Temp sensor problem

I have a customer who has a ducted split system, they want to set a maximum or minimum temp on the main thermostat then zone off every room with a damper and a T/S in each room and have control via the Ctouch to turn the zone on or off switch between heating and cooling and adjust the temp in each zone within the maximum set from the main thermostat.
any ideas?

 

Yes that's sums it up

 

A guy out at Leeton setup a similar system, house owner was in the climate control business.. 13 touchscreens, etc..

I have the electrical contractors/programmers details if you want to give him a buzz to chat..

 

That would be great, thanks, how do you want to get his details to me.

 

There are many ways you could skin this cat!

One way would be to put a CBus thermostat into each room and use the relay control off the back to control the damper for the room.

You could also use older in wall CBus temp sensors or the new 5104DTSI module and some 1-wire temperature sensors and central CTouch screen for control with a LV relay board to control the dampers ... but again an on/off control over dampers only.

What else can you tell us about their requirements?

When you say a T/S in each room, are you talking about a CTouch? DLT? etc?

What are the controls over the dampers? are they controlled by the ducted system? is there any smarts to the ducted system at or, or is it on/off ?

There are also a number of third party wireless temp sensors you could use for a similar result - just needs a fairly basic interface to bring the information into the measurement app so it can be used like the clipsal devices ...

You can show the temperature on a DLT with a bit of coding on a touch screen or CGate app and you can use a DLT to set the temperature in a similar way.

Depends on what type of solution and outcome you want

 

At the moment the ducted split has a main thermostat which they set the max or min temperature there was another 3rd party unit that linked the split to the dampers and allowed them to set an individual temp in each zone via a local sensor (t/s) that would open or close the damper.
this third party unit is dead and the customer has been advised by the A/C company that it is not worth replacing or fixing, so they asked me if I could blend it with the Cbus & Ctouch.
From what I understand the 3rd party unit allowed them to turn the zone on or off and set a temperature either lower or higher than the max or min temp at the main thermostat.

 

Not sure on what budget you have ..


But I would go for the new 5104DTSI modules with 1-wire temp sensors in each room - they are a fairly small transistor that can be mounted anywhere you like, they should be mounted around the same height as the light switch and have air flow across them so they have a chance to provide a representative reading for the room.

Then I would find out how the dampers work.

They may just be a solenoid that requires a fixed voltage to open or close - this could simply we wired through an ELV relay box to open/close the damper.

Or they may be stepper or ordinary motor operated. These could take a bit of sorting out to get right - I have seen some people try to time how long it takes to go from open to close, but I prefer to use limit switches - both options can fail ... see what you have to work with.

See if you can find a zone that is permanently open, or you will need to nominate one in case all the others are closed, if the dampers allow, partially closed.

I would then build the CTouch code - not sure I would bother with in room controls - for the amount of time they are checked or used I would suggest they are OTT, but up to the client!

Then, depending on how much coding you want to do, you can go crazy with the control side, or just leave it relatively simple ...

To give you some ideas .. this link will show you a page from one of my projects that includes a fair bit of code to also manage individual room set points ... http://www.foresterit.com.au/Colour Touch/Bedroom with HVAC.jpg

As I said before, once you have this code going, it is not a lot more work to show the temperature on a DLT in the room if they want to add those in - but probably a lot of expense for what is probably only a 2 button light switch (room + corridor) ... and then also put a slider on there that can be used to adjust the setpoint ... you may also be able to make it look/work a lot better with the new eDLT's, but I havent had a chance to really play with one yet!

 

Thanks for your help I will price it up and see what they say.