Weather Compensation on Both Rads and UFH?

[ALEC1]

vaillant's is just the same if you don't want to spend a lot on headers and pumps..... and its because of the way they use heating systems in Germany..(they have to have out door sensors, but no indoor sensing which is optional but not necessary!)


where as we wait till we feel cold, german technology works to avoid you feeling cold. thats why they don't let things get too cold, and avoid scenarios where buy you have to use an unnecessary amount of energy to raise the temperature quickly.

 

[Andygasman2010]

Here's another option...

Worcester 30CDi system with integral diverter valve, facia mounted FW 100, as many zones as you want (either UFH or rads) each zone having it's own programable stat wired back to LR via the zone valves.

The FW100 is a hot water timer, and a heating timer with an outdoor sensor which must be left on constant.

You'd have to set the curve to the rads and let the manifolds/mixers/pumps deal with the UFH.

 

[GeorgeWBush]

Hi Andy, thanks for this and your previous posts (which I forgot to thank you for!).

You'd have to set the curve to the rads and let the manifolds/mixers/pumps deal with the UFH.

Would the UFH temperature be influenced by the outdoor sensor?

 

[Andygasman2010]

Only when It asks for less than approx. 50c because the pump mixers will limit it to that anyway. I'm not as clued up about this stuff as some of the other guys on here but I often find that advice gets over complicated because of a little one-upmanship

It's arguably not worth having WC on UFH seeing as flow temperatures are so low anyway, especially on a domestic level in an average house. added to the fact that you have rads too maybe this is being over engineered.

The Worcester option I described earlier is really simple and if you decide you don't like the WC it can be removed at any point, no plumbing required. You could even do it youself amd fit the DT20 which is a standard on/off timer.

 

[ALEC1]

one upmanhip I am not so sure about...i guess its about what the client wants I guess...

To my mind its pointless to spend money on an install and not get the most developed and considered...one that will survive the test of time, and be the most efficient to run...


by applying uk understanding to german heating technology you regularly end up with a lemon....

it is no more expensive to install weather compensation, which is ideal for UFH due to the themal lag of the floor and building...

 

[Andygasman2010]

The FW100 is the first in the chain. It monitors outside temperatures constantly telling the boiler what flow temperature to produce. It won't actually fire up unless it sees 240vac on the LR terminal which can potentially be from any number of programable stats that control rads or UFH.

The boiler won't descriminate between rads an UFH. It will produce a flow temperature based on the outside sensor then your programable stats/zone valves will tell it where to go.

 

[ALEC1]

this is a bit of a gamble, as the injector valve probably need a flow temp of 70c min to work effectively...it depends

 

[ALEC1]

wb have a mixing valve for UFH too , I almost guarantee it...

 

[Norcon]

it is no more expensive to install weather compensation, which is ideal for UFH due to the themal lag of the floor and building...

How much exactly will it cost and do you think its worth it for one room of ufh?

 

[Andygasman2010]

one upmanhip I am not so sure about...i guess its about what the client wants I guess...

To my mind its pointless to spend money on an install and not get the most developed and considered...one that will survive the test of time, and be the most efficient to run...


by applying uk understanding to german heating technology you regularly end up with a lemon....

it is no more expensive to install weather compensation, which is ideal for UFH due to the themal lag of the floor and building...

I'm totally on board with load/weather compensation. I'm not sure of any of the facts as I've not had much chance to put it into practice but the technology makes perfect sence to me. I'm currently quoting for a similar job to this and it's been very interesting doing the research.

Alec, do you have any experience with Worcester compensation controls?

 

[ALEC1]

about £400 plus the vitodens 200. you dont need controls from the ufh manufactuere so you save probably more, plus the time spent wiring those controls.

yes it is wirth it on every count.


my experience shows that injector vales cause a lot of unnecesary issues for a lot of systems...

 

[ALEC1]

no no experience of worcester bosch, many of their boilers cannot take compensation controls so are only for the UK market

 

[Andygasman2010]

wb have a mixing valve for UFH too , I almost guarantee it...

Good point! OP, have you decided on what UFH equipmnt you're using yet?

I assume it'll be mixer/pump sets as it's only a small UFH system.

I'm starting to think WC with rad and UFH with one boiler just isn't practical...

 

[ALEC1]

yes it is i do it all the time...


ufh with weather comp brings down the return temperature which increases system efficiency... but not with the kit from a ufh manufacturer...

 

[Andygasman2010]

It's only two rooms of UFH though, seems a bit overboard to have electronic mixers seeing as it'll get pretty expensive.

So if you have a mix of rads and UFH what's the ideal set up?

Worcester's new CDi range all take compensation controls now.