Heat Pumps! It's ALL About The Planning!
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- čas přidán 26. 05. 2022
- So many horror stories regarding heat pumps either not heating the property up or costing too much to run. Well it's simple to avoid this issue and have a nice (potentially cheaper) install.
Heat Geeks: / heatgeek
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Twitter: / evmanuk
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#heatpumps #heatpump #homeenergy - Věda a technologie
The most important thing to consider with home heating is Insulation, using the water leak analogy make the hole smaller. Many years ago, in a brand new house, the first thing I did was sort out the insulation, the walls were insulated with Rockwall, the loft floor with 12 inches of fiberglass , Every window had internal secondary glazing. Even the carpet underlay on the ground floor was 'insulating' . After the first winter I was visited by the Gas company who believed that my meter was faulty as I was using much less gas then the identical house next-door!.
When we had my mother-in -laws house insulated , using a Government grant, the gas bill dropped by just over 30%.
My current house was built with over the top insulation, from the 20 inch underfloor , through 200mm wall cavity insulation, to the SIPs roof, with of course the highest standard of windows available at the time.
Heating is through underfloor piping, via a ASHP which draws under 3 kwh .
It is all about planning, but starts with insulation.
no, insulation has NOTHING to do with it. insulation only tells you how MUCH energy you need, NOT how to make it. your radiators dont care if the water is heated by a heat pump or a gas burner.
@@SupremeRuleroftheWorld
The ‘insulation’ guy is absolutely right! If you control your heat losses it does not matter with what or how you heat your property, as you say as well. The only trouble is that most people do not have the money or knowledge to be able to insulate like this. And any government scheme only attracts a lot of cowboys who make a mess of people’s properties. I live in a flat which is trapped three ways between others, side to side and above, and my bills are very low as I benefit from others’ heat and insulation. I have not had my radiator on in the bedroom for over 4 years as the temp never drops below 19c. So insulation is definitely the way to go if you can manage it. And by the way, the government grant is limited to a total of 90,000 properties, there are 20,000,000 homes in this country, so it is a drop in the bucket. I doubt that more than 90,000 people in the whole of the UK will take up the offer anyway - so this ‘grant’, paid for by taxpayers, will probably only go to those well off to install these pumps anyway - so poorer people are subsidising richer ones!
@@petercollins7848
People forget the front doors, which is a big heat loss point. These are available insulated.
Well done!! Lots of things to think about. You are very diligent and precise with your research. Making a decision is all about having the details, for sure!! Cheers!!
As an architect I was learning that we need to be designing more efficient buildings 40 years ago. Yet in my professional career no client has been fully engaged with that need and until recently the phrase ‘only as far as building regs require’ was in common use by clients. With my phone (with LiDAR) and the software I use we can survey any building and model it in 3D and carry out that modelling thermally as well to assist us in determining where the most cost effective changes need to be made to the fabric to meet Building Regulations, BREEAM or PassivHaus standards. It even works with listed buildings and new ones too. The M&E engineers then have the information they need to design the most cost effective equipment to meet those needs. Yes it can be a DIY job but will probably not be the best solution for your needs, the chartered professionals are, obviously, better at that than the amateurs.
Because it all adds cost.
Domestic heating systems for average homes, like electrical installations, became rule-of-thumb. You can fit a high DHW flow combi with a low kW modulation (3kW and less), TRVs on all but one rad and have an OpenTherm thermostat/timer. Only need to do some simple radiator sizing calcs, which are online in simple fill in forms. An efficient rule-of-thumb system. People want the same with air sourced heat pumps. We are not there yet.
I also have a 1930 house. They were *designed* to leak air into the rooms to feed the coal fires. The cost of the insulation work required negates any sort of heat pump on the market right now (I only gave it a cursory look a year ago).
And the Scandinavian standard for building houses in 1930 was a lot more stringent for insulation than the UK was (probably was better then than we specify now!) so it's not comparing like for like, however good heat pumps are.
Everybody (heat pumps, Infra red, gas, wood burner) says theirs is the best. They are all selling. What we need is more of these videos that give us facts.
TLDR: Good video, good information, well done.
I face a similar challenge, plus I have a non-combi boiler system at the moment. I'm considering looking at an electric boiler after the gas one dies... fortunately a few years left before it needs replacing.
For an old house, insulation is more important than a heat pump. It's expensive, but will save you money every year. Insulate now and leave the heat pump a few years until your boiler needs replacing, when heat pumps will hopefully be cheaper.
there is the wrong thinking. lets gets 1 thing clear: the way you heat up your water for heating has NO impact on what insulation you have, your amount of insulation (or lack thereof) only tells you how much energy you need, not how to produce it. if you need right now 50kW of heat to heat your home for a day you will still need the same amount of energy regardless of how you make that heat, it being a heat pump or a gas burner. your radiators dont care either way.
@@SupremeRuleroftheWorld There is the efficiency of the heating method to take into account. Heating water with gas is much more wasteful, maybe 85% efficiency vs an electric boiler which is 100% efficient. So the amount of kwh needed is more with gas. Where you might be using 50kwh with gas it might only be 40kwh with electric. The heat pumps only produce a small amount of energy relative to fossil fuels meaning you need an efficient house to make them work well. Most old houses in the UK are simply not up to scratch without costly modifications.
Been an AC engineer for years. Best thing to do is keep your existing combi boiler with a cheaper air to air heat pump...
@@SimonHutson that's because they are much cheaper to install, having the option to also choose electricity of gas to heat you home is an advantage
can you explain sir?
Good video and timely as I am considering a heat pump to replace my 12 year old gas boiler. The property was built in the early 1950's, but it has been brought to a good standard of insulation. Last winter I decided to run my gas boiler at 44 degrees instead of the recommended 70 degrees with a view that we might be getting a heat pump that ran at that temperature. My home was still heated sufficiently in fact it was better because the heat was more even and not clicking on and off. This makes me fairly confident that a heat pump would slot in fairly easily with no major additional expense. That said I am getting a survey done as suggested.
I think I am fortunate that the original heating system was over-specified for the level of insulation the property has.
We put in a ground source heat pump in 2017 to replace our working oil boiler based system. We live in a 23 room 1800s stone farmhouse on the West coast of Scotland, drive two EVs about 25k miles a year, cook with electricity but have two 15kw wind turbines. Our previous oil boiler was used just like your gas boiler, it came on with a timer and attempted to achieve and maintain a radiator temperature of 60ºC and then switched off. Our GSHP is on all the time, all year. It has an external temperature sensor and also an internal sensor, we had to upgrade many of our radiators to double radiators as you are contemplating. The GSHP sets the radiator temperature based on setpoints for external temperatures of -1ºC and +20ºC. For example, right now it's 18.3ºC outside and the target temperature for our radiators is 20.4ºC for a target room temperature of 19.5ºC. So the system runs all the time, sampling the radiator temperature from time to time and then running if needed, and the house temperature is pretty much constant with the GSHP barely running in high Summer except to heat our hot water (I'm also considering a Myenergy Eddi to dump surplus power into the hot water tank).
