Very interesting video. The secondary pumps that do this are Magna 3 set to DT control. You need to add a sensor to use this control mode. They are also very useful in more complex systems with plc or ddc control with cim module they play nicely with supervisory control. So you can set limits on low speed / high speed and use DT control in between. Downside is expensive and time consuming to setup!
I fitted one about a year or so ago on DT control. But what we need on heat pumps is to a very the flow according to the cycle. This way we can minimise negative mixing until it is needed to prevent cycling auto charge the buffer prior to defrost
what efficiency losses would be expected from integration of a buffer/LLH ? My stance is the volume of stored thermal exergy would favor the systems performance and comfort at a cost of some efficiency. This is a very good topic 👍
I wouldn't expect the buffer to cause any loss of efficiency. This is because the flow on the secondary side would always be lower than the primary and so the heat pump would never need to run at a higher temperature then required to supply the highest temperature circuit
On most systems which are "open" then no. When people want to make small zones such as a bathroom or utility room then it can create problems where a volumiser or buffer may be needed. Other issues such as different temp circuits then need a buffer or LLH . Not a perfect solution for efficiency but a solution which works.
I'm not sure I entirely follow what you're trying to say. For a system of mixed emitters to be open the underfloor would have to run it significantly higher temperature then I think would be good design practice
I am not sure I follow you! What I am trying to say is when there are too many actuators and thermostats fitted it can make small zones with little volume. heat pump compressors don't like this at the dt can't be maintained between 5 and 7 degrees and often the heat pumps will go into fault. With the mixed circuits I am referring to radiators being run at say 45 degrees and underfloor at a lower temp. The best scenario is to have larger radiators so that all can be run at say 40 degrees if possible.@@andrewmillwardwatford9410
Hi Andrew, I like your videos. I've done HG and kimbos training. However, where are you learning hydronics. I ask as I really want to have a huge understanding of this. Any literature you can recommend, please let me know. Good videos
@@brotherjohnno yes it's no problem at all most Sunday mornings at 10:00 a.m. until I get too tired to continue or you have to leave just private message me to confirm an event is being held
Hydraulic isolation with a heat pump would definitely add some inefficiencies and does the heat pump separates the refrigerant from the system water via a plate heat exchanger I'm not sure it's needed. I think in the future we will be unblocking the plate heat exchanger in heat pumps by flushing out this heat pump with acid cleaners but leaving it in situ in the heat pump
It is important (for resolving the arguments) to first define an initial operating scenario and layout, and then locate the 'bottleneck' in the flow/temperature calculations. i.e. which aspects is the critical limiting factor (temperature and flow at each heat emitter). Given that initial scenario, this would indicate which other circuits need [basic] 'throttling'. Now we hit the "however". We start to look at the other scenarios that we will also have to operate under, and see if any other those alternate scenarios shift the bottleneck and hence the that the throttling would need to shift locations. It's at this point you start to look at all the 'magic' controls and flow limiters and diverters and other cheap and not so cheap methods (and the style of intelligence of the designer ('use what you know' vs 'learn something new' ;-) ). Finally, realise that the old ways of doing things were for 'older properties with older limitations'; we're going to have to do things different in the NWO (new world order;-)
Hello mate. I’ve not heard anyone suggested ufh and rads on the same system with different design temps without separation. Most people I’ve heard are suggesting designing rads and ufh to the same temp if trying to avoid separation. I agree, even separation is just used to overcome head issues, a system that matches heat pump circulation pump flow rate to distribution pump flow rates would take all the issues of distortion out of the way.
Confusion haha that the word I am after Heat Pumps hide behind confusion.How do you control Flow Rate it is a mechanical valve set and forget pumps have 3 speeds that is not volume litres per minute is a variable depending on outside temperature is it not.Said wee Jimmy at the back of the class.I am passing the time trying to figure it out.Cheers good content can’t keep them all Happy haha.We don’t all have money to throw at it you must have a cheap pump .your installer was crap,your low loss calculations are wrong take your pick they all apply.
