Understanding floor heating settings/controls (stadsverwarming)

[PierpaoloB]

Hi, sorry for speaking in English (I hope it's allowed), but I couldn't find any other helpful website.

I have a new build with the following floor heating manifold: https://www.robotclimate.com/media/amasty/amfile/attach/c9864db4135c6f26c6d9e41254816317.pdf
In particular, I have the "District Heating PRO manifold" (Section 3.2).
I also have district heating from Ennatural, and PVC floor.

I have some questions to understand how the system works so that I can regulate it properly.

1. I understand that with the B knob I can control the temperature of hot water going into the floor. For now, I set it to 35C, which means that the water will flow under the floor at that temperature. But it doesn't mean that 35C will reach the "manifold" (it will be around 65C according to Ennatural). Correct? That would explain why the temperature gauge (F) goes beyond 35C when the heating is operating.
2. I understand that with the M knob I can control the return temperature. I always put it at the maximum (5), which means that the maximum return temperature is of 50C. However, in my short experience, it never goes beyond 25C, and actually it is stable there. I think that this is normal since the supply temperature is of 35C, correct?
3. According to Ennatural (Section 2.1 of ennatuurlijk n Standaard Conditions Binnen Installaties.pdf), I must supply return water with a temperature between 30 and 35 degrees . But I believe I never went above 25C... And even if I were able to reach higher temperature, should I set the knob such that it will never deliver a return above 35C? I guess this means setting the knob at level 2?
4. Is 35C temperature okay for PVC floor, or what is a good temperature?
5. What would the right return temperature be?
6. How do I turn off the floor heating (besides using the thermostat)? Do I need to set the B knob (supply water temperature) at low temperature (below 20C)? Or do I need to set the M knob (return temperature) at level 0?
7. The water pump is set at speed 1 (out of 3) with constant differential pressure. is this ok?

Thank you!

 

[The headhunter]

1 supply flow will be 65 till 90 degrees, as it enters the manifold it gets mixed with a part of cold returnflow water to get down to the desired circulation temperature.

2 is de maximum setpoint return flow temperature, set it at 35 degrees.

3 Water return flow max 35 degrees, higher is not allowed. The lower the better.

4 you shoud ask the supplyer of the pvc floor.

5. Returnflow is ca 5 degrees lower as supply setpoint with a warm floor, if the floor is heating up the difference will be higher, thats no problem.

6 normally you control the unit bij thermostat.
If you turn de knop to 0 the supply is cosed and the floor heating off.

7 constant diff is ok. 1 2 or 3 is dependend on flow.
Speed is normally calculated to get the optimum flow trough the floor of ca 2l/min/string.
But if the floor is comfortably evenly warm don't change it.

 

[PierpaoloB]

Thank you!

I still have few questions:

1. In theory I can set the supply temperature to a bit above 55C and the return temperature to 50C. I'm not going to try, but let's say that this works and I'm supplying return water to 50C. This is above the Ennatuurlijk limit of 35C. What will it happen? Will I receive an angry call from the provider?
2. What is the point of setting the return temperature? If I set the supply temperature to 35C, I will never be able to return more than 35C. Is this setting for "protection"? For instance, (as above) if I set the supply to 55C, then I need to set the return to 35C.
3. Is there a benefit of setting the return to lower than 35C? Let's say that I set the supply to 35C (or higher) and the return to 20C. What would happen in this case? Will it work? Is it better?

Thank you!

 

[The headhunter]

1 sometimes nothing will happen, sometimes a technician can report.it.during maintanance.And your meterset can compensate for high return.

2 its a safety and setting it wrong can lead to high energy costs.
And why would you tamper with it, you do not gain anything.

3 no, setting it to low results in a cold floor as the water must cool down to 20 degrees bevoor the valve opens en lets cold water out, and if no water gets out no hot water gets supplyed to the manifold tesulting in a cold floor.

Set supply to 30-40 max, return at 35.
And just leave it allone.
Its not an system that needs constant monitoring and ajustment.
Your thermostat controls the energy supply when needed.

 

[PierpaoloB]

Clear, thanks!

Just one last question about the M knob (return temperature).
The datasheet of the manifold says that it can be used to regulate the return temperature from 20 to 50C.
If look at the knob, there are 5 levels (from 0 to 5), hence I would think that each level increases the temperature by 6C.
For instance: level 1 -> 26C, level 2-> 32C, ..., level 5 -> 50C.
That makes sense, but I've also noticed that there is a "frost/ice symbol" before level 1, and usually the frost symbol indicates a temperature of 7C (and not 20C or higher).

So the question is: at which level should I set the return knob?

 

[The headhunter]

You should contact the manufacturer of the knob for a datasheet is not universal.