Gas boiler lobby obstructing heatpumps

[HughF]

22 minutes ago, Beelbeebub said:

Yes,.but I meant the "head" units - for air 2 water those are UFH, radiators, maybe fan coils and can be swapped out with other brands, types etc 

 

If your one of your Daikin XYZ2GHP7J2PX (my god the model number system is opaque!) indoor unit dies, I don't want to have to replace it,.the other indoor units and the outdoor unit because getting a compatible replacement is tricky 

 

Especially if the outdoor unit is hard to access.

If you buy daikin, chances are you’ll be able to swap indoor units without replacing the outdoor. For generic Asian units that won’t be the case.

 

A daikin vrf outdoor unit will happily drive wall mount, high-wall, ceiling cassette, or ducted…

[Beelbeebub]

Daikin do the hot water cylinder that acts as a head unit I think. That might be very interesting, especially if it could be added later.

 

I have looked at some courses, how much were you quoted if you don't mind me asking?

Edited August 5, 2023 by Beelbeebub

[HughF]

1 hour ago, Beelbeebub said:

Daikin do the hot water cylinder that acts as a head unit I think. That might be very interesting, especially if it could be added later.

 

I have looked at some courses, how much were you quoted if you don't mind me asking?

They’re all about a grand….

[TonyT]

5 hours ago, SteamyTea said:

Can get an 'evergreen' F-Gas course here, about a grand.

https://fgasregister.com/f-gas-training/

 

There is new legislation about the right to repair coming in.

https://www.bbc.co.uk/news/business-56340077

 

The biggest issue, as usual in the UK, is planning law and implementation.

You can forget all the rest, until that is sorted, it will be impossible to install ASHPs in too many locations.

The Government has a target of 600k/year, but last year we installed 60k, bet most were on new developments.

 

you need to be in the industry to do that course.

[SteamyTea]

4 hours ago, TonyT said:

 

you need to be in the industry to do that course.

Say you are a supplier.

 

[sharpener]

1 hour ago, SteamyTea said:

Say you are a supplier.

 

 

I have wondered about doing one of various HP courses e.g. this one from NAPIT, £550 looks very reasonable for a 3-day course.

 

However like most of the others it requires a daunting array of preconditions including 3 yrs industry experience and a Water Regs certificate.

 

Whether they would in practice turn down the extra £550 is another question.

 

Edited August 5, 2023 by sharpener

[HughF]

13 hours ago, TonyT said:

 

you need to be in the industry to do that course.

My mate is a project manager, he’s just done it. You don’t need any pre-requisites, unlike g3.

[HughF]

8 hours ago, sharpener said:

 

I have wondered about doing one of various HP courses e.g. this one from NAPIT, £550 looks very reasonable for a 3-day course.

 

However like most of the others it requires a daunting array of preconditions including 3 yrs industry experience and a Water Regs certificate.

 

Whether they would in practice turn down the extra £550 is another question.

 

I wouldn’t bother with that, it’ll be really un-technical. 

[Beelbeebub]

Just on the topic of HP's and undersized cylinder coils.

 

Came across this plot of an Arotherm+ (r290) system.

 

It's doing a legionella cycle and the outside air temp is 10-15C over the cycle.

 

As you can see it tops out at 75C where the CoP is a little under 2. At this point it's about on parity with a gas boiler for primary energy (gas burned) efficency.

 

But running at 65C the CoP is 2.4, very much ahead of a gas boiler.

 

Clearly this is a well set up system and the cylinder probably a fairly big coil.

 

But if we had a smaller coil and had to run at high temps throughout the cycle it would be possible.

 

[MikeSharp01]

That's interesting data.  I am curious about the steps at about 09:15 - 09:25 the trends carry on but are stepped lower, does the machine decide it is approaching setpoint and back off (Modulate down)? It does slow  It does look like it could get the Flow even higher, for a lower CoP. Have added a few, very crude, lines to help me get it all in my head. I appreciate that the two trends (Power in / Power Out) won't ever meet but I thought is was interesting to see where they are going!

 

[DanDee]

9 minutes ago, MikeSharp01 said:

That's interesting data.  I am curious about the steps at about 09:15 - 09:25 the trends carry on but are stepped lower, does the machine decide it is approaching setpoint and back off (Modulate down)? It does slow  It does look like it could get the Flow even higher, for a lower CoP. Have added a few, very crude, lines to help me get it all in my head. I appreciate that the two trends (Power in / Power Out) won't ever meet but I thought is was interesting to see where they are going!

