Daikin heat source pump

[shergar]

Kings Meadow was a new housing development in Cirencester some 15 years ago.
All the private houses were on gas. Social housing was on air source heat pumps, leaving the tenants to pick up the bills, whilst the Housing Association pocketed the government grants. Underfloor heating might have made it slightly more viable but the opportunity to install it during the construction stage was omitted, demonstrating a cynical approach to energy conservation.
Under floor heating brings two benefits. First flow temperature no higher than 55 degrees. Second, if a concrete oversite and screed, the floor becomes a heat store,otherwise not present in new builds. Dot & dab plasterboard together with thermal blockwork reduces capacity of walls to store heat.
Claims that Air Source Heat Pumps work for domestic property in the UK should be regarded in the same manner as a claim that it is possible to boil an egg with a candle.
With the added proviso, if the water is colder, candle is reduced in size. In the manner that COP (Coefficient of Performance) rapidly reduces at the times when heating is most necessary.
Edit:-
Not just theory, I've worked on many systems, correcting poor installations. Even when correct performance leaves much to be desired.
Photo shows low loss header for two outside units and three circulation pumps.

 

[CJD]

In an old traditionally built house in the uk- unless it has a massive amount of additional insulation as well as bigger rads proper heat loss calcs etc they ain’t going to work correctly.
You will haemorrhage money and your electric bills will be through the roof.
Purpose built new housing is a different matter- nice insulation, underfloor heating etc and they work very well.
Personally I wouldn’t touch one in an older property- I’m sure others will disagree!

 

[Nias]

If you are looking into heat pumps now or in the future here is live data from installed heat pumps https://heatpumpmonitor.org/ the SPF value is the average efficiency for the whole year so it includes winter- higher is better. I think if the value is 2 it will cost the same as gas to run (1) if you get the 1/2 price electric deals.

It also shows the installer so you can get an idea of the good installers in your area. I think Heat Geeks guarentee 2.8 COP in any house.

 

[David Marchant]

Air source heat pumps are as good as useless in the U K. If you have an absolute top quality installation it might just do the trick, but the systems are very complex (compared to a simple gas boiler) very few installers can set them up properly and even fewer can do servicing and repairs.
Another myth is the one about saving you money.

 

[Nias]

If you look at the live data over the year it seems to say they work well.
Even setting the chart to last 30 days when we had the freezing weather all bar the bottom 5 look good. These are independant individual sets of data when the customer has added extra hardware to monitor the system around £500 I think. Anyone can add it. I notice there are a couple from Northern Europe as well.

You could say having live data to monitor your system means you can tweak your system to get max benifit. Could be why these online systems seem to perform well?

In Northern Europe where the average winter temperature is much colder than the UK heatpump uptake is massive.

 

[David Marchant]

If you look at the live data over the year it seems to say they work well.
Even setting the chart to last 30 days when we had the freezing weather all bar the bottom 5 look good. These are independant individual sets of data when the customer has added extra hardware to monitor the system around £500 I think. Anyone can add it. I notice there are a couple from Northern Europe as well.

You could say having live data to monitor your system means you can tweak your system to get max benifit. Could be why these online systems seem to perform well?

In Northern Europe where the average winter temperature is much colder than the UK heatpump uptake is massive.

That's another 500 quid he will have to recover from the expected savings. They work better in northern Europe as the properties are much better insulated and the low winter temperatures are constant. You could heat one of their homes with a couple of candles.

 

[David Marchant]

I've been researching this for a couple of months, I don't know how much information I've soaked up, I've heard all the sides, and there are strong feelings on both sides of the fence over heat pumps.

I obviously don't have all the details of your system @stefan, but without sounding rude, it's clear the installers did not explain to you how a heat pump works, or how to use one, because they are not the same as a gas boiler, and people struggle with the concept of keeping them set to low permanently rather than using it like a boiler where it turns on and off. They also have to be set up right, with weather compensation and correctly balanced for each room, and although I don't know if this has been done in your house, neither does it sound like you do, but you need to ask and get it rectified if your ever going to get it running properly?

