Tado urgently needs the certificate for intelligent "hydronic balancing" (Germany)!
In Germany, switching from fossil fuel heating systems to environmentally friendly heating systems is massively subsidized by the government. One criterion for receiving this subsidy (e.g. 55% of the investment sum!!) is the requirement that the heating system in a house is optimized by means of so-called “hydraulic balancing” (hydraulischer Abgleich). In order to receive the subsidy, you must provide a certificate that this balancing, which costs up to € 1000.– has been carried out by a specialist company.
This balancing can also be achieved using intelligent radiator valves. Manufacturers other than tado already have certification that saves the customer up to € 1000 when buying valves from competitors.
==>> Tado absolutely must also apply for such a certificate (e.g. TÜV Rheinland) and thus add a further massive highlight to its product range. This is a very strong argument for choosing tado - or another provider that can already provide its customers with this certificate.
Johannes
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My understanding of Tado functionality is that it does not perform a balancing function.
In the UK we have the SRT/TRV at one end of the radiator and at the other end of the radiator there is a "lockshield valve". The lockshield valve can be adjusted in order to regulate the maximum flow rate through the radiator, but it's designed to be left alone once set up correctly. It's purpose is to ensure that all radiators get a fair share of the water flowing through the system by throttling the flow through the radiators closest to the boiler and allowing some water to be diverted to other radiators further along the pipework.
The SRT does not function in this "balancing" fashion. The radiators closest to the boiler will always have higher priority (first come, first served) over those further away, and those distant radiators may have to wait for the early SRTs to close before they see much heat at all. Depending on exactly how you implement Tado on your system it might have a pseudo balancing effect, but if the boiler shuts off for thermal reasons (flow temperature limit) or a boiler run time limit reached before the early radiators are satisfied, those radiators last on the pipe run may be left wanting. This is not how a system is balanced. You need all radiators to have equal opportunity for heat at the same time. That means restricting the flow through each radiator to varying degrees depending on distance along the pipework from the boiler so that each radiator leaves sufficient water to continue flowing beyond to the next radiator and the next radiator and so on.
To visualise this, think of the heating system like a ladder. One ladder leg is the flow from the boiler. The other ladder leg is the return to the boiler. Each rung represents a radiator. As water flows from the boiler the first rung/radiator will short circuit a lot of the water straight back to the return. Any water left over will continue to the second rung/radiator, where again much of it will quickly head back to the return. By the tenth rung/radiator there won't be much left. Thus you must restrict the flow through the first radiator significantly, and the second one a little bit less and so on. SRTs can't do that. They manage their temperature. They don't care whether there is enough water for the next radiator and the next and the next. They take as much as they want, leaving less and less for everyone else. They do not balance the distribution of the water equally/fairly.
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A good and comprehensible explanation and answer. Thank you very much!
For DE at least, there is a lot of money at stake here. I take a somewhat critical view of an overstretched aspect of the whole thing and therefore see it more as “economic aid” (for the trade) than that this public obligation will achieve anything earth-shattering in the area. 1000 € are on the table - for the engineer who carries this out, plus the tinsmith, who may be allowed to replace all radiator valves (not thermostats!), draining the water and re-pressurizing it. Unbelievable, in my opinion.
What doesn't make sense to me is the fact that with our heat pump heating system, the first radiator takes a noticeable long time to reach output due to the low flow temperature. Not because of the water flow, but because of the low flow temperature. If I now also throttle the flow rate because there are 5 other radiators, nobody in the house gets any more heat because everyone only gets a straw of water.
Intelligent radiator thermostats take what they need - but if this is sufficient, they regulate down. We are currently running a two-storey apartment without hydronic balancing, but everyone is happy and everyone has the heat they want.
It is the company homatic IP, which has the certificate in Germany to replace the expensive hydronic balancing. I'd rather spend €1000 on intelligent thermostats than put them in the pocket of a “theoretical” engineer.
Unfortunately, Tado is asleep at this point. That's a great pity. I saw it too late after purchase.
Marry X-mas!
Johannes0 -
I don't have a heat pump, just a conventional condensing gas boiler. However, I do try to operate system in a fashion as though I did have a heat pump.
Heat pump philosophy is to heat the building "low and slow". Unlike a gas boiler, which can output a lot of heat, fast (24 kW max for my boiler) a heat pump only trickles the heat out slowly. It cannot raise temperatures quickly because it doesn't have the power to do so. It needs to be left running continuously, 24x7, with the temperature set back only one or two degrees overnight, if at all. Then, as each day begins, there is only a little bit of extra work required to raise the temperature a degree or two.
I actually have my boiler output restricted to the minimum possible - 9 kW - and it is still too powerful, forcing it to cycle throughout the day (and night). Partly because the output is restricted (and cannot raise temperatures rapidly), but also for efficiency and comfort, the house remains heated 24x7, regulated by the Tado SRTs and only set a couple of degrees lower overnight. That way it doesn't take to long to teach target temperature for the start of the day.0
