Added value of thermostat if using ST to set rules and schedules?


(hakem) #1

Dear all,
I have a basic ON/OFF water heater which works in constant mode presently (no intelligence, nothing). I wanted to add some smart behaviour to optimize energy. I do have a SmartThings Hub2 and willing to purchase some “temperature sensors” to be able to better control the heat in various spots of the apartment.

After reading many posts, I realise that existing solutions are expensive because intelligence is in the Thermostat itself.

Considering, in our case, intelligence is in the Hub System, I conclude that ultimately there no need to invest in a smart Thermostat, this latter would only have to abide the commands from the SmartThings Hub ( 2gig CT100 was recomamnded at 70 USD).

In this case, I wonder what is added value of purchasing a thermostat. Would a z-wave enabled Relay not work to control the heather right from the ST smartApp, which collects temperature from temperature sensors and then order to turn heather on or not ?

I’m I missing an important component in the Thermstat setup ? ( beginner )


(hakem) #2

I did some reading and will put a note in case of interest.

My understanding of thermostatic necessity is summarised as : It depends how far we want to go with energy optimiation or control :

1-) If the ris : equirement is: I just occasionally wnt to turn off/on my heater wmhile I am on holidays or on set times while I am not at home . And have a fixed temperature then, indeed. A simple outlet plug / relay which turns on-off controlled with z-Wave would definitely do. Total cost of operation ==> + - 30 USD on top of the Samsung Hub;

Pro: Low cost heater control integrated with Smart Home automation;
Con: Its on / off. If heater is same used for hot water, all would be turned off.

Still, this setup may work well for vacation house airco or so.

2-) If requirement is: I would like to control temperature with more specifid needs such as : based on presence in the house and keep stable temperature, then a smart thermostat such as NEST / Ecobee would be good. Because they not only have temperature sensor, but also presence sensor and connected through Cloud to outside temperature , street temperature according to google Info and compile all this data, to ultimately control your heater system.

This justifies + - the high price beyond 160 EUR.

3-) If requirement is: You have a multizone environment with different temperature to be controlled, then probably, TRV thermostatic valves to be pluggued in radioators is an interesting alternative.

4-) If requiremen tis: I would like to manage temperature accurately by controlling internal temperature of the heater, check its feedback water temperature. Then a protocol based thermostatic system, which uses protocoles like eBUS / OpenTherm ( in Europe) and maybe others, is the way to go for more detailed level.

So, as usual, like people say: “money does not lie”. Price is somehow justified by features demanded.