ASHP SCOP=3 in uninsulated 1960s house!

[richi]

Notes from video description and nuggets buried in comment replies:

• SCOP 2.99; "very small radiators, no cavity insulation" (but some attention to air tightness I suspect).
• "Vaillant Arotherm Plus. The load is about 6 kW … 22mm pipe." (He thinks the Vaillant HPs are much better than Mitsubishi, but more expensive.)
• "It was a pretty much consistent 21c internal temperature internally all week."
• "Weather compensated … curve selected is set for around 55c at -1."
• "I think once this has sensible radiators the SCOP will be more like 5."
• "Run 24/7 … set back overnight at 18c … does not turn off but lowers flow temp."
• "Electrical consumption in Dec … 580 kWh"
• Any TRVs left on max, ASHP modulates the flow temp down to what's required to maintain room temp. 
• "I have not, nor will not state that insulation isn't the first most important step. By releasing this video I am not saying technology first. … We did not insulate first as this is not a house. This is a showroom. The heat pump will return before insulation and insulation does not fill the showroom."

 

Sorry if you've seen this before. Sk8rboi has some other good content in the channel.

 

 

[Dan F]

47 minutes ago, richi said:

• "I think once this has sensible radiators the SCOP will be more like 5."

 

Not going to happen IMO.  Might get COP of up to 5 if radiators are made large enough to run at 35, it's 10C+ outside and ASHP is running at max 60%.  But that doesn't translate to SCOP of 5!

[SteamyTea]

I am awaiting @Dave Jones to comment, I am sure his input will shed light on it.

Until then, one question?

Does this installation do the DHW?

[Carrerahill]

2 hours ago, richi said:

• "Electrical consumption in Dec … 580 kWh"

£156 a month on electricity for heat alone at my price as of 1st April (so I will be submitting some high meter reads for this month and next).

 

It is not terrible I suppose, but it is not good. 

 

Installation seems flawed, uninsulated house with those little radiators? In new build developments with all their insulation we are seeing little 3500BTU rads and that includes a percentage of space for the calculated space heat loss and was based on a delta of 60°. I just can't see how that stacks up. 

 

 

 

 

[joth]

Regarding the question in your xpost, I would imagine ASHP are classed as "generation" because HM Government classes them as this, by including them under the "Micro-generation certification scheme".

see

https://sustainablebuild.co.uk/what-microgeneration/

https://www.heatpumpsource.co.uk/blog/microgeneration/

 

etc

 

[richi]

On 22/02/2022 at 12:18, SteamyTea said:

Does this installation do the DHW?

 

I'm guessing not, it being an office rather than a home.

[SteamyTea]

1 minute ago, richi said:

 

I'm guessing not, it being an office rather than a home.

Then the CoP is creditable.

[richi]

On 22/02/2022 at 13:03, Carrerahill said:

Installation seems flawed, uninsulated house with those little radiators? In new build developments with all their insulation we are seeing little 3500BTU rads and that includes a percentage of space for the calculated space heat loss and was based on a delta of 60°. I just can't see how that stacks up. 

 

Yes but a rule of thumb that makes it "seem" flawed might not reflect reality. I gather that they were of the opinion that those rules of thumb weren't helping the industry, in the light of newer, more efficient HPs and better weather comp. So they did some calculations and used their office as a test to verify.

And it's pretty encouraging, right? With some cavity fill and better loft insulation, they'd reduce the energy needed and nudge the SCOP perhaps into the mid-3s. All with no new pipework nor rads.

[Carrerahill]

4 hours ago, richi said:

 

Yes but a rule of thumb that makes it "seem" flawed might not reflect reality. I gather that they were of the opinion that those rules of thumb weren't helping the industry, in the light of newer, more efficient HPs and better weather comp. So they did some calculations and used their office as a test to verify.

And it's pretty encouraging, right? With some cavity fill and better loft insulation, they'd reduce the energy needed and nudge the SCOP perhaps into the mid-3s. All with no new pipework nor rads.

