Starting out on my heat pump journey

[Ronski]

I gave up physics at the end of the third year of secondary school when we made our choices for the fourth & fifth year subjects, a rather long time ago now! But even so I knew what you meant by less efficient at colder temperatures, it clearly has to work harder to extract heat from colder air, and if prone to frosting up will need to use even more energy for defrost cycles, thus less efficient.

[Ronski]

As to A level physics retention, which I did indeed pass. I was too busy, shagging, fighting and drinking for it to imprint too deeply. Ah the days!

Try not to appear condescending Mike, it won't fit here.

Best of fortune to ye Ronski, glad to hear you have started your journey.

Sounds like you had more "fun" at school than I did, although I did get in to a fair few fights, which I won, thanks to having three brothers for practice.

The install is progressing, but they do need a little "steering", otherwise I'm going to have a fridge freezer sticking out far more than I would like, and the pipework behind the cabinets is proving tricky.

[Joeboy]

As to A level physics retention, which I did indeed pass. I was too busy, shagging, fighting and drinking for it to imprint too deeply. Ah the days!

Try not to appear condescending Mike, it won't fit here.

Best of fortune to ye Ronski, glad to hear you have started your journey.

Sounds like you had more "fun" at school than I did, although I did get in to a fair few fights, which I won, thanks to having three brothers for practice.

The install is progressing, but they do need a little "steering", otherwise I'm going to have a fridge freezer sticking out far more than I would like, and the pipework behind the cabinets is proving tricky.

It's a bit of a balancing act to get it all.how you want and everyone remains team. A quick cuppa and morning meeting goes well with biscuits.

The ashp system reversal guy I met had 'wan**r' scratched into the back of one of his rads.He found this when removing the system. An extreme example to be sure but it does show to respect the balance!

The best advice I can give is that people don't know what you're thinking, gotta say it. Rarely are new teams all on the same page, it takes time and communication and there won't be enough of the first in a single install so you need to up the second.

P.S there was an awful lot of resin too, hence the blurrage. A time and place for everything i suppose.

[Fueltheburn]

Slight side step here:

I was looking at the various A2A units I could install without the need for F-gas. Paying as much as I did for a hands off approach for my first one really urked me.

This was when I started looking at the different refrigerants. It seems the one which is classed as self-install i.e no certs required for sale or fitting is actually more efficient at lower temperatures.

It would appear R290 is the better choice for a Scottish climate than R32.

[Joeboy]

Slight side step here:

I was looking at the various A2A units I could install without the need for F-gas. Paying as much as I did for a hands off approach for my first one really urked me.

This was when I started looking at the different refrigerants. It seems the one which is classed as self-install i.e no certs required for sale or fitting is actually more efficient at lower temperatures.

It would appear R290 is the better choice for a Scottish climate than R32.

Any links to units?

[Moxi]

FTB - yes R290 would be my preferred refrigerant also for the milder damp North West Coastal area, I think as time progresses older units will not be able to be topped up as their refrigerants fall out of use - as has happened to some refrigerants already - and could cause early retirement of units that are otherwise still ok, add to that the ability to DIY and its environmental credentials and it makes a great first choice.

Moxi

[Stinsy]

Slight side step here:

I was looking at the various A2A units I could install without the need for F-gas. Paying as much as I did for a hands off approach for my first one really urked me.

This was when I started looking at the different refrigerants. It seems the one which is classed as self-install i.e no certs required for sale or fitting is actually more efficient at lower temperatures.

It would appear R290 is the better choice for a Scottish climate than R32.

Correct. R290 is propane which isn't an F-gas (if it was you'd need a license to connect your BBQ!) to the cylinder! Interestingly, I've heard of people on F-gas courses being taught that R290 IS an F-gas. And rather predictably, the industry isn't very happy about it, but then we get into F-gas being a job-creation-scheme or essential-environmental-protection. Seeing as they don't bother with any of this in other countries, where these units are MUCH more common, and in those countries the manufactuers' instructions state that you're to vent the gas to the atmosphere, you can figure that out for yourself.

