@derek-m morning! I am just having a look at all the flow rates for the system as you advised. None of them are set to above 2 at the moment. Once I have identified the coldest rooms, am I aiming to have the flow rate to these rooms at the max of 6 and then adjusting the flow to the others accordingly? If I understand it right, I should then be able to reduce the flow temp on the weather compensation? Thank you!
Hi Curly,
I'm afraid that I have never had an UFH system, so I am having to make certain assumptions as to what will occur as you make adjustments.
The first thing is to record the setting of each flow regulator, just in case you need to reset any to their original setting.
On your system there are 18 flow regulators, which if they were all set for the maximum flow of 6 litres per minute, would equate to a total flow rate of 108 litres per minute, which it is impossible for your water pump to supply. Dependent upon the operating conditions, the total flow rate around your system could be in the range 10 to 30 litres per minute. So if you increase the flow rate through one of the flow regulators, it is very likely that the flow rate through one or more of the other flow regulators will be reduced slightly. This is why the balancing process can take some time to achieve.
I would suggest slowly increasing the flow rate through the flow regulator for the coldest room, and noting the change in flow rate shown by the red indicator. You may find that at a certain position, there is no further increase in indicated flow rate, as the flow regulator is opened further. This would indicate the maximum flow rate through that UFH loop under the present operating conditions.
I forgot to ask if any rooms have more than one UFH loop and therefore more than one flow regulator?
Once you have fully opened the flow regulator or regulators for the coldest room, it is then necessary to monitor the room temperature and note the effect. If the room temperature increases, then the weather compensation curve can be adjusted to reduce the LWT from your heat pump.
Once the desired temperature has been achieved in the coldest room, it is then a matter of adjusting each flow regulator or regulators for each of the other rooms, to once more achieve the desired temperature in that room. Obviously, as you reduce the flow rate to some of the warmer rooms, this may in turn increase the flow rate to the other rooms, hence increasing their temperature slightly. I suppose this is why it is referred to as 'balancing'. 😎
@derek-m thanks for your reply. I have increased the flow to the coldest room and it goes up to 2 at max. Will monitor the temp over the next couple hours and see how we go! yes- a few of the rooms do have 2-3 flow regulators.
to the side of the UF heating manifolds there is a gauge you can turn with temps on it- I think you may have previously referred to it as a mixer (I’ve attached a pic)? I’ve noticed upstairs it’s set to 45 and downstairs 50- does this matter?
With regards to the weather compensation I am still a bit confused with the controls on the Midea panel. If I click through to weather compensation it has 2 options- ‘zone 1 high temp mode’ and ‘zone 2 low temp mode’. At the moment I have just turned on the ‘zone 1 high temp mode’ and chosen one of the curves that correlate to the manual but not sure if this is right? The low temp curve options in the manual seem like the flow temp is quite low… It’s really not clear in the manual- any ideas welcome!!
@derek-m thanks for your reply. I have increased the flow to the coldest room and it goes up to 2 at max. Will monitor the temp over the next couple hours and see how we go! yes- a few of the rooms do have 2-3 flow regulators.
to the side of the UF heating manifolds there is a gauge you can turn with temps on it- I think you may have previously referred to it as a mixer (I’ve attached a pic)? I’ve noticed upstairs it’s set to 45 and downstairs 50- does this matter?
With regards to the weather compensation I am still a bit confused with the controls on the Midea panel. If I click through to weather compensation it has 2 options- ‘zone 1 high temp mode’ and ‘zone 2 low temp mode’. At the moment I have just turned on the ‘zone 1 high temp mode’ and chosen one of the curves that correlate to the manual but not sure if this is right? The low temp curve options in the manual seem like the flow temp is quite low… It’s really not clear in the manual- any ideas welcome!!
Hi Curly,
With UFH systems damage could occur to the flooring if the water temperature gets too high, so a method to limit the water temperature had to be implemented. This is the secondary water pump and temperature controlled mixing valve, which is designed to mix some of the cooler water coming back from the UFH loops, with the hotter water coming from the boiler or heat pump in your case.
Such a system is much more important with a gas or oil fired boiler, where the outlet water temperature could be 70C or higher. I would question the need for such an arrangement when the heat energy is supplied by a heat pump, operating at much lower temperatures.
The way that your system is designed to operate is as follows:-
The warmer water from your heat pump enters the mixing valve at the left-hand side port, it then flow out of the top port to the secondary water pump, which pushes it into the upper header supplying the flow regulators feeding the UFH loops. The return water from the lower header is piped to the right-hand port of the mixing valve, and flows out of the bottom port back to the heat pump for re-heating. If the water coming into the mixing valve is warmer than the setting on the dial, the mixing valve starts to open to allow some of the cooler return water to be mixed with the warmer supply water, and hence limits the temperature of the water going to the UFH loops.
Since the objective is to operate your system in the most efficient manner, with the lowest LWT, the mixing valves should remain closed at all times.
For the rooms with more than one flow regulator, try to adjust each one so that they all have approximately the same flow rate.
There are a number of forum members such as Batalto and CathodeRay who I know have Midea heat pumps. They will probably be better able to advise on how best to actually adjust the WC curve. There could also be some YouTube videos available, providing step by step instruction. The objective is to try to select the curve which closely matches the heating demand of your home.
@derek-m many thanks for your reply and all your help to date! That makes a lot more sense. Will see if I can find anything on YouTube and pop a separate question on the forum if I get stuck. Thanks again,