Comparing our old boiler with a smart heat pump system like we have now is like comparing a hammer and a nail gun. The new system is able to be remotely controlled and changed, it keeps the house at a stable temperature all year round, no cold mornings and no "too hot to sleep" evenings. The old system was either running at maximum power or switched off and our oil bill in 2011, when an elderly relative lived with us and we had to keep the house warm throughout the day, was £200 less than our entire electricity bill will be for the year 2022/23 even at the new price cap. In fact our heat pump has already paid for itself, has increased the value of our home and has made it a far nicer place to be all round. Just my 2p worth...
They don't cool, so how is it 'not too hot'
@@Robert-cu9bm technically they can from what I've seen but need a special one
@@Burtis89
There is no reason you can't cool technically... But the manufacturers don't bother.
It's just a matter of valving and adding a wall unit.
No too hot to sleep evenings. What a load of BS. Not all of us are idiots you know.😂
Only 23 rooms
I am so pleased you're investigating the heat pump idea. I have retired to a new house in Nofolk having operated as a Consultant designer for many years and had an air-source heat pump when working before. What you haven't found out is in this country an air-source goes into defrost mode when ice builds up on the external coil. Under this condition heat is drawn from the house to melt the ice. Ice built up quickly on the coil meaning that it often goes into defost mode. It was a good job we had pv solar panels with the rhi payments which paid for the extra electrical cost. We now have pv solar panels and a solar iboost unit on the immersion heater giving us free hot water for 6 month's of the year. We also are on a seg tariff so get paid 7.5p/kw.hr for what we export. However I am most interested in how to avoid the standing costs of gas bearing in mind we don't use any gas in summer. I look forward to the next video. Bill English
Great topic EV, I'm definitely gonna follow your progress. Thanks!
Excellent analogy of the water flowing out of a hole in a takeaway container. A few things to consider, could one or some of the larger but too small radiators fit the heat requirement of another room & be re-purposed? You lose heat via droughts (air changes) & through heat loss through the fabric of the building. Tackling both of these, not just insulation would make sense, heat pump or not. The low hanging fruit on both topics could be easy, increasing in difficulty the deeper you go. I think we have been aware but complacent on energy efficiency, time to step up & get stuck in this summer.
If you need to go wider with a radiator, you don’t need to rip the floors up. A couple of elbows can increase the width of your valve spacing and job done. If you redecorate and redo the floor at any point in the future, the pipework can be simplified/neatened then.
Great video and has a lot of information I discovered before getting my ASHP fitted. My 1970's house has had most (13) radiators replaced, as single and without the extra fins, decided to replace as old and probably clogged up. Strangely several radiators were smaller than what had been in place before!
We have the larger bore pipework so all was great. Now the ASHP, uses a presurised hot water cylinder with a much larger heating coil to heat the hot water. This means great showers and no need for pumps!
However the ASHP prioritises hot water before heating, so if it needs to heat the water it does it, whatever the time of day. So cannot limit it to heat only at night. However the extra weekly heat cycle to 70C to get rid of any bacteria can be run at cheap night time.
From my experience I have used 1 or 2 kWh for hot water heating (max was 4kWh for one or two days in March).
Having solar, this can be the power for heating the hot water! BTW we are a family of 3 adults!
I had to increase my loft insulation, so now at 270mm but my wall insulation has broken down and needs removing and replacing. This is in progress.
For me I swapped from LPG, which had been costing 44p per litre but now over 70p!
It is great having no gas to burn any more, less risk of an explosion, Carbon Monoxide risk now gone.
I am interested how has your wall insulation broken down? Most rockfall stuff is glass based and doesn't deteriorate
@@roscopeco2000 I don't know exactly, the house is a 1973 build and we bought it in 2002. What I can say is it was a spray in that solidifies, but now if touched it just dissolves. Found this when the few bits of isulation came out of a new hole in the wall when fitting a new window!
Another great presentation Andy. Really given me food for thought. You are looking at this whole issue as an every day man with a good knowledge and research and that certainly helps people like me. The advertised high cost of a heat pump has probably put so many people off but as you say escalating energy costs leave us either just paying ( if we can) the increases, or look at the alternatives. Like EV grants the heat pump grant will reduce and disappear but if you have done every5hing else, best insulation levels, Led lighting and efficient appliances really there is only the various heating options left. Your video has inspired me to look at this topic in depth. Keep up the great content.👍🏻
I tackled the easy plumbing and radiator changes myself; we're awaiting a fuse upgrade and then getting a HP install. The BUS grant makes it almost a no-brainer. Older houses on smaller fuses (we're 60A) need upgrading and this takes the DNO some time it seems. Loved the water analogy for home heating!
Excellent video EVM. I've had a heat pump for a couple of years. My gas boiler was dying and my radiators were 35+ years old. I decided to change all the radiators as they were starting to rust. One further thing, houses feel much better with low flow temperature heating systems, either gas or electric, it's more consistent. Finally, beware the SCOP when thinking about water heating, to get your hot water to 55C, the heat pump ramps to 60C, so your SCOP drops to about 2.5 or 250%.
Good point, but it only needs to do it for an hour once a week to deal with Legionaires. With a big enought tank, you don't need to have the water so hot.
I found this really helpful and learned a lot. I thought there were special radiators for heat pumps, but it's just output. You made it all so simple. Thanks.
Great video, I absolutely agree you need to do the prep work before installing a heat pump, that’s a proper heat loss survey and where necessary upgrading the insulation. We live in a village that has no mains gas so when the oil tank sprung a leak last year my first inclination was to replace the tank (as the boiler was only 8 years old). However new regulations for siting of oil tanks away from buildings, sheds, boundaries, etc meant I couldn’t put the tank in the same place and I took the plunge to invest for the future in an Air Source Heat Pump. Due to the size of our house/system we needed an 18kW ASHP, which is not yet MCG certified, so we ended up with 2x 9kW ASHP’s running in tandem. The system was sized based on a 55 degrees flow temperature and about half the radiators needed replacing - if you can keep existing rads with a 40 degrees flow temperature then that’s brilliant; you must have a better insulated house than us !
The system automatically fires up if the hot water temp drops below I think 50 degrees so unfortunately can’t run hot water on cheap rate elec as you suggest - be interested to hear if others have successfully done this with an ASHP. As others have said, if you need a new wider radiator then a few elbow joints are all that is needed to extend the pipe work to the wider radiator, we had this done on some of ours and the elbows and pipework is all under the rad so don’t really see it - certainly no floor ripping up (we are all in 15mm so none of the core pipework needed replacing unlike your system).
Generally I’d say I am happy with the system, it keeps the house warm. The exception is the lounge where we didn’t want the radiator size they spec’d and it just never quite gets warm enough - moral of the story, do what the heat loss survey says, replace rads with the size they advise !
