@jamespa 

Controlling the Flow rates of the Heat Pump water pipe and the Radiator Water Flow

I have, currently, a separate control for the Heat Pump Water flow AND the Radiator Water Flow.

Each Water Flow Pulse Width Modulated Control is really only a single output pin on the "Arduino".

The "Arduino" has a one line instruction allowing selected output ports to act as PWM sources.

The "Arduino" drives the two Pulse Width Modulated  motors flawlessly.

Your point about "Short Cycling" is well made.

To increase the cycling period I have reduced the Flow rate, and therefore power, when the Water Temp exceeds a set Temperature.

Below this set Temperature the Water flow remains at a maximum flow rate.

Above this set temperature,  the Flow rate is reduced,  further reducing  the power , and , increasing  the Cycle time.

ian

@jamespa 

The Elephant in the Room ...................................The Heat Pump Refrigerator

Heat Pump Diagnostics ?

Many complex devices have Diagnostics to try and find "difficult faults", ( well sometimes !)

My Outdoor Samsung Heat Pump comes with it's own Diagnostic test built into the controller.

Two Diagnostics are available:

1 ) Heating Diagnostics

2) Freezing diagnostics.

Both Diagnostics run flawlessly for about 15 minutes , however, I do not know the meaning of the results!

For example: What is Order or current Frequency?

What are Evaporator steps ?

Does anyone know where these terms are explained ?

Have I passed these Diagnostics .....or Not?

ian

@iantelescope

If it works, and it sounds like it does, that's great.  The only things to remember are that the rads/pipework are probably designed for DetlaT of 5 (not that it makes much difference as pointed out above), and the HP ditto.  Some heat pumps (eg LG) have different max/min amounts of heat they can deliver at different flow rates, not sure why, I presume its where they are working at the edge of what the heat exchanger (inside the HP) can do.

I strongly suspect many installers just fit the pump without adjusting it or adjust it until they can feel a slight temp difference across the radiators ('by feel' is an accepted way to balance I believe).

I am sorry to say that, after my 2 year journey, I have absolutely no respect for MCS at all.  Its far too dominated by the industry, and I suspect that that is mostly the grant harvesters (I do have a list of names so one day I might check).  It has written itself into PD rules and thus created a closed shop, and its decision making processes are opaque and minutes of the meetings of the working groups who write the rules (which, because their rules are written into PD, are effectively making law of the land) are not published. 

Following the rules set out in the relevant documents (which are published) I actually applied to join the working group, offering to be an intelligent consumer voice.  Guess what, they didn't follow their own published rules when they rejected my application (the rejection was effectively for a whole class of people, basically consumers, not me specifically).  Out of 40 members only three 'represent' consumers, they are a representative of Citizens advice, a representative of the Energy Saving Trust and some guy from an renewables consulting firm.  Frankly I doubt they know anything about the practical customer experience.

I have even less respect for the Government which has encouraged this to happen.

@jamespa 

NIC,MCS sand RECC.

The NIC have refused to allow "any photographic or recording device" when they visit for the inspection of my Heat Pump".

If "any recording device is discovered their inspector will "terminate the inspection".

Why?

ian

Posted by: @iantelescope

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@jamespa 

 

NIC,MCS sand RECC.

The NIC have refused to allow "any photographic or recording device" when they visit for the inspection of my Heat Pump".

If "any recording device is discovered their inspector will "terminate the inspection".

 

Why?

 

ian

 

 

Their inspector is obviously very shy, or is so young that you would not be allowed to take their photo without their parents permission. 😋 

@iantelescope  I would say that that is very underhand and stinks of duplicity! As a retired sound technician / engineer, I know that a sound record can be ‘re-arranged’ or edited to appear to relate a different event altogether; however, (and this is the only reason I can think of) to disallow any recording from being made suggests that they suspect you of duplicity from the ‘get-go’! This is underhand and hardly a good spirited approach to resolving an enquiry that has been made in good faith and as far as I can see, without any signs of antagonism towards the installers or manufacturers. What has happened to any genuine approach to resolve a possible shortcoming in installation or design? Should these groups not be demonstrating a real desire to resolve the matter and strive for improvement for you and the future of the product??? Sorry, I’ll get down from my soap box now, but such an approach would rile me to say the least! Regards, Toodles. 