[MikeNovack]

I was not trying to be condescending But it isn't possible for folks to understand misleading "hype" and manufacturer's claims about ASHP without basic Physics. Or why, IF GSHPs or WSHPs are practical alternatives at your location, they can perform better than ASHPs.

Take "average" COP as advertised for an ASHP. That can be very misleading (disappointing electric consumption over the heating season) if based on "average air temperature" over the heating season. WHY? Because when the outside air temperature is higher, less heat is required for the house. And when the outside air temperature is lower, more heat is required. The heat pump is pumping less heat when the COP is high and more when the COP is low. So the correctly figured "average" has to be weighted by the heat moved at each COP and then that averaged.

Look, this began with my suggestion that IF the log burner was left installed after ASHP put in, an effective use of the log burner would be during cold snaps when the air temperature unusually low (and so the COP of the ASHP unusually low). That is when it most pays to reduce the amount of heat the ASHP is pumping because the COP unfavorable (it doesn't have to pump the heat that the log burner supplied)

[Joeboy]

I was not trying to be condescending But it isn't possible for folks to understand misleading "hype" and manufacturer's claims about ASHP without basic Physics. Or why, IF GSHPs or WSHPs are practical alternatives at your location, they can perform better than ASHPs.

Take "average" COP as advertised for an ASHP. That can be very misleading (disappointing electric consumption over the heating season) if based on "average air temperature" over the heating season. WHY? Because when the outside air temperature is higher, less heat is required for the house. And when the outside air temperature is lower, more heat is required. The heat pump is pumping less heat when the COP is high and more when the COP is low. So the correctly figured "average" has to be weighted by the heat moved at each COP and then that averaged.

Look, this began with my suggestion that IF the log burner was left installed after ASHP put in, an effective use of the log burner would be during cold snaps when the air temperature unusually low (and so the COP of the ASHP unusually low). That is when it most pays to reduce the amount of heat the ASHP is pumping because the COP unfavorable (it doesn't have to pump the heat that the log burner supplied)

Agreed, we have at least one WSHP owner on the forum via a stream and by all accounts it provides a consistent supply of heat with minimal variance. As to WBS and heat pump combo we personally have found it to be a very effective marriage of techs. How popular are ashp's Stateside?

I ask as they are a firm established technology here in Turkey under the guise of inverter aircon systems whereas air source water systems are still seen with some scepticism in large sections of the UK.

Does anyone know of a successful marine HP installation or estuary based?

[Stinsy]

I was not trying to be condescending But it isn't possible for folks to understand misleading "hype" and manufacturer's claims about ASHP without basic Physics. Or why, IF GSHPs or WSHPs are practical alternatives at your location, they can perform better than ASHPs.

Take "average" COP as advertised for an ASHP. That can be very misleading (disappointing electric consumption over the heating season) if based on "average air temperature" over the heating season. WHY? Because when the outside air temperature is higher, less heat is required for the house. And when the outside air temperature is lower, more heat is required. The heat pump is pumping less heat when the COP is high and more when the COP is low. So the correctly figured "average" has to be weighted by the heat moved at each COP and then that averaged.

Look, this began with my suggestion that IF the log burner was left installed after ASHP put in, an effective use of the log burner would be during cold snaps when the air temperature unusually low (and so the COP of the ASHP unusually low). That is when it most pays to reduce the amount of heat the ASHP is pumping because the COP unfavorable (it doesn't have to pump the heat that the log burner supplied)

People I know with a HP report real world CoPs way higher than expected. I've seen plenty of people take the kWh figure of their previous gas consumption and apply a CoP of 3 or 4 to estimate how much energy their HP will use and then find it uses WAY less. Mainly because their gas boiler was much less efficient in the real world than advertised but also because thier HP works better than advertised.

I have heard of a few underperforming systems, but this isn't something intrinsic to HPs, it is cause by things such as: undersized pipework, undersized emitters (rads), excessive zoning, etc.

I fear that you are regurgitating FF industry misinformation!