That isn't a rule of thumb, that is calculated room by room heat loss and a sized radiator, on new builds you cannot get by with rule of thumb anymore as you have SAP calcs and CO2 targets and council schemes and standards now. So this installation is systemically flawed. 

[richi]

18 hours ago, Carrerahill said:

That isn't a rule of thumb, that is calculated room by room heat loss and a sized radiator, on new builds you cannot get by with rule of thumb anymore as you have SAP calcs and CO2 targets and council schemes and standards now. So this installation is systemically flawed. 

 

I don't understand your visceral reaction. This isn't a grant job—it's an experiment to demonstrate how far modern ASHPs have come, and what's possible in "challenging" circumstances. Nobody's suggesting home owners shouldn't bother with insulation—but the data are remarkable despite the lack of insulation.

[ReedRichards]

So why is the guy wearing a cap and a hoodie; could it be that he is not feeling terribly warm?  You cannot defy the laws of physics and if the radiators are small then you'll end up with cold house; if the radiators are adequately sized for the 48.5 C flow temperature then you can keep the house sufficiently warm.  It all seems a bit disingenuous. 

[richi]

Okay boomer. If you believe he's lying, that's another thing indeed, but you should probably present some evidence. The data he gives is a constant daytime room temp of 21, set back overnight to 18 (by reducing the flow temp).

Edited February 27, 2022 by richi

[ReedRichards]

If the lesson you are mean to take from the video is that you can install a heat pump without paying attention to the radiators then it's a very bad lesson.   If not, then what is he trying to tell us?

[TonyT]

This  is his office/ workshop where he integrates new technology/tries it out/ possibly does some training before let loose on the public.

 

he had The guys from https://openenergymonitor.org

 to do the monitoring and Trystan did a great video on his own heat pump install many years ago assisted by John Cantor.

[Marvin]

Hi @richi

 

A little confused. At about 57 seconds in to the video an Air to Air pump is mentioned. 

 

I have been assessing our ASHP, and recognise there are many, many factors that effect it's energy use. All the obivious and then how much additional energy is used in the building on everything electrical. Even our WiFi runs at 45 centigrade. Our fridge freezer basically turns 360kWh a year into heat. How many people, doors opening or closing, solar gain, the list goes on and on.

 

I'm not sure, in the video, consideration has been made for all these items.

 

However if your AIM has been achieved (airtightness, insulation, MVHR) its always good to go APE (ASHP, PV,EV). At present one of the best combos. 

 

Another ASHP supporter

 

Marvin

 

 

[Carrerahill]

On 26/02/2022 at 09:31, richi said:

 

I don't understand your visceral reaction. This isn't a grant job—it's an experiment to demonstrate how far modern ASHPs have come, and what's possible in "challenging" circumstances. Nobody's suggesting home owners shouldn't bother with insulation—but the data are remarkable despite the lack of insulation.

I think you have misunderstood me.

 

I said the installation seems flawed, and you replied, "Yes but a rule of thumb that makes it "seem" flawed might not reflect reality. I gather that they were of the opinion that those rules of thumb weren't helping the industry, in the light of newer, more efficient HPs and better weather comp. So they did some calculations and used their office as a test to verify."

 

My reaction was based on you making the comment "rule of thumb", you have assumed that I am basing my response on rule of thumb heating requirement, as a building services consultant I spend my life calculating things, I don't do things by rule of thumb. So for clarity, no rule of thumb, calculated area heating based on calculated heat loss. 

 

My reference to SAP calcs and LA requirements etc. was to point out that rule of thumb heating installations are not done anymore on new builds. Yes, there was a time when a plumber would look at a space, apply some typical figures and work out the heating requirements for a building and that was fine, it was just the done thing, energy was cheap and no one cared about CO2. 

 

Now steering this back round to the point I am making, this installation seems flawed and I cannot see how it stacks up, here is a brand new flat in London, insulated to the hilt, it still needs PV on the roof to offset CO2 to achieve the required DER:

 

 

This is based on maintaining a room temp of 20°. Note the heat input required for this PIR air tight box...