Finally, running costs. Our company recommended keeping the system on all the time as the heat pump is more efficient that way. We tried it but found that (a) it was too hot at night and (b) with the continual heat loss (your hole in the bucket analogy) the system does need to keep coming on and thus uses more electricity. Keeping it on all the time it was using about 80kW a day (£30). We quickly changed to putting it on a timer, and running it 6pm-11pm it uses about 27kW a day (£6.75) which I feel is acceptable.
We have solar panels but no battery storage so that is next on my list, to capture the solar electricity (and charge overnight) so can run the heat pump in the evenings for a much reduced cost
I’m hoping all my radiators are ample enough for a heat pump. We have 15mm piping on all floors of our 3 story 4 bed house. We can’t wait to get rid of our combi gas boiler. It takes too long to heat the water on the top floor as the boiler is under the stairs in the hallway. All our radiators are double convectors and 1200 x 600 in size. Most rooms are around 12 x 11 feet. You have opened my mind to having underfloor heating in the new kitchen extension we are having built. It’s bloody large at 4m wide x 7m long. More if a open kitchen, dinning, lounge space.
Hi Andy,
From one pink squishy thing to another, thank you for your techno/financial assessment.
Mike
Our landlord is installing an air source heat pump system into our house which he says is costing him around 12 grand. Can't wait, our heating currently comes from either a back boiler behind our coal fire or convector heaters. With the rise in costs now and coming it is needed and going to be very much appreciated
Brilliant and very informative....thank you!
Love your explanation of heat loss with the water in the Tupperware. 👍👍
Really useful video as I’m thinking about options to heat my house in the future. Fortunately for me Andy, you’re ahead of me on the journey, so I’m benefitting from the research you’ve been doing. (my Give Energy battery is due for installation in late July, so your videos on batteries really helped me to take the plunge). I agree that the cost to convert to a heat pump is currently prohibitive, but I see that Octopus Energy are working to bring down the price of heat pump manufacture, so maybe it’s not inevitable that installation costs will be higher in a few years time. Given the age of your boiler, it makes the decision to change easier. Appreciate the content and presentation of your videos; one of my favourite channels, for sure!
Great video and very objective. We had a ground source heat pump fitted last year to replace our 17yr old gas boiler. I did the same, got all the measurements and house plans together, the installer's came in and spent over an hour checking them and working out how to install it + further system design work back in the office. Of the 17 radiators in the house, only 5 needed to be replaced and even then 1 of those I suspect would have been fine. None required replumbing - if theres significant redecorating required to replumb a wider radiator, then there's always the option to try installing the largest radiator that will fit the existing pipe centres - worst case the radiator can be changed at a later date if it doesnt work albeit that will cost a bit more. We had a larger 300 lit water tank fitted and run that on the Eco setting at 48degC, and that works fine unless everyone in the house has a bath/shower at around the same time, in which case one of the higher modes (up to 60degC) is required. The system was sized assuming 45 degC heating circuit temperature, we find 42 degC works fine. In my view its only worth doing with a heat pump grant, so the install cost vs a gas boiler is the same after 7 years. I'm expecting the energy costs to be the same as the old gas boiler as I'm on the electric price cap, so should improve if I can get onto an Octopus Go type tariff. Remember SCOP figures decrease the harder the unit has to work, so the figures are greater in spring/autumn, or lower on a cold winters day or you run hot water at 60degC. Our decision was finally driven by the fact we wanted to find a way to reduce the CO2 footprint and use much less energy.
A side effect of these time of use tarrifs is that they are at night, the majority of people will be getting a air source heat pump and therefore they will work less well at night. So the kwh price is cheaper but you will need more energy input than you would during the day.
Given its 4x cheaper on GO off peak it won't be that much difference however.
back in the 80s I worked with a company in London that used to fit hot water systems for butchers and fish mongers using the freezer motors from their cool rooms. these worked incredibly well because the freezer runs the most at a shop . bonus being free hot water. . keep smiling everyone
But it's not "free" as you still have to pay your lecky bill which is going up and up!
@@mikehipperson
you also need to keep your products frozen
We have a 1950's cavity wall semi detached house with loft converstion and rear extension, with insulation blown in, on a previous government scheme. Then 6 years ago we had a Daikin Heat Pump fitted by a local company, replacing our previous Gas boiler that was 30 years old (We had a quote of £2500 for a replacement new Combi). It was suggested we replace 3 radiators out of 13, but those 3 were ugly old, tatty single panel rads anyway. The new radiators were less than £100 each fitted and look loads better than the manky old ones. No pipework needed to be replaced as we are 15mm throughout and 22mm under the floor.
We got ours on the old Feed In Tariff Goverment scheme, which meant we paid full price (£6700) but got money back quaterly for 7 years. We have broken even recently after 6 years and continue to benefit for another year. The running costs are lower maybe £300 per year, and we don't even have solar yet.
Hot water is only ever at 5.5p per Kwh over night and over 50% of heating is also done during this period, bringing the house slowly upto temp in time for 6:30am.
I have had no regrets and am very suprised more people are not opting for heat pumps selfishly from a money point of view. Personally I wanted to get rid of Gas completely from my house as all our cooking was already electric. We have been gas free for 6 years only paying the 1 standing charge for electricity, which also saves a little.
If I moved house, this would definately be one of the first things I would do.
My electricity bill, which is our only energy bill is now just over £1800 per year but that includes 15000 miles per year of charging our Tesla Model S. Over 55% of our energy is off peak/greener.
For us it works on a Moral and Financial level, win for us and for the grid.
I have done basically the same as you and it was one of the best thing I have done. I have added 16 solar panels and batteries. Now most days [summer] ,Octopus our supplier owe us money, this includes the daily standing charge. My monthly direct debit will now go towards the winter bill when the solar energy produced will be very low.
All these things are OK for people who can afford it, but sadly most people would not be able to. There are 20 million homes in the UK and the government are only giving out 90,000 grants over 3 years, then everyone will probably have to stand the full cost themselves. So many people who fit these systems don’t realise that they are well off compared to millions in the UK. Unless the cost of these systems come down they will never be taken up by the majority.
Hi! Very well made video and very wise to do the calculations before hand. I know my comment is late, but well, anyway. I live in Finland and my main source of heat for my 130m2 house + 50m2 garage is air to air heat pumps. I have electrically heated floors but usually don't need to use those, except in shower/toilets. It can get to -25 in the winter, and when its that cold, I need to use fireplace to assist with the heat pump.
The thing to keep in mind with heat pumps is that the advertised COP or efficiency fluctuates depending on the temperature outside (with air to air and air to water heat pumps, not talking about geothermal here). I think the advertised COP is calculated usually at like 5 or 10 degrees. When it gets -10 or -25, the efficiency drops. Depending on the heat pump, it might only do COP 1 or like 1.2 when the temperature outside is -25 degrees. Thats why heat pumps are usually oversized to what you really need, so that it is sufficient enough during the cold periods to heat up the entire house. Water tanks are used as a buffer, so that the pump doesn't star/stop cycle too much when its not so cold.
