Messages

1

Developers / Re: Danfoss RA-plus - controllable with linuxMCE 0710 ?

« on: February 18, 2009, 06:12:40 pm »

The control it gives is all that's needed as setting a room temperature back more than 4C will take too long to get back to the "normal" temperature.

really, that depends on your needs. You cannot make those assumptions for all scenarios. That is the reason why there are other types than setback schedule on the market :-)

A 4C setback was chosen because it's sensible for almost all scenarios. We need to compare eggs with eggs, you seem to me to be comparing it to a conventional thermostat ,a Z-Wave one or otherwise that controls the heat source for the home. The wRA+ is NOT a temperature controller of the home, it controls a room or more correctly a radiator. In all applications the wRA+ would also be used with a thermostat Z-Wave or conventional, after all it can't switch the boiler on or off, that's not its job. 

Now if we compare eggs for eggs, for Z-Wave you can either fit a wRA+ to control rooms or as you suggest a Z-Wave non-setback thermostat and a control valve in each room.
However even now do you have control you think you have? 
What happens when the house thermostat wants 20C and your bedroom thermostat wants 24C?
The house stat detects 20C and switches off the boiler, but your bedroom stat is at 21C and wants heat, what happens then?
The only way to get this total room control that you want is to have each room thermostat control not only its own room valve, but also control the boiler as well.
For me I'd rather plonk a few wRA+ units around the house and use a setback schedule for each room.

The other advantage is that if your z-wave network goes down these will still control your room temperature.

hu? The other Z-Wave thermostats usuall have local control..

see above

Phil

2

Developers / Re: Danfoss RA-plus - controllable with linuxMCE 0710 ?

« on: February 17, 2009, 09:26:12 pm »

Hallo Hari,

be aware that it only supports setback for some degrees and no full controll (it is a setback schedule thermostat :-) )

Thanks for telling me I already read that before and am not 100% happy with that, but maybe there is a good reason for doing it that way. Is it maybe more economic on a daily basis ? But it would be nice if one could turn heat more down when one is on holidy

I think you all misunderstand a bit, the Danfoss wRA+ does have only two settings such as: (day & night) or (normal & setback) or (your temp & your temp-4C), the unit includes a built-in TRV (Thermostatic Radiator Valve) that you can set just like any other temperature controlled radiator valve. You can still set your living room to 20C and your bedroom to 19C and your office to 21C, all that happens is when this rooms are "setback" they will go to 16C, 15C & 17C. As for the turn the heat down when on holiday this would be via your main thermostat and not via the individual room control. The control it gives is all that's needed as setting a room temperature back more than 4C will take too long to get back to the "normal" temperature. The other advantage is that if your z-wave network goes down these will still control your room temperature.

Phil
 

3

Users / Re: PLCBUS scenes (vs Zwave?)

« on: May 16, 2008, 06:38:51 pm »

Hi.

Does anyone know if there exist zwave wall switches that are powered with 220v instead of a battery?
I´m looking into zwave instead of plcbus above damand but lack a thermostat like the Danfoss Radiator Thermostat  (RA PLUS).

/niz23

There are two versions of RA Plus, the Z-Wave version is the RA Plus-w, see the Danfoss website on the product at www.raplusw.com, the standard RA plus is a programmable thermostat.