Posted by: @editor

@hughf, have you got a Homely?

It seems very helpful if you’ve had a decent install. I’m not sure it would improve our system greatly due to the reducing pipe bore in the north end of the house. I’ve been conducting experiments for a fortnight now and it’s frustrating when you retrofit a system not knowing what’s behind the walls.

I don’t (yet) Mars, although it’s on my list for when I install my system next year. Although I sound like a salesmen when I go on about it, as an electronics and software engineer, the way it deals with the problem of weather compensation curve optimisation and setup is just perfect. Controlling the heatpump flow temperature in realtime over rs485, perfection….

No need for the installer to ever visit the property to make adjustments, and the end user gets an easy to use UX. All the clever stuff is hidden away, as it should be.

@hughf, didn’t sound salesy at all. Was just curious to see how it performs. I don’t know anyone with a Homely bar Graham Hendra who really rates it.

Posted by: @editor

@derek-m, you’re spot on. There’s no silver bullet. Every system is so unique and requires a different approach. So there’ll be some repetition for sure, but most of the advice will have to be provided specifically for each set up and each heat pump.

I don’t completely agree with this Mars, and I’ll suggest why; Heatpumps give best COP when the flow temp is low, we know that. Low flow temp comes with weather compensation, but this requires experimentation and installer call back to get right. 

Then there is the control strategy that’s pushed by building regulations - ‘you must have two thermostats’

We often see people saying that their system works but the rads are too hot or too cold etc… or they are turning the system off completely because they have a room thermostat that has been wired up as an on/off control.

These problems are endemic to all the bad heatpump installs - fix those things and most of these bad installs will magically become better. Not ‘best’, but better…

So I’d suggest that the silver bullet is in fact quite simple - Weather compensation with a self optimising curve based on a room sensor and user input (‘I’m too hot’, ‘I’m to cold’ sort of answers). This would work across the board.

@hughf, I don’t disagree with you and I’m actually wrapping up a post on this that I’ve been working on for a fortnight. Weather compensation is great when enabled in a well designed system. Our installers never enabled it and told us not to use it. Awful advice, I know, and our installation was OK - definitely not amazing.

Problem with weather compensation is trial and error. Many homeowners are too scared to experiment and there have been countless conversations where installers lock users out of the control panel so you can’t change anything.

Our settings were all locked away behind a password. I got access because I insisted, but I don’t know how many people would.

Hopefully the post will go live tomorrow.

Posted by: @hughf

Posted by: @editor

@derek-m, you’re spot on. There’s no silver bullet. Every system is so unique and requires a different approach. So there’ll be some repetition for sure, but most of the advice will have to be provided specifically for each set up and each heat pump.

I don’t completely agree with this Mars, and I’ll suggest why; Heatpumps give best COP when the flow temp is low, we know that. Low flow temp comes with weather compensation, but this requires experimentation and installer call back to get right. 

Then there is the control strategy that’s pushed by building regulations - ‘you must have two thermostats’

We often see people saying that their system works but the rads are too hot or too cold etc… or they are turning the system off completely because they have a room thermostat that has been wired up as an on/off control.

These problems are endemic to all the bad heatpump installs - fix those things and most of these bad installs will magically become better. Not ‘best’, but better…

So I’d suggest that the silver bullet is in fact quite simple - Weather compensation with a self optimising curve based on a room sensor and user input (‘I’m too hot’, ‘I’m to cold’ sort of answers). This would work across the board.

 

Hi Hugh,

The control system you describe is already present on a number of heat pump system that are available now. The Mitsubishi Ecodan has both weather compensation and auto adaptation. It should therefore be possible to roughly set the weather compensation curve and then let the auto adaptation make the necessary fine tuning.