But I don't think you need to worry about extreme colds in UK. But heat pumps really do work, tons of houses heated with heat pumps and more coming every day.
I'm also just a consumer, not a heating engineer, but these are my findings on the topic.
nice aquarium, nice and clean-maybe you could do a vid on how you do it! lol
Thanks for the walk-thru on your heat pump instillation project, something I wish I had thought of before we upgraded our furnace just last year.
Good summing up. Been following Heat Geeks for a few months now. Great informative channel. Not tried yet but supposedly you can do the calculations to some degree yourself with their tools, at least get an idea any way
Was interested in the Octopus deal but I have microbore which they won't install on at the moment. Heat Geeks on their videos have said this shouldn't necessarily be a problem.
Agree with what you say about any quotes you get. If the engineer doesn't spend time measuring the house like you did and do all the necessary calculations don't go with them. Heat pumps are not something you can just chuck in and need proper system design
We live in Kent England and heat/cool our 3bedroom semi using Air to Air that has worked well for us now for two years. Still kept the gas boiler and all the radiator’s just as backup if it didn’t work out. We have two units that look just like air conditioning unit to you and I, cost us under £2,500 and installed in one day by two people. Able to heat the house in the winter and keep it cool in the summer. Cheap to run and in fact we run them off our 12 solar panels or off our Solax battery in the evening. We also have two electric cars that we charge from our solar system at zero cost. In fact when we installed them we paid £10,000 to have then fitted and took up the Fits government scheme which paid us to export any surplus at 28 pence a unit and it’s now paying us 58 pence and is indexed linked. What we generate has always covered our electric and gas bills, plus given an extra £1,000 a year in the bank. Bob Blood
Did you fit electric towel rails in wet rooms or still use the gas boiler for this?
@@Barry-xg1rd yes your right Barry that’s just what we did, removed the radiator in the bathroom and replaced with electric which is controlled from outside on the landing, also better in the summer when you can dry them quickly.
Perfect timing for me. Combi failing and getting quotes over next two weeks for replacement gas unit and ASHP to compare options. Really interesting and useful video. Thanks!
Best of luck. Even if you go with gas again, the heat loss calculation will help run the gas boiler more efficiently, too.
Keyword is weather compensation and getting it to condense all the time.
Great information, great video. The only thing I'd point out is with the water heater/immersion heater idea you have. I have an EV so I have the same cheap (Octopus) 4 hours at night to charge my car. For the last cheap hour the water heater turns on and heats the water up to it's highest temperature. The problem is, even though the tank is well insulated, during the day as you use the hot water the tank is topped up each time with cold water and cools the tank water down. So in my house by about 6 PM the water is only lukewarm and needs to be heated again at the higher electricity rate.
We only had to upgrade 3 out of 16 radiators, this is partly due to going for a high temperature heat pump and flow temperature of 50 degrees C, however we could reduce this temperature and prolong the heating period.
We also changed our hot water tank and we heat it during the night on Octopus Go. At the moment we only heat enough water at night for the morning and then fully heat in the afternoon with solar/battery power, in the winter I’ll go for 100% heating hot water at night.
Found it!
They call it a 5kw heat pump but actually it’s a 7kw.
Well done to Vailiant for giving a true output.
Lot of other manufactures don’t do this so true output is less at lowest outside design temp 🙌
Thanks Andy, Great episode.. You've confirmed a few things that I have thought about my house. All radiators are fed by 10mm plastic for example. This was a new build, so all the pipes are neatly out of sight. New 15mm copper isn't going to be and also will cause a lot of disruption to install.. So, I've been looking at Infrared heat panel systems. I know absolutely nothing!! So if you could do an episode... Seriously, great information. Great point to start my own investigations.. Cheers..
I’d second this... would love to see more opinions on infrared heating
And I'll add a third "yes, please" to that...!
There's a cursory video about Herschel Infrared panels on Fully Charged, but not in enough depth to make any rational decision.
A great video, we fit heat pumps.
They work, it’s simple technology TBH that everyone should have. We fix a lot of problem installs it’s nearly always the pink squishy thing that’s caused the problem.
We give a detailed quote based on some assumptions from experience, if the client is happy to move to the next step, we then charge for heat loss calculations and producing a quote.
We think it’s a much fairer way of doing it.
you could also look at something like an immersion using off peak + solar trickle top up during the day, or something like a sunamp for instantaneous hot water - again ‘charged’ off peak and with trickle solar.
Always start with an energy audit!
Excellent analysis on your housing energy needs. You should do the same for others and sub-contract your data entry and 3D mapping to your daughter (paying appropriate taxes, of course!). Or pay the daughter in popsicles. I'm sure you've done a better job than most commercial businesses do.
Very informative, I will certainly do a heat survey with heat geeks , then take your advice and get proper quotes . Thanks
I have just watched this video and thought I would share my experience. I live in a rural area with no mains gas and as such need an alternative way to heat the house. When we bought the house in 2017 it had a non working coal fired back boiler system and a defunct hot water cylinder. Prior to moving in we had a new roof fitted and immediately had 3.6kw of solar panels installed. We were quoted £12000 to fit a new back boiler system with a new hot water tank (not sure if that included new radiators and pipe work). I had heard about air source heat pumps so we looked into that as an alternative. We were quoted £8200 to install an 8.2Kw mitsubishi heat pump along with an ecodan ftc5 water tank complete with new pipework so as to ensure there was no muck in the pipes which would interfere with the running of the system. I also went with low temperature radiators which are much smaller and have a small fan built in to circulate the heat better. These cost about another £1000 to purchase separately but were installed by the air source people.
Our annual electricity consumption is around 3900Kw, which I think is pretty good for a totally electric property. I have no actual data to go by, as we have no bill history prior to the install, but can approximate that as we generate around 4000Kw per year with the solar and export about 2700Kw our usage without the solar panels would be around 5200Kw per year.
Air source heat pumps are a good idea, but unless you also have solar panels to offset the extra electricity being used, in my opinion they are not really cost effective unless you have no alternative. (We have neighbours who rent a property with electric heating and were paying close to £200 some months last winter. I dread to think what they will be paying this year).
There are also a few things to think about with an air source heat pump.
1). When the heat calculation is done it is for each room. Remember to keep all doors closed.
2). Don't believe all the hype about COP being 3 to 4. In reality ours is nearer 2. Maybe we are doing something wrong but I don't think so.
3). If you can afford it and are able to offset some of the running costs with solar. go for it, but make sure you have a maintenance plan in place just in case. I pay just over £300 per year but that includes an annual sevice of both the outside unit and the inside unit. This also covers all parts and labour (apart from a call out fee of £50) if any repairs are needed.
