ASHP, how to decide - I just don't get it!

[Dave Jones]

9 minutes ago, JamesPa said:

....because people are still labouring under the misapprehension that tackling climate change wont involve any sacrifices, and weak-willed governments are indulging (arguably encouraging) that fantasy. 

 

Had we started properly 20-30 years ago, it might have been possible to adapt without sacrifice.  Now it isn't.  We will both see devastating effect of climate change (most likely manifested as mass migration and armed conflict) and have to adapt our behaviours to stop it getting even more catastrophic.

 

maybe. nothing guaranteed.

 

until china stops with its coal powered fire stations we should be pausing everything anyway as its pointless.

[JamesPa]

15 minutes ago, Dave Jones said:

 

maybe. nothing guaranteed.

 

 

I think the science says that it is guaranteed, had has done for decades.  Deny it if you will but the science doesn't care what you or I think.

 

16 minutes ago, Dave Jones said:

until china stops with its coal powered fire stations we should be pausing everything anyway as its pointless.

 

The problem with this argument is that it means everyone waits for everyone else and nothing gets done.

 

My personal bet is that China will eventually sort their emissions better than the west, because they can due to the way their political system works.  Either that or their low lying costal communities will get hammered. 

 

Of course the Chinese also have form when it comes to unnecessarily sacrificing the lives of their own people.

 

 

[saveasteading]

55 minutes ago, Jimbo37 said:

there is precious little vocal advocation for the consume-less solution, 

It has been the case ever since "sustainable design" became fashionable and attracted grants, (about 20 years ago?).

The quangos set up to support "green construction" only knew about wind turbines,  solar panels and reducing landfill.

 

 My company entered sustainabilty competitions. Our premise was for no bling, only proven technologies, on-site drainage, and, most importantly, integrated and efficient design ("use less stuff").

Judging panels were split between full support and utterly not understanding. One judge said we were cutting corners and not generating power on site. 

 

This improved a bit in a few years, and the turbines were seen to be useless and so on.

But design is still usually linear. Client - architect - engineer - qs - builders. Few question the process.

That was great for my business and any similar who had everyone in the same room, and we would make radical revisions at any stage.

 

The overuse of materials could be 30% which is an awful lot of carbon.

 

Self builders have the opportunity and desire to build efficiently. 

 

Efficient design , qusetion everything, insulation, airtightness .  Be prepared to refuse alternative energy. Site control of waste (including overuse)  on site.

 

[saveasteading]

Example

Few question the process.

 

We were a steel subby on a big contractors site. They were deliberately overdigging foundation pits, shuttering the size required and pouring concrete, then removing the shutter and backfilling with gravel. 

I mentioned to the project manager that this was wasting materials, time and money.

His response was that this was on the drawing and they were getting paid for it.  I'd say 30m3 of muck away, 30m3 of gravel, and all the work, all pointlessly. 

To me that is unfirgiveable waste, but most sytems only count skips as waste.

 

Overdigging trenches is very common. The client is usually paying for the extra concrete.

 

Self builders don't often have lots of timber offcuts at the end of the job.

Big contractors do, but will have a certificate that shows it didn't go to landfill.

 

"Use less stuff."

[saveasteading]

35 minutes ago, Dave Jones said:

until china stops with its coal powered fire stations we should be pausing everything anyway as its pointless.

I don't steal or murder. Some other people do.

I will continue to not steal and not murder, even if they won't. 

 

I try to reduce materials, energy use and limit pollution. Some other people don't.

I will continue.

[JamesPa]

1 hour ago, saveasteading said:

I don't steal or murder. Some other people do.

I will continue to not steal and not murder, even if they won't. 

 

I try to reduce materials, energy use and limit pollution. Some other people don't.

I will continue.

Fair position I'd say, similar here.

 

Of course we have to be a bit careful blaming China, a proportion of their consumption is really ours as its burned to feed our relentless desire for cheap stuff.  We outsourced pollution when we outsourced manufacturing, but that doesn't absolve us of responsibility.

[SteamyTea]

4 hours ago, JamesPa said:

Had we started properly 20-30 years ago, it might have been possible to adapt without sacrifice

The electrical generation industry started, in earnest, planning and building windfarms 30 years ago.

It takes the first decade to get though planning, then it was relatively small scale stuff employed, then the moratorium happened that forced the wind industry to  develope techniques to cost effectively install at sea.

Last year wind power generated more electricity than gas (I think).

Now wind is the cheapest form of electrical generation, whether the fossil fuel industry likes it or not.

Increasing solar generation is going to be the next target for growth, not nuclear, tidal or biomass, the economics don't stack up for them.

 

Just looked up when Delabole Windfarm was built.

1991. It was proposed in 1989. So 2 years to get though planning and constructed.

That was 32 years ago.

What the (expletive deleted) is wrong with us in this country, we have really lost the plot on planning and infrastructure.