As you have correctly pointed out, many installers fit on - off thermostats, so that they don't have to attempt setting up the weather compensation curve, which they probably don't fully understand. Many other times they would not be able to utilise auto adaptation, since many of the installers seem to insists on locating the controller, containing the temperature sensor, in the loft, airing cupboard, or even in the garage. Under those conditions I don't think that Homely would prove any better, since it would not be provided with the correct information on which to operate.

How much does Homely cost and is there a monthly fee involved?

I’m also aware that most installers seem to leave the most powerful controller available, that from the heat pump manufacturer, stuck in the loft or in an unventilated garage - totally useless as you say.

The homely indoor temperature sensor uses zigbee to communicate with the main control unit, and can be placed anywhere in the home.

A subscription of £25/annum (I think) is required to enable the smart tariff integration, whereby homely knows the electricity unit pricing for the next 24hrs. I have no idea how much it costs.

I’m not totally sold on it though, the lack of a nice, back-box mountable, in-home-display is a downside, relying completely on an app. Not ideal for the non-tech savvy user. I think it should have a wall mounted ‘temperature control’ dial, or at least support reading the user-requested temperature from an open therm compatible wall stat such as nest or tado.

@hughf

I fully agree that many of the manufacturers manuals are poorly written, with obscure descriptions used to identify some of the functions. I have had to read through some several times, before the penny finally dropped, and reading through 600+ page manufacturers manuals for industrial control systems was what I was often paid to do.

The further problem is the apparent lack of adequate training, from which many installers appear to suffer, whether that is due to lack of opportunity or just lack of interest I don't know.

What I feel is obviously required is a set of crib sheets for each system, detailing where the various components need to be installed, what initial settings need to be made, and how to navigate through the controller to find and make such settings.

With a little practice you may then find that installers, leave their customers, happy in the knowledge that the system has been correctly installed, configured and optimised.

A further requirement would be to shoot a designer each day, until they get it right. 😋 

if you have a midea samsung or hitachi heat pumps i have done videos how to adjust your weather comp.

YOUTUBE.COM "https://www.youtube.com/channel/UCH3B9qBaEpcpawjMEMKVLOQ"

Before you continue to YouTube

hope they help

@grahamh

I think the point that was first being made was that the customers should not have to be making numerous adjustments. The designers and installers should be providing systems that work correctly and efficiently from day one.

Posted by: @derek-m

Posted by: @benseb

How about a sticky post to help people out?

 

take them through the steps

 

Might save a lot of repetition!

It is not quite that simple, since the required procedure can be very different from manufacturer to manufacturer.

There is also the problems associated with different home types and layouts to quite differing system designs. What can work well in one situation may not be particularly good in another.

We should just direct them all to the site below, which appeared in an ad link in this one.  In fact I'm thinking of ditching the ASHP and getting a few of these little fellows instead.  They'll be much simpler to work and I'll save £4,000 per year!

@kev-m

Great news Kev, but being a Yorkshireman I'm waiting for the BOGOFF deal. 😎 

Posted by: @derek-m

@hughf

I fully agree that many of the manufacturers manuals are poorly written, with obscure descriptions used to identify some of the functions. I have had to read through some several times, before the penny finally dropped, and reading through 600+ page manufacturers manuals for industrial control systems was what I was often paid to do.

The further problem is the apparent lack of adequate training, from which many installers appear to suffer, whether that is due to lack of opportunity or just lack of interest I don't know.

What I feel is obviously required is a set of crib sheets for each system, detailing where the various components need to be installed, what initial settings need to be made, and how to navigate through the controller to find and make such settings.

With a little practice you may then find that installers, leave their customers, happy in the knowledge that the system has been correctly installed, configured and optimised.

A further requirement would be to shoot a designer each day, until they get it right. 😋 

I’m firmly of the belief that it’s all the installers fault for not educating themselves. I’m going to stand by that until I get convinced otherwise…

I don’t even work in the plumbing and heating industry and I know more about how this stuff works than half the ‘plumbers’ I end up arguing with in the YouTube comments section.