Vaillant weather comp - lower heating curve = less gas used?

[Agile]

I believe it is more about there being available clear detailed information about enablers to change. Often technical information is no better than the advert that says its good for me which does not help; one needs to know practical detail about what it does for me yet so often these things are so very hard to find out about

For example WB do a controller with WC, its the FW100 - try finding out about what it can do for you things like :- zone control, (how many); on/off times per day (how many); temp settings (how many); is it configurable ......

You will have a friend in Alec about the lack of technical information. But as he says, you need to start with an understanding of controls and what they can and cannot do.

The Worcester FW100 is I find very good indeed. The instructions are not great but actually programming it is very intuitive and I found that easier.

Its only a weather controller and uses a single interior sensor. It is not intended and cannot specifically control seperate zones. Thats harder than you might imagine.

However, I went to a focus group recently about a new plumbing product. I was the only one out of eight who wanted a technical description of how it worked. All the others just wanted a simple non technical sales style document.

Tony

 

[ChrisR]

You will also need someone (else) who has some basic understanding without delusions.


Someone who publishes rubbish about thermostats, confuses boiler efficiency with seasonal system efficiency, thinks that he has the only figures on working systems, and doesn't explain anything about future issues, may not be such a good friend.
(Oh - and summarises control options incorrectly, goes off at a tangent, can't read, can't follow a line of discussion, can't see his own delusions and shortcomings and lack of knowledge ..... yada yada yada...)

Be careful what imaginings you're being asked to believe in.

 

[Onetap]

My understanding is that heat curves are particular to the property construction ( and a smaller extent its exposure to winds etc. ).

They are, the overall U value, ISTR.
Details here, in imperial units;

http://www.pmengineer.com/Articles/Feature_Article/cdd55d5472298010VgnVCM100000f932a8c0____

But then, it's WC, if one curve proves too cold, you can turn it up.
WC originated with commercial zoned heating systems, in the days before TRVs; central control of the zone flow temperaure was the only means of controlling room temperatures. Basic WC ONLY refers to the outside air temperature and the zone flow temperature, not the internal temperature. This doesn't work well, IMHO.

Most of the benefits of WC are in comfort, having the radiators running continuously at a moderate temperature and with a consistent room temperature.

The previous system I had was self-programmed WC system operating a mixing valve.
I changed that to the Vaillant ecoTC 618, VR65 S-plan & VRC 430. I'm not greatly impressed.
I going to change this back to a controller I can set up myself.

 

[ALEC1]

The vaillant controllers have all the parameters you need, some in the boiler and some on the controller, it's just a question of understanding the poorly written instructions....

 

[gaswizzard]

You will also need someone (else) who has some basic understanding without delusions.


Someone who publishes rubbish about thermostats, confuses boiler efficiency with seasonal system efficiency, thinks that he has the only figures on working systems, and doesn't explain anything about future issues, may not be such a good friend.
(Oh - and summarises control options incorrectly, goes off at a tangent, can't read, can't follow a line of discussion, can't see his own delusions and shortcomings and lack of knowledge ..... yada yada yada...)

Be careful what imaginings you're being asked to believe in.

Although never seen eye to eye I've gotta agree.

 

[ALEC1]

Most of the benefits of WC are in comfort, having the radiators running continuously at a moderate temperature

you don't need weather compensation to achieve this... any compensation controller will do it..

depending on system design flows hover around an average much lower than a random fixed set point with on off controls...

some of the energy saving is the condensate effect, but I think most of us are agreed its unlikely to me much more than 3-4%

the neccesary system design enhancements add to that, hot water priority (which comes free with combi's) for example, and may be the electronic mixing valves for UFH..

Vaillant and Viessmann systems work well with NO indoor sensing...the other don't..

To Gas wizard, whey would a technology that forces the flow temperature as low as possible to match demand with out compromising comfort, not save energy....the boilers turn off just like on-off controls but modulate around the target flow temperature...

 

[Onetap]

Most of the benefits of WC are in comfort, having the radiators running continuously at a moderate temperature

you don't need weather compensation to achieve this... any compensation controller will do it.

The underlying principle of WC is that it sets the flow temperature according to outside temperature so that the heat emitted with continuous operation of the heating system is approximately equal to the heat losses.

The heat emitted in each room should match the room heat losses and control is not based on an indoor air temperature sensor in a 'representative' room, that usually proves to be unrepresentative.

A system which controls solely according to an indoor air temperature is not as effective, under stable steady-state conditions IMHO.

WC takes no account of internal heat gains, solar gains, warm-up times, etc., and is not effective unless it incorporates a control over-ride that refers to an indoor air temperature.