Systems like the one you have said has been fitted tend to be a once size fits all approach fitted by guys who just follow a plan and don't give two hoots about how it works or what the repercussions are when they cut corners - "not my problem mate" They don't care how it works and don't show you how to work it. It's like learning to drive a car, the first time you get behind the wheel your driving is crap, but there is nothing wrong with the car, you just haven't learned how to use it yet

Basically, a heat pump is designed to be set to temperature and then left running permanently. It will take hours to heat up as it runs at far lower temperatures than a gas boiler, that's deliberate, low and slow is far more efficient than hot and quick running on an on/off cycle. Your gas boiler has your radiators hot/cold depending when it's running, so they go from about 70 degrees to room temperature on/off constantly - imagine driving along the motorway like that - 70mph then 40mph, then 70mph, then 40mph - what would your fuel consumption be like? Better to drive at a steady 60mph, get great mpg, and get there in the same time

As for finances, a gas boiler is about 85/90% efficient depending on age (or less if old), so at 6p per unit, it actually costs about 7p per kwh in practice.

A well installed and set up heat pump is around 350/400%+ efficient across the year, so for every 1kw of electricity you put into it, you get around 3.5kw of heating power out of it. (it's a physics thing to do with compressed gasses, like a fridge running backwards) If electricity is 24p/unit, then divide that by the 350% efficiency and it makes the equivalent cost 6.8p per kwh of heat - basically on par or slightly cheaper than gas.

The big difference here, is if you now start using time of use tariffs designed for heat pumps like Octopus cosy, then you will pay around 15p per kwh to run your heat pump, making it far cheaper to run than gas. Go one step further and get a solar array and large battery, (admittedly this is a big cost for most) and your now running it permanently at around 7p/kwh - and at 350% efficiency that means your spending 2p/kwh on heating, or a third of the price of gas Over time it will pay for the investment, but it does take years, although yours was put in for free, you just need to get to grips with it

So I'm out on this, people will believe what they will believe, but the problem with heat pumps is not heat pumps, it's poor quality installs and poor explanation of how they are set up and how to use them.

I know it's homework, but if you want to learn about heat pumps, go here and pick a couple of videos that fit it with what you want to know, it may give you the questions you need to speak to your housing association about, whether or not they now the answers is something different entirely

Heat Geek

Heat Geek is the UK's leading resource for smarter, more efficient home heating. We connect you with the best-trained heating engineers in the country and guarantee high-quality air source heat pump installations - designed to lower your bills and reduce your carbon footprint. Whether you're a...

www.youtube.com

In the very best scenario you have spent all that money to listen to the noisy fan in the heat pump and it MIGHT save a tiny amount on your bill! All that mess and expense for what?

 

[Nias]

I think for once there is agreement across all political parties that heat pumps work and the colder counties think so too. £7500 is a lot of money for the Gov to spend on something that would make your house cold.

At the moment it is still not viable for larger houses as we have seen from quotes but the nearer you get to £7500 total cost it must be good.

For me I still have a gas boiler but I have 2 air to air heat pumps(lounge and master bedroon) as well which means I get the 51% off electric deals.
I have a fairly large 1960s house and have been quoted £7500 inc the discount for a heat pump. A normal boiler would cost around £4000 so I am paying £3500 extra for a heat pump.

I then get to shut off my gas, stop paying the standing charge and cut my CO2. Looking at the live data I will get to save money each month as well.

 

[Warthack]

All I can say is our heat pump works fine, keeps the house at a steady 22C, saves us money, and will pay for itself in the savings it's made (based on the cost of running an lpg combi boiler alternative) within the next 3 years. We've had it running just under 4 years now. It gets serviced every year by the installer and we've had no problems.

We replaced the old boiler system prior to moving into the house 4 years ago after renovating my mum and dad's house, a large ish 1840 detached cottage, which we moved into as they needed full time care.

All radiators were oversized after a heat survey, some piping was replaced and we added some internal insulation to the solid walls, and the loft was further insulated. It was a bit of disruption, but nothing that could not be tackled a room at a time.

It works for us.

