Jump to content
C4 Forums | Control4

How to bring all my Tstat control into Control4


Recommended Posts

I'm planning to try and bring control of all my HVAC into the C4 world..

By doing this I hope to use the EV "Thermostat Controller"driver that integrates multiple HVAC's under the one "HVAC "space"..

If you don't know what I'm on about here, visit their website or use the link below..

OMG. Why are Tstat's soooo complicated!! :lol:

Anyway. Here is the current situation.

Heating: in 2 separate zones via 2 hydronic boilers.

At the moment on/off control of these is via external cbus Relay units. (controlled with CIS Tstat's which are charged and controlled via 24V?? thru the cbus network..I think..... help!!) I think these boilers are 240V, but I'm not 100% sure. The boilers are European (BAXI), so I'm assuming they are 240V.

Cooling:

Upstairs I have a Daikin "Heatpump" with a hardwired Daikin Tstat model BRC1C51/61. I think this is powered off the aircon outside unit, but I have absolutely *N0* idea what voltage.

Downstairs I have Slit system Daikin with IR control

So my questions are.

What Tstat's..and how to wire them?

1/ I'm thinking Heatmiser wifi units with the EV driver to replace the hydronic control. And wiring them to the cbus relays. 2 of these..but can you run two of these independently using the EV driver?.. I ask this because apparently you can only run *one* via the Heatmiser iphone app. And how to power them?..

2/ Would a a Radio Thermostat CT80 with the EV driver run the Daikin hardwired upstairs? But again, this Tstat needs 24V..so how to power it? I also have no idea if this Tstat is compatible with the Daikin.

3/ If I run simple IR control of the split system downstairs, can I pull integration of this into that new EV Thermostat Controller driver: here it is: http://www.extravegetables.com/products/thermostat-controller , so that all this control gets integrated into the one area within Control4..?

Cheers and hope your all lost with the questions :)

Link to comment
Share on other sites


Yes, HVAC is a little annoying especially if it wasn't thought about when the house was constructed.

My Suggestions

Heating

Get the Cbus Driver (bring your lighting into C4 at the same time), create a 2 C4 thermostat in the project (without having a C4 actual thermostat) put a device into each of the 2 zones of heating to measure temp. (the card access devices have temp sensors in them), program the system to get temp info from the card access devices into the fake C4 thermostat, use programming to turn on/off the Cbus relays as needed

Replace the Hardwired Cooling T/S with a C4 one, or the CT80 (although you probably don't need its capabilities) , if that thermostat was also in the area of one of the heating zones above you could use it status to turn on/off the Cbus relays. As for the Power of the T/S most hardwired T/S use a standard wiring and voltage system. You may need to consult manuals or the Hardware manufacture for exact details

As for the IR controlled Split System downstairs, without seeing it this is a tricky one, there are a lot of ways to do it and most have a downside, since all of the smarts are in the split system, so bypassing them can lead to energy consumption issues.

Link to comment
Share on other sites

Some great suggestions. Thanks!

Yes. Unfortunately the house heating and cooling went in before C4 Tstat's were available..and EV were just in their nappies.. :D

Ah.. it's another "If only"..

Home automation is always "if only"..

The trouble with using C4 programming to run the relays is, it will probably be very limited in temp control/hysteresis..way less accurate and responsive than a real thermostat... correct? This is what i do now with cbus: that is doing the heating logic ATM, and I've never been 100% happy doing this..No doubt C4userguy can help here :)

At least with a CT80 it's the Tstat doing the logic. Correct?.. All the driver does is follow the Tstat..

I'm actually tempted to put CT80's in to control the hydronic boilers as well as the Daikin, but I don't know how good they are at this, or whether they can trigger a 240V relay.. I suppose I could bypass the relay all together and wire them straight back to the boilers.. if the Ct80's need 24V, maybe I could then power them via the remaining (then disconnected) cbus cat5 cable??...That is if I can trace it back...

It's a pity nobody has written a way of following cbus temp into one of the C4<>cbus drivers. But I guess there is very little demand for this..

Thanks for the ideas and help. Very Appreciative. :)

Link to comment
Share on other sites

I may be wrong, but im sure the C4 thermostat, and maybe the ct80 (I haven't done much research into it) don't have a learning mode, like a PID controller does.