 

another example to study

 

https://emoncms.org/app/view?name=MyHeatpump2&readkey=0c28f25dea9e38f983d9c83a6dd455c0

 

[SteamyTea]

6 minutes ago, MikeSharp01 said:

I am curious about the steps at about 09:15 - 09:25 the trends carry on but are stepped lower,

They coincide with the 'heat' plots.

What are the heat plots actually measuring?

 

When dealing with thermodynamics, nothing is a straight line, even if it looks like it sometimes.

Using my very favourite equation e^kt, it is only when k is set to 0, or infinity, that you get a strait line.

 

[SteamyTea]

2 minutes ago, SteamyTea said:

What are the heat plots actually measuring

 

4 minutes ago, DanDee said:

another example to study

Right, quite correctly, 'Heat' is energy.

[Beelbeebub]

1 hour ago, MikeSharp01 said:

That's interesting data.  I am curious about the steps at about 09:15 - 09:25 the trends carry on but are stepped lower, does the machine decide it is approaching setpoint and back off (Modulate down)? It does slow  It does look like it could get the Flow even higher, for a lower CoP. Have added a few, very crude, lines to help me get it all in my head. I appreciate that the two trends (Power in / Power Out) won't ever meet but I thought is was interesting to see where they are going!

 

My guess is that the pump was unable to eject enough heat to the cylinder at the deltaT between the 75C flow and cylinder temp, which would have led to an unacceptably high system temp and pressure.

 

So it modulated it's speed down so the power output was lower with the same flow temp IE lower water flow rate.

 

This allowed it to continue operating, but at a lower COP.

 

All a bit of guesswork tho.

[MikeSharp01]

1 hour ago, SteamyTea said:

When dealing with thermodynamics, nothing is a straight line, even if it looks like it sometimes.

Using my very favourite equation e^kt, it is only when k is set to 0, or infinity, that you get a strait line.

You are right but PowerPoint, that I used to add those trends, only really  does straight lined. I hated thermodynamics at Uni - I only did one course and decided my future did not lay in that direction so steered well clear. Even though now it might have been useful I wouldn't have wanted to clutter my brain with it for 40 years only to find it useful now! Respect to those that get it though🤩

[sharpener]

28 minutes ago, Beelbeebub said:

My guess is that the pump was unable to eject enough heat to the cylinder at the deltaT between the 75C flow and cylinder temp, which would have led to an unacceptably high system temp and pressure.

 

So it modulated it's speed down so the power output was lower with the same flow temp IE lower water flow rate.

 

This allowed it to continue operating, but at a lower COP.

 

All a bit of guesswork tho.

 

That seem a good explanation.

 

But what are the spikes in heat o/p at 0850 and 0905, there a corresponding dips in the F & R temps but nothing on the elec consumption, what is going on here?

[SteamyTea]

44 minutes ago, MikeSharp01 said:

only really  does straight lined. I hated thermodynamics at Uni - I only did one course and decided my future did not lay in that direction so steered well clear.

Oddly, I found it pretty simple and basic, very mechanical in nature.

But most physics is mechanical.

Maybe there needs to be some new SI units that take into account opinion and bullshit.

[JohnMo]

I enjoyed thermodynamics at HNC level and at degree level until the exam. Completely messed up the exam at degree level. So was dropped after that.

[SteamyTea]

17 minutes ago, JohnMo said:

Completely messed up the exam at degree level.

I had the same with a statistics exam, sat there feeling like an abandoned 5 year old at primary school.

Amazed everyone how I completely flunked it.

[DanDee]

1 hour ago, sharpener said:

 

That seem a good explanation.

 

But what are the spikes in heat o/p at 0850 and 0905, there a corresponding dips in the F & R temps but nothing on the elec consumption, what is going on here?

That's when you use the hot water from the tank.

[Beelbeebub]

4 hours ago, sharpener said:

 

That seem a good explanation.

 

But what are the spikes in heat o/p at 0850 and 0905, there a corresponding dips in the F & R temps but nothing on the elec consumption, what is going on here?

At a guess, there was a transient (eg water pump and/or compressor speeds changed) at that point, that confused the heat meter. it doesn't affect the total heat quantity delivered because the spike is relatively short, but does muck up the instantaneous reading.