 

[pjgtech]

Ex plumber and ex surveyor here and personally I would not have one at all!
They are (in the UK) mostly overhyped rubbish, generally poorly designed and poorly installed and not suitable for (most) UK properties.
Local Housing authorities will just be getting the cheapest ones they can and will be throwing them in at a vast rate so they can tick various boxes, please the Govt and probably get many grants to boot!
They work in other Countries, eg: Scandinavia, but they have much higher building standards, much better insulated homes, and are generally only part of the heating/hot water system, with other things supplementing the system, eg@ Solar, Vacuum tubes, good insulation, open fires, triple glazing, etc, etc. Which we generally, erm, don't!

 

[pjgtech]

I think for once there is agreement across all political parties that heat pumps work a

Yeah, whenever politicians agree on something, thats always something to get worried about IMHO!

 

[colinb]

So our housing association has installed a heat source pump, well if your a private house owner don’t ever ever buy a heat source pump they are shit beyond belief utterly a waste of money it took four hours to get to 20 degrees keep your gas boilers at all costs,new radiators throughout the house also fitted this week a whole new heating system which is utter shit I can’t believe people are that ****ing stupid to install these things so ****ing angry right now , even to the point phoning housing association and telling them come take the poxy shit thing away as it’s shit. Rant over

Ah, yes, but the point of a heat pump is that it works gently for many hours. It might give 6-8kW on a good day for a consumption of only 2-3kW, as opposed to a nasty horrible gas boiler giving maybe 25kW. So starting from cold will take longer. Wait until your bills arrive. The problem is that a unit of electricity is 4x more than a unit of gas and the heat pump is not 4x better. If you are lucky the bills might just only go up by 25% or so. But by the time Mad Ed adds another £500 to all our bills....

 

[colinb]

Sorry missed the bit where you said they fitted new rads. Sounds like they have done the heat loss calcs etc. I presume your house was without heating for a few days? If so it will take a few days to warm the fabric of the house back up. Hopefully once the house has warmed up the heat pump will be able to top the heat up when needed.

I am interested in this post as my boiler is around 12 years old now and I know if it goes faulty they prob won't repair it so I'll have to decide on a heat pump or gas boiler.

My boiler is 24 years old and I repair it. When it breaks. Which is never in the last 10 years. The last time it broke was after the gas man called and serviced it. Then put it back together not in accordance with the manual. It broke on Christmas day... Experts? Bah, humbug.

 

[pjgtech]

Basically, a heat pump is designed to be set to temperature and then left running permanently. It will take hours to heat up as it runs at far lower temperatures than a gas boiler, that's deliberate, low and slow is far more efficient than hot and quick running on an on/off cycle. Your gas boiler has your radiators hot/cold depending when it's running, so they go from about 70 degrees to room temperature on/off constantly - imagine driving along the motorway like that - 70mph then 40mph, then 70mph, then 40mph - what would your fuel consumption be like? Better to drive at a steady 60mph, get great mpg, and get there in the same time

As for finances, a gas boiler is about 85/90% efficient depending on age (or less if old), so at 6p per unit, it actually costs about 7p per kwh in practice.
A well installed and set up heat pump is around 350/400%+ efficient across the year, so for every 1kw of electricity you put into it, you get around 3.5kw of heating power out of it. (it's a physics thing to do with compressed gasses, like a fridge running backwards) If electricity is 24p/unit, then divide that by the 350% efficiency and it makes the equivalent cost 6.8p per kwh of heat - basically on par or slightly cheaper than gas.

Heat Geek

Heat Geek is the UK's leading resource for smarter, more efficient home heating. We connect you with the best-trained heating engineers in the country and guarantee high-quality air source heat pump installations - designed to lower your bills and reduce your carbon footprint. Whether you're a...

www.youtube.com

Yeah, I've never been convinced by those efficiency figures, which are often quoted....as they seem to be mostly obtained by the people supplying them, or recommending them, or installing them, not independent by any means, so I would like to see some actual scientific studies done personally to confirm or deny those stats?
I think there may have been studies done in Scandi Countries, (and stats are used from there) but the situation there is very different to the UK, better housing stock, better insulation, supplementary systems in use, not just ground/air heat source, solar, etc, more mature market with years of experience in this sector, etc, etc.

