Thermostat - Controlling Radiant and FCU

Thermostats: Configuring and Tips
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Good (Canadian) ThanksGiving Weekend to you all! Coming to you from the furthers point East of North America, Newfoundland , Canada.

I have a project where there is a full Distech control system installed and is wired through ethernet cable (Cat5 or 6??)

The installer has ceased operation and password protected the system leaving the customer high and dry. Its been a few year battle but the customer just wants to replace everything so I’m looking for a solution because I cannot run new low voltage wires to each room and fcu etc. Thermos are the big problem.

So looking for advice. Can Tstat’s use existing cat5/6 cables ? Distech seems to run in a loop and then addressable. I guess I could use wireless Tstats (??) Home is also 10,000 square feet and probably 12-14 thermos. It has an extremely complex number of inputs and out puts to try and decribe but it is more the size of the home making it difficult.

The other problem is that the Distech runs multiple sources of heat. So the home has infoor radient heat, complete with manifolds and actuator valves as typical. It also has heating and cooling in the same zones with FCU and air zone dampers. So in winter, heating is via in floor but also though FCU at times because there are Humidifiers that run off the FCU ducting. In summer, the A/C runs through the FCU air handler only, still maintaining humidity as required.

Can the Tstats run multiple sources of heat simulatanouly off the Tstat interface in the room ? If not, I guess the customer could do it via a computer as well. Since the house is large, it might be better than having to go to each room to change temps etc..

Just wanted to start the conversation and see where it could go.

Thanks in advance guys !

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For sure you can power the thermsotats over a cat5 loop. Keep the total power consumption in mind, each stat ues up to 1VA and from a quick google search each pair of Cat5 can handle about 12VA. If the runs are long you will want to watch the voltage drops. There’s 4 pairs in the Cat5 so you can double up the power carrying capability with another twisted pair.

As far as RS485 communications is concerned, use one of the twisted pairs to run a daisy chain from each thermsotat to the next.

For the sequence of operations, its a complex system but the Tstat10E can be programmed with whatever sequence you can dream up. There’s a humidity sensor as an option on board the Tstat10E to help with the humidifier control.

It would be worth checking out what Bacnet objects on the Distech system are exposed. You might be able to make a lot of the devices usable as generic input and outputs to the system and do the control in a new T3-nano for example. Use the ‘Yabe’ bacnet tool and see what you can see there, just download the free T3000 application and navigate to tools, bacnet tool. There’s many references on the forum on how to operate Yabe.