"Can you define "Short Cycling"?

Is this short Cycling , acceptable , during April , during the prime Short cycling month of April?"

Unfortunately there is no definitive answer to this but, as @derek-m says 6 times per hour, a 10 min period, is the frequently quoted rule of thumb, which probably dates from times prior to inverter driven compressors which have a slow start up reducing wear, thus I have absolutely no faith in it!  It's the same problem in modelling terms as on/off operation, so at present I don't know of any actual quantitative results.  John Cantor does discuss it on his YouTube videos and does a bit of quantitative work on a couple of examples.

In qualitative terms, if it's cycling when it's 7 ish or less outside, either you have a problem or your system is oversized or you should probably open up some more trvs and maybe run at a lower flow temp.

If it's cycling at 15+, then that's no surprise at all.

If it's cycling at zub zero temps you have a serious issue.

And some long cycling, due as much to load variations as the OAT changes, are perfectly fine.

As a warning, it's very easy to overthink heat pumps and become a bit obsessed with them.  I should know!  If you get the basics right as I and others have suggested, you will be in a much better position.  So if I were you I'd concentrate on this before anything else, for the benefit of your own sanity.

@derek-m 

Many Thanks Derek.

My Water Law settings are :

The Water Law Graph is defined by several bits in the Samsung Controller memory.

The Offsets, above and below the central Water Law graph,  are set by the Samsung Front panel Thermostat.

Because the outside Temperatures are currently 23 C the Heat Pump is inactive.

As James says, I am becoming obsessed with Heat Pumps ...............

Time for a break from Heat Pumps!

Many thanks !

ian

6 times per hour? How about "6" times per day?

https://emoncms.org/samsung5kw

Posted by: @fazel

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6 times per hour? How about "6" times per day?

https://emoncms.org/samsung5kw

-- Attachment is not available -- -- Attachment is not available --

With an OAT of 5C which is what the graphs say you have, you would indeed expect that or better.  Remember that cycling occurs when the heat pump cant modulate down to match the load.  At 5C it can, unless its been really badly over-sized.

Posted by: @jamespa

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Posted by: @fazel

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6 times per hour? How about "6" times per day?

https://emoncms.org/samsung5kw

-- Attachment is not available -- -- Attachment is not available --

 

With an OAT of 5C which is what the graphs say you have, you would indeed expect that or better.  Remember that cycling occurs when the heat pump cant modulate down to match the load.  At 5C it can, unless its been really badly over-sized.

 

At higher outdoor temps it just runs less often.

@fazel

Do you have any thermostats controlling your system?

Posted by: @derek-m

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@fazel

Do you have any thermostats controlling your system?

@fazel

So I assume that your heat pump is being operated in the same manner, which goes to prove that optimisation of your particular system is key to achieving best overall thermal efficiency.

Posted by: @derek-m

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@fazel

So I assume that your heat pump is being operated in the same manner, which goes to prove that optimisation of your particular system is key to achieving best overall thermal efficiency.

That's universally agreed, that optimisation of a system is key to achieving best overall efficiency.

Optimisation should start before the quote is accepted, not after the start up of the system.

@fazel

I fully agree, if the system design is correct then optimising the operation of the system is much easier. The problem is that I suspect that most customers, either don't have the technical knowledge and information to be involved in the design, or since they are paying for a 'system designer' to do this work then why should they have to get involved.

It would appear that many installers also don't have the ability or inclination to fully optimise a system once it has been installed.

Doesn't bode well for the future.

@fazel 

fazel, I am green with envy.

If only I could get Six cycles per day !

I have a system that was NOT designed , but , chosen because my "installer" discovered a  cheap Heat Pump in the  local outlet of a large Plumbing supplies Organisation.

Unfortunately, the Heat Pump came with an Heat Exchanger which my "installer" proceeded to ignore .

Do you have an heat exchanger ?

Do you have a Buffer ?

ian

@derek-m 

Yes Derek, I agree with you .......... I should have Designed my Heat Pump myself. 

External pipe Temperature Sensors?

The Only affordable sensors appear to be K type sensors which attach to the outside of the copper pipes.

This external temperature sensing can be inaccurate if not very inaccurate with the Temperature measurement being the Temperature of the copper , not the water!

Internal pipe Temperature Sensors?

These Sensors appear to be very accurate, judging by my experience with my German "Sharky".

Excellent but completely unaffordable.

How do you measure internal water Temperatures?

ian