Edited May 29, 2023 by SteamyTea

[saveasteading]

This may be the craziest bit of sustainability bling ever.

I heard it could power 2 kettles if the wind was the right direction and strength.

The extra cost must have been many millions.

Perhaps sponsored by the oil industry to ridicule wind power.

 

[SteamyTea]

1 minute ago, saveasteading said:

This may be the craziest bit of sustainability bling ever

Not that crazy. No worse than a green roof in reality.

[JamesPa]

Didn't you mean

 

1 hour ago, SteamyTea said:

What the (expletive deleted) is wrong with us in this country, we have really lost the plot.

 

On the positive side, having now test driven several electric cars in preparation for when our ICE car finally bites the dust, they are an absolute no brainer once range anxiety is sorted and price parity reached, neither of which is very far off, albeit that it might wipe out the european car industry in the process.  They are just better cars. 

 

Imagine if electric cars had come first and someone offered you a car powered by a load of small explosions with twice as many parts, poorer acceleration requiring you to visit a special place to fill up with an explosive liquid that pours fumes out the back.  Its not going to sell!

 

ASHPs however are a different matter.  The technology is there, but we seem to lack the skills or tools to design the system well on a reliable basis, and then we supplement it by cloth eared LPAs like mine that demand unachievable and irrelevant noise specs.  Hopefully the likes of Octopus will sort the former out - the grant harvesters and the Government certainly wont.  I'm surprised that the ASHP manufacturing industry is not more active in the design/install market.

[SteamyTea]

8 minutes ago, JamesPa said:

Imagine if electric cars had come first

They nearly did.

https://energysavingtrust.org.uk/a-brief-history-of-the-electric-car/

 

Probably failed because no one wanted to by a car from a yamyam called Parker. Should have stuck to pens and driving Lady Penelope about, 'My Lady'.

[Shaun McD]

I feel your pain @Jimbo37, based in Donegal and finding it very difficult to get anyone to "design"! I think we have had maybe 1 reputable installer so far ask for heat loss, and i asked a couple of others if they would not need to know heat loss, one answer was that he uses 40W/m2 for new builds. Thats at 25 deg temp difference, and maybe is not terrible, but my calcs for 25 deg is 15.9W/m2, so would be some what overkill to install a heat pump to hit 40! 

One of the main challenges I have found, as others have also stated, is getting a machine as someone not in the trade. A couple of plumbing supply stores will sell me a machine, told me they wont give me the same price as the plumber (odd) but that it will be sold as seen, zero warranty. I have had a little more luck with commercial refrigeration companies, e.g. a company based in Donegal told me that they will sell me a Daikin unit, and if I have their engineers commission and do an annual service then they can provide the full 7 year warranty. 

There is options out there, just a PIA to find! I am trying to work with some local plumbers and take an active role in design to see can I find a happy medium, but may end up a DIY job yet

[TonyT]

I think you could find someone in the UK to design the system and then just hire in the trades.

 

 

[Shaun McD]

1 minute ago, TonyT said:

I think you could find someone in the UK to design the system and then just hire in the trades.

 

 

 

Plumbers have very sensitive ego's, they seem to struggle to do what the customer asks, let alone take some other mans seconds...

[TonyT]

I would be happy to work to a design knowing I’m not responsible for that part, all I have to worry about is my workmanship.

 

find new trades that think differently

[Shaun McD]

1 hour ago, Shaun McD said:

 

Plumbers have very sensitive ego's, they seem to struggle to do what the customer asks, let alone take some other mans seconds...

 

Apologies for the rude statement, i would like to edit this to state that this is my experience with SOME plumbers, and it is clear based on this forum alone that there is a huge difference in how some wish to operate! I have no doubt there will be plenty of plumbers who would be happy to work of a design and also provide input free of charge, like several on here who have given their time and knowledge for no financial gain, but they are just tough to find in my area! I will endeavor to keep hunting!!

[HughF]

Design it yourself, but the unit from Chris at CoolEnergy. Great product, great support.

 

Find a local plumber, they’re easy as piss to install.

[SteamyTea]

2 minutes ago, HughF said:

Find a local plumber, they’re easy as piss to install.

Almost.

The wet side is basic.

The controllers can cause problems, especially if the end user does not have the correct access codes.

[HughF]

35 minutes ago, SteamyTea said:

Almost.

The wet side is basic.

The controllers can cause problems, especially if the end user does not have the correct access codes.

Buy the right unit and the controllers are a piece of piss too…. The carel platform on the CE units really is fantastic in this regard.

[SteamyTea]

1 minute ago, HughF said:

Buy the right unit and the controllers are a piece of piss too…. The carel platform on the CE units really is fantastic in this regard.

That is the type of thing that a new user needs to know.

Do you have a link to more details?