In a hydronic system, the boilers should have smarts in to react to the need for heat, eg valve opens, gas goes on etc (they have PID control inbuilt). As for a thermostat having PID control I dont know of any, except maybe for NEST

By PID control, I mean the ability for the T/S to work out the size of the space and the amount of energy it takes to get it to heat it, the time it takes to heat, and so the PID control effectively reduces under and overshoot

Not sure if I help or confused here

Link to comment
Share on other sites

^ Not at all.. Not confused at all...

I'll check to see if the CT80 is a "stand alone" Tstat, and how much PID is built in. Thanks for that!

The original Tstats I used for the hydronic boilers were A Landys and Gyr and Honeywell. Both designed for this purpose...

The boilers have very little "self control". Just turn on/off and heat the water.. :)

Link to comment
Share on other sites

Does your system have a master control unit that the T/S talk to. This is important as the heating of the water vs the opening closing of valves should be some sort of PID (or smart system)

As for The Hysteresis, this can be done in programming, its just a setpoint, eg instead of having the heating turn on and off every 3 sec and burning the reducing the life of the relays, valves etc. Its just a setting that says if its set to 23, heat when it hits 22 or 21, and turn off at 23, or 24.

In your case you could actually do real some pretty cool programming based on observation (you could be the PID) you could play around and see, eg. if I turn it off, 15sec, 15min etc after it hits a certain temp below 23 will it reach 23 again and then how low can i let it go before it need to be turned on again to recover back to the required temp in a reasonable timeframe. Obviously its a lot of work and may take weeks to perfect but you could save energy doing it.

Link to comment
Share on other sites

Does your system have a master control unit that the T/S talk to.

No.

And all excellent points. ^

Hey, there is a great idea for a C4app... Run it, the user feeds info into the app ie how they are feeling (whether they are hot or cold) and the app changes the composer logic accordingly.. :)

Link to comment
Share on other sites

Well it goes even further than all I have discussed, and its not so important in Australia as the inside/outside temps are usually within 15degC of each other.

When I was living in Canada, were it needed to be say 22 inside, but could be -22 outside opening a door can create havoc on the system, so having only one form of heat created instability. That's were single, dual and triple stage T/S comes in. In my case I had underfloor heating, then had higher powered heaters to quickly respond to sudden drops in temp. This is were the mix of good T/S, good controlled heating systems with temp sensors in the floor, and high powered (expensive to run) fast response systems all running simultaneous are great. I actually used a mix of the T/S and some programming to deal with the demands.

I know this is a DIY centric forum, and I love the discussions that happen as you can never be too educated. However make sure you find the right integrator, HVAC, etc guy they can really make a big difference in the long run.

Link to comment
Share on other sites

I hope that the Europeans can chime in here, but a T/S just turns on/off the need for heat, it wont control tank temp, valves etc. You need a controller for the tanks, valves etc that the T/S then talks to. If you have tanks, unless they have solar recovery you probably might want to think about moving to a system that is on demand, eg the gas is only on when needed, and how much the gas is on is determined by the output temp of the water. You could do all of this with a C4 system, but as I recommend for alarms and critical systems they should be redundant and not rely on a automation system for control. The control system should just be for guidance

Link to comment
Share on other sites

I hope that the Europeans can chime in here, but a T/S just turns on/off the need for heat, it wont control tank temp, valves etc. You need a controller for the tanks, valves etc that the T/S then talks to. If you have tanks, unless they have solar recovery you probably might want to think about moving to a system that is on demand, eg the gas is only on when needed, and how much the gas is on is determined by the output temp of the water. You could do all of this with a C4 system, but as I recommend for alarms and critical systems they should be redundant and not rely on a automation system for control. The control system should just be for guidance

I don't have "tanks". They are instant on/off boilers... they just heat the water flowing thru them when "on", and the the gas flame shut's off when the tstat shuts them off...

Oh and you'd be surprised how cold it gets here in the South and in the desert centre in Winter.. Sure, not -22.. but close to zero...My Canadian friends say they have never felt colder :)

An excellent discussion... I agree If I could get my baseline hydronic working better together with the separate independent Daikin heat pump (all via the EV driver) it would be way more efficient.. It's the basis of the goal in my OP...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...