Just a note on Scandi heat pumps. Air source isn’t common where it’s properly cold, but deep bore geothermal heat pumps are common. Because of how life works, the heating system only fails when it’s the coldest out, so where winter days commonly hit -30C, people tend to have some backup systems in place
@Rikard Ottoson - Yes! The first working ASHP I saw in the UK was during frosty weather, and the outside unit was coated in heavy frost that prevented it working. Using an air source seems impractical if frost is likely - removing the little heat left in the air precipitates the available humidity as water, which rapidly turns to ice! Ground source is good, if deep enough, but there was a famous new car park at a UK shopping complex where the contractors just dropped the pipes into a shallow trench, back-filled it, and rolled the tarmac on (during the summer). Come the winter, the surface was all icy, with people falling over, cars sliding sideways, we got to see it on the TV News. Know what you mean about the way life works! If t can go wrong . . . . #8^)
My daughter lives in a new build house with a heat pump, it works fantastically well though the house is insulated beyond belief. I reckon a 100w incandescent bulb in the hallway would heat the entire house. She lives in Hampshire at 70ft above sea level while I live in the Staffordshire moorlands at 1000ft altitude in a house built circa 1850. Totally different ballgame, there’s no sewer never mind gas however in a modern house it does work well. Good vid.
Replaced our gas system with a daikin ashp last May. We've seen a saving over the winter period of around 20%. We were offered the option to either replace most of the radiators or fit a slightly more powerful heat pump. We combined it with a home battery system so we use octopus go faster tariff and solar pv. We're very happy with the change.
Yes, sounds good, but how much did you ‘spend’ to get your ‘savings’? It sounds a bit like the modern adverts where they encourage you to ‘save’ 50% or something, when in fact you are not saving at all but spending!
@@petercollins7848 well my boiler had died so I needed something. Cost was£10k but £7500 came from government and the rest was a 0% government loan, so £2500 was the cost.
@@enyaq_gorm
No, it came from taxpayers, and probably lots of them were poorer than you. I have nothing against the technology, but I am of the opinion that people converting to these systems should bear the full costs, because the ‘sweetener’ the government is offering is going to the well off by and large, and it is all just a front to make the government look like they are going for the green targets. The truth is that these pumps do not suit the majority of properties, and the government only intend to give out 90,000 grants over 3 years anyway. There are 20 million homes in the UK, and they haven’t a chance of getting the help they need.
I’ve got a ground source heat pump, not sure I agree that you should be paying for any quotes. I started the quote process during lockdown so they couldn’t come to the house at that time. I got 3 budgetary quotes based on me suppling the plans to the house along with some photos. The price range was large but just chatting on the phone and seeing what they did for that quote gave me a feel for how comprehensive their knowledge and design would be. None of them charged me but it gave me the info to be confident in my selection of installer. When I picked someone they came round but it was really to confirm things. The price didn’t change. We needed 3 out of 15 rads changed and it works brilliantly. Loss of the RHI scheme is really bad though as the grant is much less generous. I’d have done air source rather than ground source if we weren’t getting the RHI. Incentives going backwards when we’re trying to get to net zero is terrible.
I built a "green" house seven years ago. I told the "designer" I wanted a one ton forced air heat pump, so it would keep the humidity level low by running constantly. He told me that his "calculations" indicated a 2 1/2 ton unit was necessary.
Now my heat pump runs about 5 minutes. Then shuts off 10 minutes. Then cycles over and over. Pushing my electric bill up each cycle. And I have to run a dehumidifier all summer, adding even more to my electric bill.
Your advice is good. Hire an expert that knows how to calculate heat loss correctly. Or pay the price for years after.
What I've heard is you don't want that situation, as it causes higher wear and tear and (the compressor?) it's likely to die sooner than if it ran constantly.
Perhaps you can tweak the software or the thermostat higher to have the system run longer and dehumidify in the summer. Someone out there may have a fix for you, perhaps the manufacturer or their field rep. In the US we might sue the designer or their liability insurer. They goofed or were incompetent and should want to fix it for reputational reasons perhaps. If they are on social media etc. put your complaint there too.
Hi Andy
Another excellent video. Thanks for the explanation. I have recently fitted a solar diverter to my hot water tank so should not need to use the gas boiler as much in future. Heat pump or radiant heating is the next step so I echo the comments for a video regarding the latter.
We too are on a similar journey. Our gas combi has been punished on its last legs for over a year. Really wanted a sunamp and was quoted eye watering 18k for ASHP system including one. Sent me back to think. Made progress at Fully Charged, Emilie @ecobubl explained that a sunamp will only really work at higher temps so explains the high quote, included 8kW Samsung high temp unit, way over-spec for our needs. We’ve already had whole house external insulated so heating has been cut by over 30%. Octopus won’t entertain us as we are north of the border. Now got a date booked to have Scottish Power assessment. Now looking at using a mixergy as our heat store and MAY get an additional Givenergy battery to help cover the higher day usage. Think my sparky will tell me to get lost, not wanting to lift another 90kg into the loft 😅 Missus really liked the IR panels for boosting though.
Off-peak tariffs might disappear but I'm pretty sure that variable tariffs like Octopus Agile will become a lot more common. As we switch from gas to wind turbines the level of generation will be more variable and we won't be able to switch on gas plants to handle peaks in demand. We will need to use a lot more demand shaping.
Here in the US Northeast historically we have used gas driven jet engines as generators to meet peak demand so I assume you also do or can do in GB. But batteries will do the as well if not better, Home batteries and EV batteries can be tapped as needed with the right software. As just one example Tesla is signing up customers in Texas with his power-walls to participate in a pilot for batteries as a utility to feed the grid. They will of course be compensated for it. Like GB they have huge wind farms and the output can be variable and the batteries can take up the excess electricity as well. Off peak pricing may be available to tap into battery storage moment to moment with software and the Internet of things. The user can keep the power for their own use or sell it back at a better price.
Well, I made a system for the last winter totally by myself. Piping, fancoils, the machine itself, the automation, etc. It cost me about four times less than it would cost me to buy a new unit. I mean, the unit only. So, yes, it works that way if you know what you are doing.
If you get the rads changed now and lower flow temps from your existing boiler you would start saving now and when gas prices go up you wont feel it as much. After watching the heat geeks i turned down the flow temps and adjusted the timer
Vattenhall heat exchanger, for release this year. Temperature range of a boiler. Dutch company I think.
Goal to be used as a direct replacement for a boiler.
We live in a brick terrace built around 1876. Over the past few years I have been installing insulation above, beside and below, i.e. loft, interior wall and underfloor. Our gch has 10mm pipes which I am almost certain will mostly require replacing, unfortunately. The gas combi (pre condensing) boiler is now over 20 years old and has mostly been reliable with just one diverter valve and one heat exchanger fail in it's life. I need to finish my insulation project in the next couple of years in anticipation of the boiler finally failing and project heat pump beginning.
I also intend to replace one radiator in anticipation of need knowing where even with the gch boiler running at 60 degrees C the room feels not as warm as I think that it should. This is in the bathroom.
The big mindset change for switching to a heat pump is where for long periods the gch is off whereas the heat pump is most effective when run for longer periods maintaining a lower but consistent heat.
