New smart wifi radiator valves from Shelly

Hardware
41

Sorry Bart, I'm not convinced that smart radiator valves are the solution.

It seems to me to be a sticky plaster on a gaping wound, which is expensive, needs regular maintenance, looks ugly, and dependent upon other systems to work.

Has a cost analysis been done - smart valves v traditional TRV's, what are the cost savings, and is this just a technology goal?

I'm not convinced....

1 Like
42

As I've repeatedly said, I find no cost benefit. But there is a comfort and convenience one.

Also, without a matched boiler controller, it would be very hard to get any savings anyway. A matched system like the Wiser or Evohome learns the spead at which rooms heat and so can adjust overrun dynamically. They also take into account external conditions.

43

Hey Paul,
You will not find the word "cost" anywhere in my posts :wink:
It is purely about the familly having to run less through the house to turn on/off radiators, and being able to schedule setpoints so some rooms are warm when we arrive. So 100% comfort reasons, 0% cost reason...

3 Likes
44

There is I believe a 10% improvement due to better control. A trad TRV uses a wax cartridge and a eTRV a stepper motor and a control loop. Where I've gain a saving is on not heating a room until it's needed mainly bedrooms.

For commercial buildings often quoted savings between 10-30% savings.

45

Yes there is a premium for battery free so go with best cost solutions that works for you. I run all my TRVs using LoRaWAN wireless and node-RED.

46

It has a "supper cap" as it's energy store and uses a Micropelt to cover thermal energy to electrical. USB is for backup as long as the valve has been used through the "heating season" it should be fine. BTW they have been deployed for over five years on early projects and some large ones to.

3 Likes
47

Hi. I also have a mix of at least 4 main technologies;- shellies, Tasmota Sonoff,2.4Ghz Mysensors, 430Mhz lightwave RF kit all happily working from a Pi3 running node red.(About 130 devices and counting). I have picked up a lot of hints from the folk on here along the journey and it is very useful to share experience.

For the heating system I too went around the loop on motorised radiator valves but abandoned them because of the mechanical noise they make. This seems to vary a lot and is radiator dependant for the same actuator. I found them totally unworkable for bedrooms and have plumped for a 24v thermal actuator based system throughout. It is much slower to respond than motorised valves (up to 4 minutes or so) and needs wiring (burglar alarm cable) to every radiator. A lot cheaper - between 8-15GBP per valve. The room sensors are battery powered custom arduino mysensors 2.4Ghz devices with small OLED display.

After some fiddly tweaking and using ONLY proportional control it manages to keep most rooms within 0.6 deg C or so of set point - so not at all bad. The only real issue I have run into is high failure rate of the actuators. Out of 16 actuators I have had 4 complete fails and 2 more that are intermittent. The actuators came from a company called Afriso and I think they may have quality control issues.

I will need some more reliable replacement 24v actuators but if I could find some wireless ones that were quiet enough there are a couple of rads in bedrooms pretty much impossible to get wires to. I'd be interested in what folk think of the Shelly actuators.

Also - has anyone else found a source of good but inexpensive 24v Thermal actuators?

48

@coppo23 Hi I've used moehlenhoff oem valves for years for underfloor heating in exact way you using PI control Actuator ALPHA 5 24 V | Climate | Accessories | Theben

49

Thanks. Searched and found them online - Ā£38 each plus vat. That's as expensive as most motorised wireless actuators and about 5 times the price of the (admittedly unreliable) Afrisos. I was going to globally swap out 16 potentially unreliable devices but thats a lot of dosh!

Have you had any failures in them since install?

The afrisos were approx Ā£7.50 + vat. therein lies the quality difference maybe?

50

Yep I might have a few in the loft your welcome to them if I can find them...

51

I'd probably be interested as I'm two down on a complete system (and counting) (as long as they fit a M30 x 1.5 male thread and we can reach a agreeable deal.).
Cheers
Andy

52

Deal is FOC I like to see stuff used I'm a big free-cycler ..

53

BTW I can get the valves at Ā£22.36 from my supplier ex Vat.

54

I'd be more than happy with FOC as long as I can refund your postage.
I replied to your email with contact details but it bounced.
Are you able to send me a PM with contact details?
Andy

55

Andy I'm out tomorrow will take a look on weds to see if I can find any

56

I have some of the cheap zigbee TRVs running (about 6 months) and so far everything seems to be OK
TS0601_thermostat (about Ā£25.00)
They can be heard at night but you have to listen hard. I agree on the cost savings argument (although ordinary manual TRVs can easily cost more) but the big advantage is that you can set different temperatures for different times of day.

Only time will tell on longevity and TTR of the batteries

1 Like
57

Interested how they work. By a PWM signal like servos? How to you generate this signal?

As these seam to be the bare actuators I expect you need a driver to generate the pwm and a mulipexer to distribute to the individual valves and a thermostat (per room) to measure the actual temperature and adjust the valve.

As I canā€™t wire up the all existing radiators and install thermostats on the walls it is a no go for me but when I refurbish some rooms It might be an option.

Iā€˜m interested in the time delay in control when the sensor sits far from the heater. I believe it is ok when the goal is to have a stable temperature but what if you have different usecases over the day i.e. my shower were I love it cosy warm in the morning an average low Temperature during the day and low in the night. And valve closed when the window is open.

58

For the 24v Thermal actuator system I ran wires to all (but 2) radiators back to a central control panel. (The two not wired are a guest room at the farthest corner of the house. Difficult to get wires to but will do it eventually.) Each room has a wireless mysensors arduino stat and node red logic controls the lot, also the boiler and zone valves via 24v relays in a custom y plan wiring box. I used thermal actuators because of the noise and cost of motorised valves - having tried 2 or 3.

The delays in the actuators are an issue - but the biggest cause of overshoot when heating up is the huge old radiators that continue to pump heat out long after the valve has closed. I run a proportional control system at the moment and am just adding derivative to it to try and tame the temperature bounces a bit.. Its still much MUCH better than the old mechanical TRV based system. I am looking forward to seeing how much it has reduced our gas usage.

59

Relays? Does this say the valve is either open or close? Not analog = a percentage open position like the retro fit wireless TRVs?

As noted before I canā€˜t barley hear my ā€žsmartā€œ valves. If the set temperature changes they normaly run not longer then 1-2 second and later perhaps a second once or twice until they found the new sweet spot. Only when I open the window sensed by contacts they run down to closed for 4-5 seconds. And open back to the old valve state when closed again (can even define a boost mode to open to a certain percentage on demand or after a window closed event for a certain amount of time)

What I really like is that all works 100% in the valve. So if I messed up and they are offline or my flows are ā€žconfusedā€œ they still work as expected, perform the on board scheduled and listen to their paired window sensor directly

1 Like
60

Sorry - wasn't being clear. The old Y plan motorised zone valves (water and radiators)and boiler are controlled by node red via relays. The radiator valves have thermal actuators that are PWM'd by node red to give me proportional control. The whole system does need node red running and I know I'm going to regret saying this but I've found NR 100% reliable! The only times it wasn;t was during development when I messed up some 'trivial' change that I hadn;t tested properly. There is a watchdog system running that cuts the power to the heating if node red goes off the rails - better than leaving the boiler turned on. It hasn't been needed - yet!

Re - the motorised valves. The quietest ones I found were from Conrad and were self standing (no wireless). My intention was to convert them to mysensors 2.4Ghz. They were very quiet on the bench but varied from slightly noticeable to very annoying depending on which radiator they were mounted on. They would be fine in a living area but not in a sleeping area. They were the 2nd or 3rd type i tried. After that I made the decision to go with thermal actuators.