 

[colinb]

When I switch my current heating off, the entire house haemorrhages heat so quickly that it’s stone cold within one or two hours. We have had to have a high pressure system boiler because a combi boiler just won’t work in a house of our size. We do have insulation and double glazing though, it’s shit. Luke warm radiators would not stand a chance. Not a snowball in hell!

We wanted a heat pump system as when both zones are on and set to a reasonable 20C, it costs over £30 a day to run. We had a bloke visit, he told me a heat pump system would cost £20k before fitting additional insulation and new radiators which would cost an additional £10 to £15k….. I told him I’d put a jumper on..

The only place heat pumps should be fitted is in new builds. To retrofit does not work… utter waste of money…. Another stupid idea put forward by government blaming us for global warming.

I think you need an Eskimo suit each.

 

[pjgtech]

Just to add, you CAN get an air/ground heat source pump/system to work in the UK, but, and its a BIG but.....
It will not be cheap, it will require either a new very well insulated house or an older house to be fully re-insulated, it will take a full and proper survey, heat loss calcs, etc, it will take good equipment, not the cheap end) and good installers who know what they are doing.
So, yes, it can be done.
But..... sadly in the UK that criteria is rarely met.
But generally not in most older UK properties for anything like £7.5k, try doubling that and maybe even tripling it and then you might be getting somewhere.

 

[Neptune]

And so to summarise
It will be fine for some people, not for others, do your homework and decide for yourself. Know how to use one before you get one.

 

[chinook]

All this tech stuff is interesting. I disgree with the idea that grants of 7.5k are government money, the government has no money except that which it takes off all of us! So, we are all paying for some of the installations for everyone else, and then we will be told to pay whatever it costs for our own heat pumps. Some will say - so what. Then I look up and down my street and think this is one street, in many many thousands of similar streets and if they all had to have heat pumps and if in the very cold weather we get all these fan units are drawing 2, 3, 4? kW every hour upon hour, where is all that electricity coming from? We import from France, and Norway soon, there are turbines everywhere and near us here thousands of acres of prime food growing land is being covered in solar panels. Will it be enough, I dont know, but you can be sure there are billions of pounds to be made so crack on, eh!

 

[Nias]

You can test your own house out if you have a gas boiler with a digital boiler thermostat.
When I started looking into heat pumps a few years back I turned my boiler stat down to 53. Left the hot water tank set to high 50s to kill Legionairs bugs.

I have a 1960s largish house with huge 1960s windows in every room. All rooms have at least 2 external walls, some have a 1960s flat roof with 50mm insulation.

I have 300mm loft insulation in places 200mm in others. I did my own heat loss survey (you can download a spreadsheet to make it easy) and a few of my rooms are OK with the radiators I already have the others are a bit low and would need changing out.



This is the 2nd winter now and yes the house does take longer to heat and I can touch the rads without getting burnt but it certainly works.

With my gas boiler the rads are warm in 30mins whereas a heat pump would need to be on longer to keep the heat topped up.
When it was down to -3 outside a few weeks back I set the thermostat to 17 overnight so the house would get some early morning warmth.

From what I have seen most plumbers when they fit a boiler whack the stat upto 70 which is very inefficient for a combi (if you see loads of steam comming out the boiler pipe that's wasting money). They recommend 55 to 60 in winter and 50 to 55 in autum/spring.

The plumber who did my daughters gas boiler set it to 75 and said no need to balence the radiators. I have opened them all up. I hope he never fits heat pumps.

 

[Beaver]

To be even remotely efficient the whole house heating pipe work needs to be replaced with larger diameter pipes
35mm from heat source unit to cylinder
28mm feed & return ring from cylinder
Spurring of to each radiator in 22mm
Down to minimum of 15mm within the last 2mtrs distance to the radiator
Not efficient at all if just 15mm terminating to 10mm or 8mm at radiator