control Ltd. found them very helpfull on the technical side.

 

[Gray0689]

You can have the underfloor and rads after the mixing valve and as you say oversized to take into account lower flow temp.
That controller needs to be mounted in a panel, have you looked at other makes? I have had dealings with these people MODVLVS MIXING PACK & KANMOR 360e > Radiant Control Ltd. found them very helpfull on the technical side.

Yes you can have it after mixing valve but IMHO it's better to try and get as much heat in rads as you can so I'd go before mixing valve

 

[MattWeth]

What type of HP are you using?
It'll depend on the manufacturer and specs but 50C flow temp is pushing it for a standard (not multistage) heat pump - even if it's (just) within the operating range, you'll find efficiency and COP will suffer badly unless you size for the recommended peak efficiency.

 

[ecowarm]

I dont think the OP is using an Heat pump, just oversizing the rads for lower temp flow.
I maybe wrong though.
Nordio, Have you sourced your 3 or 4 port mixer/ accuator and weather comp. controller? PM me and I can point you in the right direction. Less than £200 for it all.

 

[Nordio]

You can have the underfloor and rads after the mixing valve and as you say oversized to take into account lower flow temp

Thanks. Have you ever done it or do you know any companies who have?
Its not convention I gather.
Do kanmor have any info on the subject of a single primary flow supplying both rads and ufh together at the same temperature?

 

[Gray0689]

Thanks. Have you ever done it or do you know any companies who have?
Its not convention I gather.
Do kanmor have any info on the subject of a single primary flow supplying both rads and ufh together at the same temperature?

I don't really see why you would want to do it if your not installing a heat pump
Or do you just like big radiators lol

 

[ecowarm]

Thanks. Have you ever done it or do you know any companies who have?
Its not convention I gather.
Do kanmor have any info on the subject of a single primary flow supplying both rads and ufh together at the same temperature?

I have worked on systems with the Kanmor controller supplying ufh and rads with weather comp, when set up correctly it worked well. I 'm looking to install a mixer with weather comp conroller at home for radiators only (no ufh) supplied by a wood burner. I am waiting for the 4 port valve, acctuator and controller incl. sensors and outdoor sensor to come, just ordered today. The 4 port valve keeps the return temp above 45c for the wood burner and recirculates some of the c/h water. Got the lot for less than £180 inc vat and delivery. The kanmor is more than that on its own.

 

[Nordio]

I have worked on systems with the Kanmor controller supplying ufh and rads with weather comp

Thanks.
So no other mixing devices lowering the temp to the ufh? All supplied direct from a single source.
Do you recall how the rads were sized? Pretty large I suspect.

Gray..
No heat pump. Rads sized for heat pump so that the ufh flow is supplied into the rads also.

 

[Gray0689]

Yes I understand what you want to do just can't really see why you would want to do it???
Am I missing something here??

 

[Nordio]

I want to keep things simple.
Ideally supply the standard radiator temperature (70-50 I think) direct to the underfloor heating. But it will end up cooking the floors and doing damage.

So I'm thinking right size the rads for lower temps so that they will accept ufh flow and vice versa. So the ufh will less likely to be harmed by a high flow temperature.
Except when the outside temp drops to say -10 and the compensator curve might ask for a 65c flow into the heating system.

But the screed sensor will protect the floor if this happens. Do you get my drift?

 

[MattWeth]

just can't really see why you would want to do it???

Me too...

Why do you want a low temp flow to your rads? Fine for the UFH but you're just throwing money away on big expensive low temp rads (and running your whole system inefficiently).

Unless you think you might fit a HP in the future? (In which case you'll want to size your emitters for a lower temp than 50C).

 

[MattWeth]

I want to keep things simple.
Ideally supply the standard radiator temperature (70-50 I think) direct to the underfloor heating. But it will end up cooking the floors and doing damage.

So I'm thinking right size the rads for lower temps so that they will accept ufh flow and vice versa. So the ufh will less likely to be harmed by a high flow temperature.
Except when the outside temp drops to say -10 and the compensator curve might ask for a 65c flow into the heating system.

But the screed sensor will protect the floor if this happens. Do you get my drift?

You're needlessly complicating things and throwing money away.

Mix the flow to the UFH (with suitable control pack) and run the rads on the standard high temp boiler output...

Or a I missing something too?...

 

[Gray0689]

I want to keep things simple.
Ideally supply the standard radiator temperature (70-50 I think) direct to the underfloor heating. But it will end up cooking the floors and doing damage.

So I'm thinking right size the rads for lower temps so that they will accept ufh flow and vice versa. So the ufh will less likely to be harmed by a high flow temperature.
Except when the outside temp drops to say -10 and the compensator curve might ask for a 65c flow into the heating system.

But the screed sensor will protect the floor if this happens. Do you get my drift?

No I don't it's a silly idea if your not planning to put in a heat pump
As said you will be wasting money
It's very simple to have them as separate units and working at different temps
Think you need a local plumber to explain to you what needs doing
You sound like you have read up
On some theory but not think you grasp the practical side IMHO

 

[Nordio]

I was led to believe modern condensing boilers work best when supplying low temps. But now you mention it, the option of connecting up a heat pump in the future is a possibility.

Modern rads don't get that much bigger with a 0.4 correction factor. A 1000w myson only gets 100mm higher and 100mm wider. Vogel and Noot Rads might be a better option as they have central connections and can be interchanged without modifying pipework. WHat do you think?

 

[Gray0689]

They work best when set up correctly with correct flow and return temps
So your going to possibly fit a heat pump in future what will you connect it into

 

[ecowarm]

Lower return temps for a condencing boiler, so larger rads = lower return temp

I dont think it is throwing money away, exept vogel & noot are v. expensive!

You could have weather comp temp. adjusted rads on one mixer and underfloor on another

 

[ecowarm]

They work best when set up correctly with correct flow and return temps
Sonic your going to possibly fit a heat pump in future what will you connect it into

who's sonic?

 

[Nordio]

An underfloor heating system can tolerate a 50c flow. I think commercial systems can go up to 60c.
So if the radiators are sized for a 50c flow then where is the problem?
At the end of the day I could just turn the boiler stat down to 50c and let it run direct from that surely?

Why the need for separate mixers to the ufh?

 

[ecowarm]

There is no need at all Nordio
just size according to flow temp you require

 

[Gray0689]

who's sonic?

So lol

 

[Gray0689]

There is no need at all Nordio
just size according to flow temp you require

Yes there is a need
What happens if someone turns heat output up?
You will shock the floor possible cracking tiles etc

 

[ecowarm]

Yes there is a need
What happens if someone turns heat output up?
You will shock the floor possible cracking tiles etc

The boiler stat would make no difference, only if someone fiddled with the controller for the mixer valve. That can be protected in the installer menu

 

[Nordio]

Yes there is a need
What happens if someone turns heat output up?

Most ufh systems have an overheat stat on the manifold to cater for mixer valve failures etc. So I can fit one of those.
Or as I've already mentioned the floor screed sensor.

 

[Nordio]

There is no need at all Nordio
just size according to flow temp you require

Thanks.

 

[Gray0689]

There is no need at all Nordio
just size according to flow temp you require

You said there was no need for a mixing valve on underfloor!!!

 

[ecowarm]

You said there was no need for a mixing valve on underfloor!!!

Taken out of context Gray, you sould get a job with news international! LOL

 

[Gray0689]

Taken out of context Gray, you sould get a job with news international! LOL

Lol I'd love to
And was not taken out of context as you wrote it lol