Intelligent programmer and weather compensators.

[fizzput]

I'm looking into a system which firstly gauges time required to reach heat and adjusts intial firing times for the boiler to acheive required room temp, and secondly does this while accounting for external temperatures.

The aim is to maximise the efficiency of the boiler run times.

I have researched a Dataterm programmer by Warmworld which i have seen to get good comments from various sources. This company also does an optional external sensor which i guess would be fine, however i see Valiant do a weather compensating sensor and Drayton have recently bought out an RF3i (intelligent programmer...) which may hook up with the Valiant sensor....

Does anyone have any experience of any of these components?? Not huge demand for these i think as none of my usual merchents have anything solid to say...

Cheers Mark[/quote]

 

[simond]

I haven't fitted the Dataterm but it looks like a sixth form project. Their web site sounds like they are hawking a product which was reasonably clever ten years ago but has now been left behind. One look at the thing must tell you that, before you read the guff.

The Drayton unit is a basic optimising controller and as such cannot achieve the savings of the manufacturer weather comp controls from the likes of Vaillant, Viessmann, Broag-Remeha etc.

The Vaillant system solution is not compatible with the Drayton, although you could fit a Drayton RF3i to a Vaillant boiler (or any other boiler) without weather comp.

You may be able to fit a Dataterm to a Broag but use the Broag weather sensor, you would have to ask Broag to be sure.

If you want to save energy on an existing system, look at Honeywell Hometronic. It is a few generations ahead of what Dataterm are offering.

 

[D_Hailsham]

I haven't fitted the Dataterm but it looks like a sixth form project.

And they are asking £250 for what looks like something cobbled together from bits bought at Maplin

The Drayton unit is a basic optimising controller and as such cannot achieve the savings of the manufacturer weather comp controls from the likes of Vaillant, Viessmann, Broag-Remeha etc.

Vaillant have their own e-bus, while Viessmann and Broag adhere to the Opentherm Protocol, which means any Opentherm thermostat/programmer can be used.

Might be a good idea if the OP told us which boiler he had.

 

[Deleted member 105431]

I agree the datatherm is garbage. If you have a Vaillant use their controls otherwise go with Honeywell would be my advise. You need a condensing boiler to get the most out of weather comp though.

 

[fizzput]

Thanks for all the above responses...

Boiler is a W-Bosch 42 cdi...actually after chatting to a few people about who were able to offer good info on these controls they don't really seem to offer much more benefit then say..extra insulation.....especially with the W-B range (and others i'm sure) modulating gas flow to keep boiler at optimum condensing temp etc

thanks again

 

[Onetap]

I'm looking into a system which firstly gauges time required to reach heat and adjusts intial firing times for the boiler to acheive required room temp, and secondly does this while accounting for external temperatures.

It's called optimum start/stop and weather compensation respectively. In use on thousands of BMS outstations. See a Trend configuration manual (for one example).

 

[D_Hailsham]

It's called optimum start/stop and weather compensation respectively. In use on thousands of BMS outstations. See a Trend configuration manual (for one example).

There was a Trend system managing everything at the college I worked for. The whole lot was controlled from a computer. Trend don't make anything for the domestic market, so it's not much point pointing the OP in that direction.

Honeywell, Drayton and others make Optimum Start programmers. These adjust the time the heating turns on in the morning, according to the internal temperature, so the house is up to the set temperature when you get up.

Weather compensation adjusts the water flow temperature according to the external temperature.

Edit:

The WB 42CDi does not have any weather compensation facility.

An optimizing programmer is worthwhile.

 

[fizzput]

appreciate 42cdi has no weather optimiser

Have had my mind kind of set that perhaps in domestic uses at least this is not so usefull, if boiler is told by room stat to fire until say 18 celcius is acheived, does the boiler really have to care if it's 18 or -18 outside, it still has to fire to warm the house up (or maybe not if it's 18 outside...anyway...)

I guess it comes down to the fact that a weather compensator may decide at -18 it needs boiler to fire for longer therefore will start heatup earlier to attain required temp and corrospondingly later if warmer...

guess also weather compensator needs an optimum start programmer to tie this external sensor info into firing requirements....

Does any one know any statistics (or have any experience/opinions!) to show what kind of efficiencies are gained using these controls over a standard system??

 

[fizzput]

The WB 42CDi does not have any weather compensation facility.

Ah, so not possible to use w/c with 42cdi at all??

 

[simond]

There are ways of bolting in post mixing weather comp but it is not as integrated or fully featured as a boiler internally managed system -for domestic use anyway.

If you want WC you should have bought a different boiler, like Vaillant, Viessmann etc.

 

[fizzput]

No, i have not yet bought a boiler, i'm quoting for a customer and usually do WB...

I'll look into the Valliants....cheers simon

 

[D_Hailsham]

i'm quoting for a customer

Ah! At last the OP admits that he is a "professional" picking the brains of other "professionals" and amateurs.

The Viessmann, Broag-Remeha and some others, e.g Keston, have Opentherm connections, so they can be used with any Opentherm Programmer/Thermostat, which has built in optimization and weather compensation. The only problem is that Opentherm has not really taken off in the UK, so it is not easy to get hold of the programmers and thermostats. Danfoss sell a thermostat but not a programmer. Siemens do one and so do Broag Remeha. Honeywell make one, but it is not sold in the UK. The other possible drawback is that, at present, there is no wireless version of Opentherm. This is because there is two-way communication between the boiler and the programmer/thermostat.

An optimizer decides when the boiler should come on to reach the required temperature at the required time, e.g 20°C at 0730, when I get up. How long the boiler needs to be on will depend on how much the temperature has dropped overnight, which depends on external temperature and insulation.

The weather compensator adjust the flow temperature according to the external temperature (colder=higher, warmer=lower). This is because the heat required from the boiler will depend on the difference between external and internal temperatures. The heat output of a radiator is not fixed as it is in an electric fire.

 

[fizzput]

Ah! At last the OP admits that he is a "professional" picking the brains of other "professionals" and amateurs.

Uh oh....don't start me on things i should to admit....it'll be a long and painful experience for all concerned

Thanks for you informative previous post D...I am new to this area of heating science(?) but as more people/customers get concerned about the environment or, more likely...rising gas prices, efficiency of heating systems is of increasing interest to me...possibly to create a niche market...maybe be slighty ahead of the game, but also just cos it's part of what i do, don't know much about it so plugging the knowledge gap..

If you, or anyone else could bear with me for just a couple of q's that come to mind after you previous post.....

From what your saying about the optimizer system, this does everything that inquired about at the start of this thread, weather compensator is itself a slightly different kettle of fish and not needed to get the external temp accounted for in firing times...

Also, where's the written science on all this, a good site or book to head to? Is this like heat source which everyone in europe is mad for, but leads to many blank looks this side of the pond??

Thanks

Mark

 

[Norcon]

fizzputt wrote

Also, where's the written science on all this,

"Building Control Systems" from cibse (Guide H) is quite good. If you want a more in depth study then try "HVAC Control Systems" (by C.P. Underwood)

 

[fizzput]

Thanks Norcon, i'll look those up.