I'm hoping to get to Fully Charged Live this year to discuss heat pumps and the like with the experts in the hope that I will learn more and be better informed as we approach the changeover.
Another thing to consider timing-wise is lead-time. We had our heat pump installed in December 2021, and the regional supplier said that ours was the last one they had of that model that they were expecting to be able to get until May 2022 due to supply chain issues. If you replace the boiler before it fails, you can afford to wait. If it's a cold winter and your boiler fails, you might be able to get by with some hardware store electric radiators for a while, we did for a few days while the old heater was out and the new one was being installed, but probably not for months, particularly since those wouldn't give you hot showers, which might mean getting whatever is in stock, which might not be a heat pump.
I forgot to say, nice work on the video.
Something I haven't seen you mention about your conversion: Have you considered cooling? You mentioned wanting something that does it all in your video on why you aren't getting infrared panels; given the warmer weather the U.K. is getting, it might be a good idea to get something that can also run even one or two indoor air units upstairs or in key rooms to give you some relief on hot days. Pick a location for the indoor unit near an existing indoor drain pipe to connect the condensate drain to and you won't have much indoor disruption since the refrigerant lines and power both come from the outdoor unit and can run in conduit on the outside of the house. You might also be able to run the drain down an outside wall, though that's less than ideal since it's less efficient and can be a path in for insects. If you don't want something on an indoor wall, they make recessed ceiling units that can fit between ceiling joists too, though they're a little more difficult to install than the wall or floor mounted ones. Even if the weather now doesn't require it, you could make sure to get an outdoor unit that you can connect an indoor unit to in future if you decide you want to. It would probably be less than getting a separate mini-split system if you decide you need cooling.
That was one of the things that made the system we got work for us financially. We were replacing two pieces of equipment (furnace and air conditioner) that each were only used less than half the year, with one air source heat pump to use year round (...ish - spring and autumn have some pleasant days, but our weather tends to be rather up and down).
Think I need to point my daughter(s) in the direction of SIMS 4 :D - nice one, I hate doing CAD at the best of times - the pain of a module in AutoCAD at uni whilst doing engineering I think :s Great end-user review of the steps needed - unfortunately many trades (elec, gas etc) hide behind the smoke screen of thinking they know more than the homeowner so this is a refreshing insight into what's to come (you are far more clued up than most and prepared to learn) - gas fitters will need to up-skill and actually learn some engineering rather than calling themselves engineers when they have no engineering ability other than whacking the biggest boiler they can get away with and banging it up to 80C!
Very helpful.
One thing you missed , is that you can get a get a gadget like a MyEnergi Eddi or Marlec Solar iBoost
which will heat your water using any excess Solar you generate rather than feed it into the Grid.
I'm looking at a Heat pmp to replace my Gas Boiler , but in a couple of years time
As a heating engineer the biggest issue is oversizing. The system will not work properly if it's double the size it needs to be. A bit like driving a Lamborghini at 5,mph through town. It'll do the job but not efficiently and will damage the engine. Glad you got the calcs done and are seriously considering it.
Central heating in winter is the biggest component and the bit I worry about most - hot water is easy, it's a very small part of the overall system. In the coldest months of winter, my gas consumption is 20x what it is in summer when I'm only doing hot water + cooking (hobs, oven).
Like you say research is key, I'd be tempted to get an actual measured heat loss assessment during the middle of a proper cold snap, to see if your home's calculations match reality, you could have something that is leaching heat like poorly fitted cavity insulation for example, if you look at passive standards they have to be measured not just calculated, you also may wish to look at heat exchanger ventilation for your home as well?
Re the quotes, I'd recommend (to the point of threatening metaphorical violence) using the Energy Saving Trust to find approved firms. I've seen what happens when well meaning heating firms that haven't the experience try to estimate the required equipment and costs. Although it was more expensive to fit, I've had a ground source heat pump put into my own house, and an air source heat pump put into a smaller house nearby. Given the space I'd go for ground source but with the right equipment an air source is a good second. Incidentally if you have 'off peak' then an oversized storage tank is worth while.
Great video - thanks. I have recently bought solar panels and I am currently getting quite a lot of my saving from heating my hot water tank using solar rather than gas (my boiler is 40 years old so not the most efficient). I'm going to look at my year round generation before making any further heating decisions. An advantage of ditching gas is getting rid of the standing charge and the annual service (though I believe heat pumps need an annual service too?). My solar installers seemed to think that newer models of heat pump coming onto the market in the near future would be able to mean that I could do a straight swap for my boiler rather than replacing the whole system.
R290 heat pumps don't lose as much COP at higher temperatures and are then viable.
However, check out the SCOPs of e.g. the Varotherm Plus at 35°C 4.5 or 5 vs 3.5 is then well worth a once off radiator upgrade.
Always look at the big table in the spec sheet.
You can install the heat pump first and see if the radiators really need changing. I went from a system with a wood burning boiler that heated the radiators = high temp to a heat pump i didnt change a single radiator. I adjusted some of the thermostats on the radiators and thats all. Very happy with the heat pump. Heat pumps are very common here in Sweden.
You don't even need to install the heat pump to find out if your rads need upsizing. You could reduce the flow temp on your gas boiler to the same temp you'd be getting from a heat pump to see how your emitters perform.
So do you sti have your wood burner in as well as the heat pump can they work together?
@@shaun159 No, I threw it out when I installed the heatpump. If you plan on keeping the woodburner you need to be able to separate/isolate the heatpump when youre using the woodburner. The heatpump wont like the high temperature that the woodburner produces.
@@edalbagem thanks, I have a stove woodburner we burn Turf (Pete) here in North West Ireland with smokeless coal. But the stove does a good job heating the radiators and hot water, we also have an oil burner for the rads and hot water but I am leaning towards the heat pump and solar options.
As others have mentioned Andy, please have a look at infra red heating.
You will also be interested in the Mixergy tank, if you haven't looked already.
Keep up the good work, son.
(I'm very old so I can say that 👴)
Lovely house. Not all radiators are a standard size but it is getting better. Heat pumps are more expensive than you seem to think, and they cost a lot to install, probably due to lack of competition. we were quoted £9k just to attach to our system. Still, as you say its all negotiable. Good advice on getting your own survey.
Minus the £5000 grant it would be £4000.
@@ElectricVehicleMan
But the government are only issuing 90,000 grants over three years. There are 20 million homes in the UK. This is just a scheme that subsidises the rich at the expense of the poor taxpayer.
A tip to check if your house is ready to change over is the temp your boiler runs at if its under 55 centigrade then your radiators are fine, the lower the better it will work
We are about to install an ASHP to replace our oil fired Rayburn. It’s a no-brainer for us, given the price of kerosene. Our estimated SCOP is 3.8, implying our annual energy consumption on heating will fall to around 2500 kWh. Our existing solar PV and battery won’t have the capacity to supply this additional consumption, and our DNO is stubbornly refusing our application for additional solar. Consequentially, we’re looking at investing in a wind turbine via Ripple energy.
