Homey Community Forum

Multizone Heating and Smart Thermostats


#1

Currently planning an extension and I’m trying to think about multizone heating…

Can anyone advise on the benefits of multizoning this at the boiler vs multizoning at TRV level?
Seems the standard is to multizone upstairs / downstairs if you do it at the boiler, but presumably TRV offers greater control, but is it actually going to save me money?!

Also, this might be a bit of a basic question/understanding fail, but what sort of cost savings is this likely to make - thinking it through it seems a boiler is going to push a flow of water around the system at a standard rate whatever, so wont closing off a radiator just mean that more water is pushed through the system at a faster rate but still needs heating as much?

Finally, whats the best option to link up to Homey? Is this even necessary?!


#2

About 2 months ago I installed a Honeywell Evo system which can control individual zones/TRV’s. It is not cheap but one of the best systems on the market today. You can programs zones seperately which, in theory, could save on the energy bill. When the kids go to school for example, the radiators are set to 15 degrees Celcius. Also the other rooms are programmed individually. It is way better than all the “intelligent” thermostats because those only measure the temperatue in one room. Evohome is z-wave based and works just fine. It can also be controlled by Homey.

The Evohome also controls the boiler BTW so if there is no demand for heat it will just turn it off or will put it low.


#3

Thanks @Lars_Machiels
I did have a look at that but I think i’m right in saying it’s in essence just 2 boiler zones with TRV?
So, no different to any other system really apart from software etc?
I have read good things about it however.

I currently have Hive, but single zone - was wondering about Multi-zoning it (to two, upstairs and down) and then getting TRVs. Adding in the TRVs might make more sense to go for a Tado instead unless Hive happen to roll some out…

I guess I’m just not seeing how the outlay is worth it tho - i’m well up for smartifying things if it’s going to make like easier or save money, but with TRVs it still seems the boiler has to heat water constantly and push it around the system (slightly less water i guess, but it still needs pushing round) so not sure how much saving that can make

I’ve also read issues with condensation where one room is on and another off etc


#4

I don’t know how boilers at your location work but in Holland natural gas heaters are very common. Most of these heaters are controlled with the “OpenTherm” protocol. This means that the thermostat controls the heater. If there is a demand for heat it will switch it on and if not it will switch it off. Opentherm also has the option to moderate the heat output. If there is not much heat demand the heater will burn at a lower value which is more efficient. So in your case it depends on your boiler system. The question is whether it can be controlled via OpenTherm. If so, the EvoHome might still be a good option (with the appropiate “gateway”) since it will control your boiler too. So with EvoHome both TRV’s (12 max.) and the heater can be controlled. But again, I don’t know how your system works so in your case it might not be applicable.