Introduction to automation

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akist

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Seeking some advice and opinions. We are just about to 1st fix plumbing and electrics.

I am very very new to all this and after reading here and there I think I can have a smart boiler timer/thermostat which would connect wirelessly to a number of thermostats around the house, and those thermostats (or the main hub) could then instruct individual, wireless radiator valves on and off.

That means my CH piping installation would be almost "standard". Because the house is large I may have a couple of extra valves to divert CH water to the right area of the house.

I would have standard radiators fitted with a wireless valve which would be controlled by the main hub.

That means my CH could potentially heat a single room only.

Am I understanding it right?
 
Yes, smart radiator valves are akin to someone manually adjusting the dial on a conventional radiator valve. The benefits are that you can set temperatures per zone, and the system will call for heat when required.

There are quite a few systems on the market that do this. Heat Genius and Tado are two major ones. Neither are especially cheap, however.
 
I presume the thermostatic radiator valve does not need to be "thermostatic" and not need to display temperature, but simply be a gate valve, as it is being controlled from the main hub. But all I have seen so far is thermostatic radiator valves.
 
Most valves measure the temperature so you can achieve a target temperature in each zone. At their simplest, you could use them as bog standard thermostatic radiator valves, except you use an app to configure the set point rather than twisting the dial to arbitrary numbers. (They often also have physical controls on the valve in case of system failure)

It should be noted that these thermostats are hardly representative of the temperature of the room as a whole - obviously the valve thinks its warmer than the room is when the radiators are on, and (assuming your radiators are under the windows) colder when they're off.

Some ecosystems have additional room thermostats you can use to substitute for the value sent back from the radiator valve.

Frankly such extra thermostats are often unnecessary unless you have a specific need to heat a room to an exact temperature. In my parent's home, we just learnt through trial and error what reading from the valve felt comfortable.
 
OK I will then assume that a wireless TRV will be naturally controllable from the main hub, regardless its own temperature settings/dial.
jado84 said:
Some ecosystems have additional room thermostats you can use to substitute for the value sent back from the radiator valve.
Click to expand...
That is exactly my thinking: a thermostat in most rooms, maybe next to the light switch, so you can set the desired temp. And always overridable by the central hub.

jado84 said:
Frankly such extra thermostats are often unnecessary
Click to expand...
I am thinking a very large house with occasional use of rooms. Eg son visiting for weekend. He walks into room, sets the temp to what he wants, when he leaves he switches it off, it will be next to the light switch. Of course he should also close the room door. And if he forgets, we can use the app to switch things off in that room remotely (from other rooms, or even from outside the house).

At its most basic one should be able to switch heating on and off in a room just as they do for the lights, even without temp adjustment.
 
akist said:
Of course he should also close the room door. And if he forgets, we can use the app
Click to expand...
to close the door.....

Obviously that is taking it into the realms of stupidity , or is it, the complexity of "Home Automation" seems to have no limits
 
If you want to go all-out, Genius Hub even have motion sensors to deactivate heating when zones are vacant. I don't know how it copes with, for example, someone sleeping as we've never used the motion sensors for anything but lights.

I don't know of any brands who offer "smart radiator valves" that offer ones without any in-valve temperature sensing, but you should just be able to override the values with the thermostats.

Worth thinking now if you're having your first fix done about if you want to be getting low voltage wiring run to the places you want the thermostats. I'm sure some must support wired power, and I imagine changing 10+ batteries every six months will get old quickly.

Possibly also worth installing at least the "hub" of the heating system before the boiler goes in, and asking the gas engineer to wire the hub up for OpenTherm rather than just switched contacts (if the boiler supports it). Sounds like your system is going to be fairly complex and there could be some reasonable cost savings if your boiler is being controlled more intelligently than just on and off.

If you think you'll possibly want smart light switches in the future, make sure the electrician runs neutrals to the light switches to avoid any of the gross hacks the manufacturers have come up with for no-neutral light switches.

As my final bit of unsolicited advice, consider having ethernet run from places you can foresee a desk/TV being put back to an out-of-the-way central location. If your house is very big, hallways etc may be helpful as you can install access points to improve WiFi coverage (WiFi mesh systems tend to be trash). If you want external security cameras etc now is also a good time to think about running ethernet for those.
 
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Much depends on the boiler, but basic idea is the TRV controls the water flow so the room is the temperature required. And as the system uses less and less water the by-pass valve opens sending hot water back to the boiler which then reduces output.

But the boiler has a range, say 8 kW to 28 kW once using less than 8 kW the only option is to switch off/on.

The boiler could be made to switch off, but until water flows it can't sense if it needs to switch on, so we have the wall thermostat, which will only switch off when the TRV has nearly fully closed so only activates on a warm day.

The problem is every thing needs to be carefully balanced, and the room with wall thermostat needs to be the fastest cooling room. So all the rest is to make the installation easier.

OK there are a few things, like programmable TRV heads, which can be added, and having the TRV tell a hub/thermostat when to switch on will clearly help. But that's the icing on the cake.

There is another method, that turns every thing upside down, instead of controlling water flow we let water flow unrestricted, and the radiator output is controlled by the fan speed, all radiators can be in series not parallel and the coolant (water) can both heat or cool as required, but if you look at the price of a Myson Ivector fan assisted radiator you will see why not used with domestic installations. Also the building management package it not cheap.

We can use OpenTherm etc. But the big question is if set up correctly to start with, how much does OpenTherm help?
 
ericmark said:
and the room with wall thermostat needs to be the fastest cooling room.
Click to expand...
Why can't most/all rooms have a thermostat, each independently asking for more or less heat? So the boiler starts when at least one thermostat somewhere in the house asks for heat. From there, as each room has its own radiator valve, HW will only flow where it is needed. I am thinking if the house is too large, the HW circuit can be split into 2 or 3 sections.
 
jado84 said:
Yes, smart radiator valves are akin to someone manually adjusting the dial on a conventional radiator valve. The benefits are that you can set temperatures per zone, and the system will call for heat when required.

There are quite a few systems on the market that do this. Heat Genius and Tado are two major ones. Neither are especially cheap, however.
Click to expand...
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Start by researching a boiler that allows for flow temperature control AND room temperature control. Then consider the use of a dedicated hot water on demand and the temperature you want system to compliment to heating system. To compensate for a DWH recurculation, switch hot water outlets (not bath or shower of course) to 10mm plastic. Then enjoy large properties that have a constant temp and humidity while having a delta t of 10....heating a room from cold is false economy in terms of building fabric, radiated comfort, condensation and draughts.
 
Takes me time to understand all that. Better speak to the plumber to see if he understands what we need to do.
 
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