We have solar panels, heat pump, UFH, reasonable insulation. Direct debit charge has not risen by a penny since last year and is not expected to rise much later this year . RHI payments are flowing in too
That heat loss is the culprit. Most homes are so old with poor insulation that the first thing is to insulate.
For new housing they should go as the passive House builds.
Maybe a mixergy system combined with a Sunamp heatbattery would be a solution? You can keep installation the same.
Not sure if you really get COP4 on heating. Practical figures are around 3.
Do mind that every calculation falls when prices rise. So the first step must be cutting gas as priority.
We had a price on a new gas boiler and also we would need to have it moved to a new place in the house. This was quoted at £3600. Heat pump installation was £3500 for a 7kW pump and 180 litre tank. They said around £200 per radiator to be replaced if required.
thanks! now i'm gonna download Sims 4 and get my floor plan sorted!
Very informative, my gas boiler is about 8-10 years old, so it works fine, gas prices aren’t too bad, if the grant is in for about 5 years then in about 4-5 years I would probably look at one. But it is talking the wife into it, she doesn’t see the environment and cost benefits of off peak electric or an electric car, so this would defiantly not run with her at moment, waiting for couple of years 👍👍
It’s funny how we never think of doing the ROI for a new kitchen or a foreign holiday, yet talk about replacing the car for electric or upgrading the heating and immediately it’s ‘how longs that going to take to pay back your outlay’?
Lots of comments saying it won't work in poorly insulated houses. My house is solid walled, decent loft insulation, 20 year old timber double glazing. In summary - very leaky for heat. We looked at our options and in terms of cost, disruption and impact on energy usage/CO2 emissions, an ASHP to replace oil fired central heating won on all counts.
We've had an ASHP for 11 months (heating is off now, so I can quote an annual figure).
Central heating: 21MWh heat from 5MWh electricity giving SCoP of 4.2
Hot water: 2.5MWh heat from 0.72MWh electricity giving SCoP of 3.5 (we'll use a bit more as there's a month to go, but the SCoP will improve).
The house has been warmer this year than ever before because we've maintained a steady temperature rather than blasts of oil fired heat a couple of times per day.
It also doesn't spend half the time sucking energy out of the house to defrost itself either: the defrost cycle has run 751 times so far for just over 7 minutes per cycle i.e. around 15 minutes per day.
As EV Man says, it's all in the planning. Design a system for the building it's going in.
Great Video, very informative.
No use for where I live, rented flat dates from 11th Century, Listed building.
But interesting nevertheless.
Great video, issue seems to be finding the right installer which might be tricky. Heat geeks map is good but v limited coverage where I live
There are many issues with this video and although heat pumps work in Scandinavia, In the UK they have a habit of icing up in winter rain. Fabric of the building and construction methods play a massive part in change over costs. It's not unheard of for a 1990s 3 bed to end up around £20-25k for a system due to micro bore, chip board floors and having to locate the cylinder. Majority of engineers are happy to swap over to heat pumps, but it no longer becomes just a heating or gas engineers domain as an electrician has to be consulted to confirm if a premises electrical supply is adequate in the first place. As a 20 Amp minimum and often 32-50 Amp supply for larger properties heat pumps is required that in many cases is half of the total supply of the home. Baring in mind to avoid compressor issues and inefficiencies it's better for a heat pump to run for longer periods that can often be the choice between a heat pump or EV etc.
So from an installers pov, good video but far too narrow as the whole installation, pipes, heat emitters, tank location (if possible), flooring, incoming electrical supply, current electrical load, potential sited position for ashp, all have to be taken into account. One of the drawbacks many of our customers have found in the local area when hoping to go full electric is just the lack of available power to the property as most homes are on 80 Amp supply (18.4kW) or less.
This is just following my journey as I said. Not designed as a ‘how to’.
The icing thing isn’t a thing on the latest heat pumps.
The big issue with heat pumps over here in scandinavia now is their being used on all new build houses and its crushing the power grid. Last christmas 470 house holds lost power for 1½ days because 52 new housing units were running heat pumps on the same transformer as those others that lost power and it simply crashed. There are more and more places getting a no to install home chargers for cars and no to heat pumps because of this issue.
Well we should be ok in the UK because our grid is only at 60% capacity at high demand. According to the CEO of Octopus.
@@andrewmullen4003 Stats say about the same here for the back bone power grid nation wide, albeit quickly getting worse with the smaller private windmills and solar panels going up making it only just barely at requirement at peak for many rural areas. The local transformers and semi large stations are mostly under dimensioned for the new requirements, with all larger solar or wind farms needing a new back bone for them alone to prevent the normal housing grid from crashing. EU has just last week entered an agreement for 3 to 4 times the wind and solar power in Denmark and its estimated to cost 150 million euro just for starters to reinforce the power grid main lines. That's on top of the already ridiculously expensive line that's been going down from Norway to Germany so they don't have to stop windmills in Denmark when its windy in Germany or other way round if its windy in Denmark because here the power grid is already 40% under requirements.
Might as well upgrade radiators before heat pump, boiler will run more efficiently, house will heat up quicker and you’ll be more comfortable.
In Norway, Sweden etc. the insulation of properties hence heat loss are far superior to what the pre 2000 properties are in the U.K. Therefore, SCOP over there is viable.
what are you thinking about the gas supply. would you get rid of it (if that's possible) or go on zero standing charge tarrif. i guess your hob might be gas at least.
Do it, do it, do it NOW! 😂 We're into Day 2 of our new ASHP and it's brilliant. The heat loss calculations involved a 2+hrs survey and meant that we had to replace 4 radiators with 3 new ones (2 in one room if you're worried about the maths!). For the first time ever we can now go from room to room with no discernible difference in temperature and we no longer have the whoomph of the oil boiler firing up every few minutes. Our boiler was 16 years old and we were worried that it would fail in the coldest weather leaving us freezing while a new system was planned, slotted into a timetable and installed. How many weeks/months would that be? Definitely get at least 3 quotes. Only 2 companies out of 5 actually came to survey after I had supplied everyone with a fairly detailed description of the house, size, construction and insulation. The others would have come but I rejected their ballpark prices when they seemed about right on the size of Heat Pump required but were much too expensive. The first to survey was a national energy provider and they proposed replacing 7 radiators so that the total energy output would be 11.2kW......... and then they proposed a 7kW Heat Pump! Something was wrong! At the last minute whilst checking another supplier on the MCS website, I discovered an installer less than a mile away from me in the same village! He replied to my email the same day, surveyed the next day (Bank Holiday weekend), quoted the next day and I accepted it the following day. That was 3 May and last week it was installed. The moral, get several quotes, don't rely on big names and don't delay, do it today! Oh yes, excellent, informative video, by the way 😉
Two days.
That is a recommendation I’d follow. I was installing heat pumps 20 years ago but compared to two days in your case, and the nice man with a tupperware set, I will learn here for sure.
