District heating and cooling

The district heating system is feeding hot and cold water to our house, a 220V valve will switch between the two supply lines. All rooms (6) will have floor heating and a temperature sensor, 220V valves on the circuits. Which Velbus components will be needed to manage the temperature ? How would the heating and cooling be programmed ? Does it need an outside sensor ?

First a few questions:

  • you talk about floor heating and a temperature sensor. Do you mean a Velbus temperature sensor, or a temperature sensor of another system? If another system, what kind of sensor are we talking about exactly?
  • As you undoubtedly know, floor heating is not the same as regular heating, in that it is not meant to respond directly to room temperatures. Usually it has its own regulation which is controlled by outside temperature, heating curves etc. Interaction with it (through Velbus) would concern only “long-term” changes like going on vacation, day/night, week/weekend programs. Velbus can put the floor heating in one mode or another (if the floor heating system allows this, meaning that it has to provide some sort of relay contacts for instance) but direct regulation is normally not the idea. Is this what you have in mind?
  • Which cooling system will you use?

All components will be Velbus (VMBGPOW, VMBGPxW, VMBTC1, VMB4RYLD, …). Floor heating system is Uponor.
The cooling is done by switching the district heating cold water source to the floor circuit.
Yes, floor heating is slow in response and for good insulated homes agressive changes are not needed.

Can you give more specifications on the floor heating system? Especially what kind of inputs/outputs/contacts it provides?

The Uponor Thermal drive TA 230 is used (0.2A, < 3W, 230 V AC) on each return line of the floor heating.
The same valve can be used for the heating/cooling source lines. An alternative would be a 3-way valve, also 230 V AC.

Here are some indications on how you could make your Uponor floor heating work with Velbus. I don’t have full specifications so I cannot give any guarantees, these are only guidelines. You need to check yourself if this will work. The good news is that their room thermostats seem to be simple on-off relay contacts, which (if such is the case) could easily be substituted by Velbus modules.

As I see it, following the diagram on page 6 of the Uponor Control Systems catalogue, you could replace the UP/RF230 thermostats (which seem to be simple on-off relays) by Velbus Relay Modules connected to Velbus Glass Panels. The Velbus Relay Modules would take the function of the relay contact of the UP/RF230 thermostat, while the Velbus Glass Panel would serve as the thermal sensor and regulator, commanding the Velbus Relay contacts according to room temperature, programs etc.
So the Glass Panels would be connected through the Velbus bus with the Relay Modules, which in turn need to be connected to the VE230 module on the Uponor diagram instead of the RF/UP230 thermostats. In this way Velbus could command the TA-230’s.

I couldn’t make out by the specs I saw if the relay contact of the Uponor thermostats are with or without tension. In the first case you would need 2 VMB4RYLD modules (giving you a total of 8 230V relay contacts), in the second case it would be 2 VMB4RYNO modules (giving you 8 tensionless relay contacts in total).
The 6 Velbus Glass Panels can be any of the VMBGPxxx series, these all have temperature sensors and provide from 1 to 32 touch buttons per module. The VMBGPOD modules have a display with a.o. full thermostat functions and programming. For an overview see the Velbus product page and scroll down to the section “VELBUS - TOUCH BUTTONS”.

Switching from heating to cooling mode might be (?) relatively straightforward. The Velbus Glass Panels have a heating and cooling mode. If you can command, by a (Velbus) relay contact, a valve that switches warm water inlet to cold water inlet, you can then put the Glass Panels into cooling mode and things should work. In cooling mode relay contacts close when the room becomes too hot (instead of too cold), so your floor heating would indeed work as floor cooling. So this might work fully automatically also.

Concerning an outside temperature sensor, it all depends if Uponor uses one and if so, how and where it is connected to their system. If you can find information about this, we might be able to help you on this too. However, at this point there is not yet any Velbus analogue input/output module so direct input from a thermal sensor cannot be processed by Velbus (should be available beginning of 2016), nor can thermal curves be programmed. So I think that an outside thermal sensor is beyond the scope of Velbus and would be a part (or not) of your floor heating system independently of Velbus.

Is the VE230 needed ? Are the TA230s not directly connected to the Velbus relays ?

Again, I have no detailed specs on the Uponor VE 230, but from their description as “**wiring unit VE 230 for tidy cabling **of thermostat and thermo drives TA 230 or AR 230 in the manifold cabinet”, I suspect there are no electronic components in there (or at least no crucial ones) and that it serves mainly as a practical and esthetical solution to connect the cables. If that is the case, you could do without and indeed connect the TA 230 directly to the Velbus relays. But as I said before, I can only give indications, please verify yourself according to detailed Uponor specs.

I suggesting you one thing that, I also use is a Thermostat. If you attach a thermostat with your system. Then you can easily operate heating and cooling of your home easily and its not so expensive.