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!
@andrewmillwardwatford9410
4 күн бұрын
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
@bampot2241
2 ай бұрын
Brilliant video Andrew!!
@normanboyes4983
2 ай бұрын
Let me just declare right now that I am confused and my brain has just tripped the supply breaker.😉
@tomsullivan835
2 ай бұрын
I think that Stielbel we looked at had independent pwm control for the external pumps on the system.
@henrybartlett1986
2 ай бұрын
As always, thought provoking and pertinent.
@andrewmillwardwatford9410
2 ай бұрын
Thank you for your compliment
@EliteHydronics.
2 ай бұрын
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 👍
@andrewmillwardwatford9410
28 күн бұрын
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
@johnnyfandango1625
2 ай бұрын
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.
@andrewmillwardwatford9410
2 ай бұрын
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
@carlwhitaker5151
2 ай бұрын
Could you not design the radiator circuit and underfloor heating to work at the same temp?
@andrewmillwardwatford9410
2 ай бұрын
If you watch the video again you'll see that I address this issue
@johnnyfandango1625
2 ай бұрын
Yes@@carlwhitaker5151
@johnnyfandango1625
2 ай бұрын
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
@philipoakley5498
2 ай бұрын
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;-)
@andrewmillwardwatford9410
2 ай бұрын
The same design tools will apply to any scenario and the same fixes would be applicable you are the live with poor control or you design good control
@CommercialGasEngineerVideos
2 ай бұрын
Good question. Lets see what professor Andy has to say on the matter.
@andrewmillwardwatford9410
2 ай бұрын
I think there's going to be more where this comes from
@danielbailey6745
2 ай бұрын
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.
@huyongquan6554
2 ай бұрын
I think there should add hydraulic isolation for discussion due to system service and economical.
@andrewmillwardwatford9410
2 ай бұрын
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
@christianstewart09
2 ай бұрын
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
@andrewmillwardwatford9410
2 ай бұрын
Where are you based in the country?
@christianstewart09
2 ай бұрын
@andrewmillwardwatford9410 Devon but always keen to learn and travel
@andrewmillwardwatford9410
2 ай бұрын
@@christianstewart09 it's a shame you're so far away as I run events at my home on Sunday mornings to discuss hydraulic design
@brotherjohnno
2 ай бұрын
Hi Andrew, would it be possible to come along to one of your future events?
@andrewmillwardwatford9410
2 ай бұрын
@@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
@giuseppe072000
2 ай бұрын
I use Chinese HP who have controll for another PWM pump and another AC normal pump with 2 temperature sensors
@andrewmillwardwatford9410
2 ай бұрын
That sounds interesting what make are the Heat pumps
@giuseppe072000
2 ай бұрын
When flow temperature is below 15C it necessary more water / energy in the system
@andrewmillwardwatford9410
2 ай бұрын
I'm sorry I don't understand what you're trying to say
@normanboyes4983
2 ай бұрын
When the flow temperature is below 15C you are cooling the rooms.
@giuseppe072000
2 ай бұрын
@@normanboyes4983 15C is flow temperature for 1 minute at defrosting ....in winter
@normanboyes4983
2 ай бұрын
@@giuseppe072000 Well that is hardly worth bringing up to be honest - it’s a mere transitory condition.
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