[JohnMo]

1 hour ago, SteamyTea said:

Almost.

The wet side is basic.

The controllers can cause problems, especially if the end user does not have the correct access codes.

You do need access to the installer password, I just went direct to the manufacturer, they were good and gave them to me, I just said I was installing and needed the code.

 

Had to find the installer manual online, to get all the codes for different parameters, in total 18 different parameters needed some input. Most were basic, like setting up DHW from a switched thermostat instead of PT100 probe, heating and cooling curves, enabling summer/winter switch. There were only two real running parameters to change.

 

They were the fine tuning of the behaviour of when the heating/cooling cycles stops and starts up again. Out heat pump ran for 20 minutes, then stopped and basically say idle for about 4 hours.

 

So for anyone interested this is what happens.

 

You have a demand flow temperature let's say 26 degs.

 

Heat pump will slowly bring the flow temperature up to 26 and try to hold it there, once the demand temp has been exceeded by "X" degs the heat cycle will stop. My original setting was 0.1 degs, so at 26.1 degs the heating cycle stops - I bumped that up to 0.5 to give a longer run time.

 

Once the heat cycle has stopped the heat pump will resume heating when the return temp has dropped to flow temp, less target delta T, less a value "X", this being set at 2.5 from the factory. So return temp required to drop to 26-4-2.5=19.5. my lowest return temp was alway higher than this so I reduced the "X" parameter and ended up at 1.6 instead of 2.5.

 

As we have seen many times the installer doesn't put in much work in to the controller side, does the most basic so he can walk away. In my case he would not changed the the settings mentioned above, he would have set the flow temp to 35 instead of 26 and left cooling switched off.

 

Just had a look at my electric input over the last 23 days and my average is 6kWh per day. This includes 9 hrs slab cooling (4 to 6kW removal rate) (190+m2) and DHW heating to 2 people each day, electric mostly from PV.

[HughF]

28 minutes ago, SteamyTea said:

That is the type of thing that a new user needs to know.

Do you have a link to more details?

 

There’s the manual. It has a single call-for-heat dry contact that can go to a programmer, hi-limit stat or just a simple on/of switch. The main controller does everything else

[Brendan]

On 26/05/2023 at 16:48, JamesPa said:

They do need a good problem solving brain,  a good toolkit of options, some common sense, and some sound techniques. It seems that they aren't currently given this by MCS.

...

There is ample evidence that the fabric assumptions simply aren't good enough on their own.  But it's drummed into them by MCS that the spreadsheet does the job. 

 

 

 

I have just ended a 7 month dispute with my builder and their plumber about the design of my ASHP system.  Their plumber is not MCS certified and has no objective qualifications to prove he understands how to design an ASHP system.  I wanted an MCS-certified intallation, partly to get the grant and partly to have some peace of mind that the system is properly designed.

 

I have thoroughly read all of the MCS documents several times.  If you take the time to understand what it says, it is clear that a degree of common-sense is required. This is where some MCS-certified designers fail as they just read the basic instructions and use the spreadsheet incorrectly.

 

My house was built in 1961.  The MCS-certified designers my builder approached (MCS umbrella schemes - they design and certify a system for a non-certified plumber to install) all decided that for ventilation rates and room temperatures on the MCS spreadsheet, the house therefore needed to be treated as a pre-2000 construction.  In reality my house is a heavily renovated property, designed by a specialist architect to meet Enerphit standards.  Therefore it makes a lot of sense to treat it as a new (post-2006) building. This makes a huge difference to the heat loss calculations.  This is in the spirit of the MCS standards, which also point the designer to the CIBSE heating system design guide, which itself says that for modern, well-insulated buildings, specialist advice would be advised (rather than making uninformed assumptions).

 

My architect's plans included detailed u-values for all sections of the building and I know the manufacturer's u-values for the doors/windows, so there is little guesswork required by the designer.  The architect's heat loss for my house came out at around 3.9kW (they use PHPP), I got 4kW out of the MCS spreadsheet calculator, two MCS certified companies I approached got 4kW. The two MCS umbrella scheme providers and my builder's plumber all calculated my house's total heat loss at around 8kW.

 

It all comes down to how carefully you read the instructions, how well you use them and how clearly you understand what you are doing.

[JohnMo]

If you need 4kW for heat that leaves no room for DHW heating if you went for a 4kW ASHP.  So you will a  5-6kW ASHP, just need to check it delivers the required temp and kW at your lowest outside air temp.

 

Our house need 3.5kW for heating and I installed a 6kW, mainly because it was super cheap and was near enough.

 

If you have builder, electrician and plumber on hand why are you wasting money on MCS rip off?

[markocosic]

On 29/05/2023 at 17:27, SteamyTea said:

No worse than a green roof in reality.

 

Perhaps worse?

 

Zero benefits whatsoever since they were shut down due to vibrations/sound in the penthouses.