Edited February 28, 2022 by Carrerahill

[Carrerahill]

16 hours ago, ReedRichards said:

If the lesson you are mean to take from the video is that you can install a heat pump without paying attention to the radiators then it's a very bad lesson.   If not, then what is he trying to tell us?

I think the installer is trying to make an arbitrary point that ASHP will work just fine on an older building. It also appears that only about 3-4 rooms are actually being heated with the ASHP. It proves very little. Just that you can heat 4 rooms with 4/5kW.

 

I think he is being a typical installer, "Look it works fine, here I will install 100's of them for all you gullible sorts"

 

 

 

 

[billt]

Yes, he's being economical with the information.

 

If you look at the OEM graph that he shows, he claims that the outside temperature was low and he was still getting a COP of 2.85. When you actually look at the graph, although the temperature did drop for a few days at the end of the period, the average was about 8-9, so not impossible that the COP was reasonable. I seriously doubt that that system could actually heat the space over several days of sub zero temperatures.

 

On the other hand, the Open Energy monitor video is very good and that and the John Cantor web site convinced me that it is possible to run a heat pump system effectively in high energy demand housing. You don't do it by waving your hands in the air, though. You calculate the heat losses, flow rates etc and design the system to suit. IOW you need BIG radiators in a leaky house.

 

John Cantor https://heatpumps.co.uk/ is something of a heat pump expert, and Trystan Lea knows his monitoring.

 

https://www.youtube.com/watch?v=m2-_x0XZUSM

 

Edited February 28, 2022 by billt
Add video

[J1mbo]

I have an Arotherm plus 12kW with radiators set to a 0.65 curve. Over the year the average COP for heating is ~3.45.

 

For interest:

• At 28p per kWh on the cap from April, 8.1p per kWh effective.
• Gas will be 7p on the cap, 90% efficient, so 7.7p per kWh effective.
• Oil currently about 88p per litre and 90% efficient so 8.9p per kWh effective

 

[Luke1]

26 minutes ago, J1mbo said:

I have an Arotherm plus 12kW with radiators set to a 0.65 curve. Over the year the average COP for heating is ~3.45.

 

For interest:

• At 28p per kWh on the cap from April, 8.1p per kWh effective.
• Gas will be 7p on the cap, 90% efficient, so 7.7p per kWh effective.
• Oil currently about 88p per litre and 90% efficient so 8.9p per kWh effective

 

 

Kerosene has only recently spiked to 88ppl because of what is going on in Russian and Ukraine.

 

If you'd bought in early February you'd have paid around 60ppl. 

Lets hope the spike is just temporary, however I fear it may not be!

 

https://www.boilerjuice.com/kerosene-prices/

Edited March 1, 2022 by Luke1

[J1mbo]

It's been at or around 70p for ages before hand. Also prices quoted are usually exc.VAT (at 5%)

Edited March 1, 2022 by J1mbo

[richi]

On 27/02/2022 at 17:17, ReedRichards said:

If the lesson you are mean to take from the video is that you can install a heat pump without paying attention to the radiators then it's a very bad lesson.   If not, then what is he trying to tell us?

It isn't. And I can't see how you could possibly draw that conclusion—unless you didn't read my original post.

[richi]

On 28/02/2022 at 10:33, billt said:

You don't do it by waving your hands in the air, though. You calculate the heat losses, flow rates etc and design the system to suit.

That is exactly what he's saying.

[richi]

On 28/02/2022 at 09:46, Carrerahill said:

 

you have assumed that I am basing my response on rule of thumb heating requirement

No, I haven't. You focused on one phrase in my reply, and your knee jerked.

[billt]

6 hours ago, richi said:

That is exactly what he's saying.

 

In the video he seems to be saying that you can throw a heat pump into any old house with no calculation and it will work as if by magic. I see no evidence that he actually designed a system and his claims for performance are dodgy at best. Claims like that need supporting evidence and I don't see any in the video.