Thank heavens for CZcams and the expertise. This is what people call research. Perhaps if I watch more heat pump videos I will be eligible for a government R&D grant?
We have a heat pump, solar panels and battery storage. However, we’ve found that insulation is missing in parts of the house. The heat pumps can heat really well, the solar panels do not and will not power the heat pump. It also drains the battery fast, and I have 11kWh of battery storage. What the solar panels allow for is recovering the cost of the electricity used for heating later in the year. We’re around £300 in credit now (end of May) we use Octopus Go and heat the house at night for those four hours. We don’t do the hot water through the heat pump (yet) as we couldn’t get a hot water tank, but it is something that I am looking into now that I have somewhere to put it.
I do get tired of seeing people say that they don’t/won’t work. They work very well and it is way more efficient that our boiler ever was, and it isn’t an old boiler, the biggest issue is the lack of insulation in homes in this country.
The biggest worry is just how complex the the system will be. Also very little is produced in the UK. If something fails, you may have to wait for spares.
5:18 With the heating off the inside temp does not drop down to the outside temperature.
Houses trap the sun's heat in the day and retain some of the heat overnight. Typically it's +5C warmer indoors in Winter than outdoors.
If the heating is switched on again the next day. If it isn't it will fall to ambient eventually.
The sun regularly shining on the house warms it above the ambient temperature, plus there is no windchill indoors. The temperature loss is much faster when there is a big temp difference, so without heating on you lose very little heat.
I've lived through a mild winter with no heating on, and I can attest that the inside temp is consistently about 5C warmer than outside.
If Russia cuts off the gas supply most of Europe will experience this soon.
And I've lived for the past 6 years with winters where I heat the house to 10 celsius during the day and overnight it falls to ambient. As the video states, it'll be different for each building, it's just an analogy to illustrate a basic premise.
Great video, very informative.
Have you looked into Infrared Heating Panels for heating? Herschel or Jigsaw panels? Maybe a Sunamp Heat battery for your hot water? All easy installs that can be powered of solar/battery with minimum maintenance. I'd be very interested in a comparison video.
Cheaper to install. More expensive to run.
One other thing to think about I’d say is that your time of day tariff might not make sense anymore. Obviously depends on your specifics but I noted you said you are paying 30+p/kWh through the day to get the 5p/kWh over night for 4 hours. Your experiment shows that to get best efficiency you need to have the heat pump on all the time. It can be more efficient to leave it on even when the house is empty as raising the temp is less efficient than maintaining it. That means your daytime electricity use could increase to the extent that it outweighs the benefit of your 4 cheap hours with a more expensive daytime rate compared to the cheapest all day rate. It’s not going to be the case for everyone but is for me (even after I factor in the battery I’m getting installed) so worth doing the sums to check. I think others have said as well, you are unlikely to get a SCOP of 4 on hot water due to the higher temp needed. Most heat pumps will quote different SCOPs for heating and hot water
he said around 35pkw day/ 7.5pkw for 4 hours at night - trouble is he has a Tesla M3 so it may still be better as he is as the car will use a lot depending on his mileage of course.
@@markreed9853 yeah I couldn’t remember the exact figures and didn’t want to search for it. I’ve got an ID4 and a GSHP and 27.9p/kWh all day is cheaper for me but that won’t be the case for everyone. Point was to just not assume the time of day tariff will still be the best option. Need to do the suns to find out
@@markskene8226 ...just remember he has solar and batteries as well so that's a factor as well.
Upgrading radiators is easy but remeber to get your system proffesionally flushed. Most plumbers will not do this properly. Ours did bugger all and charged us a fortune. To do the job right requires either the removal of each rad and flushing out outside. Then the pipes flushed by high preasure water too.
I Had 3 quotes for an ASHP. One recommended a 13kw based on a visit from a salesman and one an 11kw pymp based on an email. Octopus Energy did a 3 hour survey with two heating engineers and recommneded a 9kw heat pump and identified the radiators that needed replacing. They came in at more than half the price of the other quotes. It is difficult for a lay person to really understand what is reasonable.
The simple rule I would use is:
Get 3 quotes.
Salesman cannot design a system, only a heating engineer can. If they don’t spend several hours work to just give you a quote then walk away.
Surprised you didn't mention your existing battery. You can and probably already do charge that battery at night during the cheap period. With a higher capacity battery you could easily "offset" at least half of your winter on-peak consumption requirements and further reduce your bill. For comparison our house (ASHP and UFH) uses an average 27kWh per day during the coldest parts of winter (about 17kWh during peak).
As an energy efficiency advisor when you said you would need to change the top floor pipes from 10mm to 15mm, I have something for you to think about. With any wet heating system you are heating the volume of water within the system by making your pipes larger you are adding more water to heat within the closed loop also the use of 10 mm pipes is to help raise the pressure on the top floor. So would not recommend changing them. Before getting your next quotes. The likely hood of the heat pump grant being around in its current form looks like it will be changed in the next 18 months or so.
Having more thermal mass in the system surely helps prevent cycling also the volume in those pipes is tiny compared to the rads
So, the reason to replace the 10 mm pipes would be that, at a 40 C water temperature, they can't deliver heat fast enough to the radiators to make up for the heat transferred to the room by the (larger) radiator; at least not without unacceptably high flow rates. The static pressure of the system is irrelevant. The energy required to raise the water in the system to working temperature is irrelevant because it's effectively a one-off; heat pumps tend to run more or less continuously in a well-designed system. Even if the system is shut down, that energy will eventually make it into the building so it's nothing to do with the efficiency of the system.
Been thinking about this a lot lately.
When you need to change radiators and/or piping, would it not be better to replace those with infra red heating panels instead?
Especially if you have a battery you have can fill with off peak electricity?
In other words a Hybrid system Heat Pump/Infra red panels.
For the HW - is the proposal just an unvented cylinder that is heated via the HP or a thermal store which would might make more sense for you as you can then 'charge' it via the PV, battery, grid or HP whichever is best value and then draw it off for CH and HW? There may be more losses I guess but when you have multiple inputs and outputs for energy then energy is energy at the end of the day!
A great video explanation.
What software or service did you use for your heat loss and radiator sizing calculation? I have a renovation project on a Victorian house and would like to run multiple scenarios to guide and make the key decisions with my own basis, then engage professionals for the detail, then also allow an understanding of incremental changes and new 'what-ifs'.
Insulation is the first thing you must do. Even if you stay on gas, reducing your energy requirements is number one.
Hi Andy, good video, have you thought about IR panels such as from Hershel?
Not that long ago, you mentioned that heat pumps weren't for you. Interesting to see after more research that you had a change of mind.
Had Octopus come out this week. They spent over three hours measuring romms and radiators etc.
Unfortunately I was flagged red on their survey as I'd need scaffolding for the install, and more significantly the tank size wouldn't fit in my airing cupboard :-(
Thanks
good job Alice
Maybe use a Sunamp for your hot water rather than a big tank?