@derek-m Can’t be too careful these days 😉 Toodles.

Posted by: @iantelescope

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@jamespa 

 

 

The Elephant in the Room ...................................The Heat Pump Refrigerator

 

 

Heat Pump Diagnostics ?

Many complex devices have Diagnostics to try and find "difficult faults", ( well sometimes !)

 

My Outdoor Samsung Heat Pump comes with it's own Diagnostic test built into the controller.

 

Two Diagnostics are available:

1 ) Heating Diagnostics

2) Freezing diagnostics.

 

Both Diagnostics run flawlessly for about 15 minutes , however, I do not know the meaning of the results!

 

For example: What is Order or current Frequency?

What are Evaporator steps ?

 

Does anyone know where these terms are explained ?

Have I passed these Diagnostics .....or Not?

ian

Current Frequency could be in relation to the compressor speed, since it is controlled by a variable frequency drive.

Evaporator Steps may relate to the valve controlling the refrigerant flow through the evaporator which is often positioned by means of a stepper motor.

I would not get too tied up with the diagnostics unless they should indicate a problem. At the moment your priority should be to get your system correctly installed and optimised for most efficient operation.

@derek-m 

Where to position a buffer tank for "short Cycling" ?

1) Do I position the Buffer "in Series " with input to the Heat Exchanger after the Three way valve? (Samsung,  Midsummer, Hendra ....)?

This position is very difficult to fit the pipes into the spiders web of pipes currently surrounding my Cylinder !

2) Do I position the Buffer "in Parallel " with Heat Pump Water feed  ( Hendra ....) ?

This position is recommended by Hendra when no Heat Exchanger is fitted.

The Buffer here  presents a very low resistance to the water flow thus "partially shorting the Heat Exchanger".

The Buffer resistance can be increased using the valve connected in series with the Buffer, thus increasing the water flow to the Heat Exchanger.

3) Where to position a buffer tank for storage during "Winter Freezing" ?

Do i position the Buffer in series with the Water return pipe , as recommended by Samsung , Hendra and midsummer?

4 ) Where to position the Buffer for BOTH Short cycling and Winter Freezing ?

ian

Posted by: @iantelescope

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4 ) Where to position the Buffer for BOTH Short cycling and Winter Freezing ?

In the return, two pipes only.  All it does is increase system volume.  By putting it in the return not the feed its at a slightly lower temp, which slightly reduces its effectiveness against freezing but doesn't affect its effectiveness in terms of system volume/short cycling and guarantees not to reduce FT to the emitters (which is the thing to be avoided at all costs). 

I have never heard of putting it in parallel with a HEX, that makes absolutely no sense as far as I can see unless someone can correct me.

In the feed (option 1) is OK, but it will be hotter so will lose a bit more heat to the room.  In the return is, so far as I know, optimal.

Posted by: @derek-m

↑

Posted by: @iantelescope

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@jamespa 

 

NIC,MCS sand RECC.

The NIC have refused to allow "any photographic or recording device" when they visit for the inspection of my Heat Pump".

If "any recording device is discovered their inspector will "terminate the inspection".

 

Why?

 

ian

 

 

Their inspector is obviously very shy, or is so young that you would not be allowed to take their photo without their parents permission. 😋 

 

My garage takes a video when it does its service.  I've never bothered to watch thus not sure if the employee can be identified.

@jamespa 

Thanks James.

Positioning  a two port Buffer across the Radiator circuit is promoted by Kendra in his excellent  "Buff up your knowledge of buffer tanks "

see attached pdf.

This presumably only works where the parallel pipes have a lower resistance compared to the Buffer itself.

If, when using a Heat Exchanger , the Buffer resistance was increased , the Water would flow through the Heat Exchanger and the Operational volume would be increased by 50 l.

ian