Domestic zone control

[p7777m]

I am installing 2 radiators in a room and am looking at creating a zone to control these - using a 2 port motorised valve, adjustable restrictor valve to balance this circuit against the rest of the heating installation, and a room thermostat.
The motivation is to be able to mount the radiators closer to the wall than can be achieved using TRVs, for aesthetic puroposes. These are rear tapped Ultraheat Aeon designer radioators - thus to use a TRV I need to fit a 90degree bsp elbow then mount angled TRVs under this with pipe exitting into the wall (or straight to floor but this doesn't affect spacing). Using the Ultraheat-recommended elbow & TRVs I end up with the gap betwen radiator fins and wall being around 80mm which to me looks very ungainly given that the fins are just 10mm deep. The recommended elbows and TRVs are very compact. I don't believe there is much scope for gap reduction by using components sourced elsewhere.
Will my zone work?
Is there a better solution?
Will a room thermostat give as good control as TRVs? I've read about the hysteresis built into roomstats resulting in slightly fluctuating room temperatures. I presume this doesn't happen so much with TRVs because they adjust flow according to demand locally rather than having the need for hysteresis to avoid frequent short (inefficient) bursts of boiler activity.
Have I missed something?

 

[Hufty]

In line (rather than angled) valve if pipes go down into floor?

In line thermostatic valve under the floor with remote sensor up the wall?

Something based round a Danfoss FHV?

Would it make sense to have the thermostat for the whole house in that room? Then you wouldn't need TRVs on the rads and you wouldn't need a separate zone.

 

[p7777m]

I really wanted to avoid pipes going down to the floor - to achieve a neater installation.
I didn't realise remote sensor valves were available. Are there alternatives to the Danfoss FHV? Are these all intended for use with under floor heating?
Re: roomstat in that room: actually I'm planning to do this in several places in the house... they can't all have the master control.
Also, doesn't the room/area with the overall thermostat really have to be the most under-endowed with radiators in the whole building, or at least have the lockshield adjusted so the radiator seldom fulfills requirements - otherwise the boiler may well be off even though TRVs everywhere else are calling for more heat.

 

[Hufty]

They were all just suggestions. FHV may or may not work with radiators - you'd have to read the specs - but I can't see why not as all it does is choke the water flow as the air temperature rises.

If you're contemplating a room stat in every room I would question your design. Or don't have TRVs - you don't go to prison for not having them, you just pay higher bills and your grandchildren won't be able to holiday in Tahiti etc etc.

As to your last point, yes that can be correct, but surely you've sized the radiators correctly for the rooms? Also depends whether the stat is a simple on/off one, or if it is a more "intelligent" control offering some sort of load compensation ie the boiler throttles back as it approaches the target temperature.