TGA planner difficulties, underfloor heating supply temperature + wastewater ventilation

Do you consider it possible to run 40° warm water through the pipes without the surface temperature exceeding 27°C?

There is a calculator online for that. Like the abacus, it just starts with a u.

I have entered some general data. At 40 degrees flow temperature, the surface temperature comes out to 35.6 degrees (60mm screed with 40mm cover, 150mm pipe spacing, and 16mm pipe. So no, that does not work with my sample setup. I think it almost doesn't matter how the setup is and, if necessary, floating parquet is installed, it will nearly always exceed 27 degrees.

if you already have to pay the TGA planner expensively (according to HOAI?), then you can also insist on the provision of services. YOU are the client. He then has to implement your wishes within the framework of the "recognized rules of technology or the DIN regulations". If he does not want to/cannot deliver this, I wonder, what should you pay him for then? Is it really a TGA planning office or rather an employee of the sanitation department? What is the contract structure or what options do you have to change the planner?

Yes, that surprises me too, you pay the TGA planner directly? That of course opens up new possibilities. However, it is then also a strange developer. Is it even a developer? Or a general contractor? Who owns the land now?

I think it almost doesn't matter how the structure turns out and in case of doubt floating parquet is laid, it should almost always exceed 27 degrees.

Thank you. I think I barely passed thermodynamics with a 4.0, but I suspected something similar.

What is the contract structure or what possibilities do you have to change the planner?

It is a purchase from the developer. So I have no options at all and I don't pay the MEP planner fully either. However, it is a small developer who was founded for this project (and maybe a few others). I only pay the MEP planner directly for my change requests or am told by the developer what I have to pay the developer for the additional MEP planning. But that is a lot of money for little work and that is also faulty. Since they deliver such poor work, I dealt with the other issues again and came across the problem with the supply temperature. It is a medium-sized planning office made up of architects, civil engineers, etc. (about 40 employees). There are also the requirements (indoor temperatures, surface temperature etc.). I just want to somehow avoid that they mess up and I have to deal with the consequences afterwards or have the effort. I think maybe he is also talking about heating load (40 W/m²) but you can't be that stupid. I still have a small thing to clarify with the construction manager (who, by the way, has been top so far). Maybe he can just tell me if he has anything on the planning. I have asked the MEP planner for further information.

Yes, I had thought about that too. Was it also a developer project for you and did you receive all the necessary data?

No, we have a general contractor but did not trust the plumber's explanation "we have always done it that way" and commissioned an engineering firm. It cost about €600, but now I have the good feeling that it fits. The general contractor along with the plumber looked a bit strange, but it will be implemented that way.

As always, nonsense. There are no general distances and heating circuit lengths. It always depends on the individual case: ratio of envelope area to underfloor heating area, insulation standard, number of windows, floor covering, pipe diameter, room temperature, supply/return temperature difference, electric bathroom heaters. Then VA20 is also possible or VA5 with 130 meters length with acceptable pressure loss and low supply temperature.