How to Generate The Most Efficient Hot Water On EARTH

Unlock the ultimate efficiency secrets for hot water cylinders in our latest 2 part video! Join Adam as he unveils the steps to creating the most efficient cylinder...in the world. Make sure to watch part 2 for the full picture!
Part 2 ‘Controls’ - coming soon!..
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[@PaulJones-t7w]

Seriously, this man should be in line for an OBE. Over the last few years he's been dragging the culture of air2water heat pump installation in the UK (kicking and screaming?) into the place it needs to be - where it's trusted, efficient, and reliable. If this was left to the government, we'd be years behind - just look at the miserably low standards of MCS for heat pump installations. And all done for the right reasons - 1. because we need low carbon home heating; 2. giving installers the self-respect and pride that comes with doing a top notch job where they actually understand what they are installing, and 3. helping interested home owners understand their own heating systems. Massive respect and gratitude.

[@imnothere220]

Point 2 is a huge one.

[@upnorthandpersonal]

Here in Finland, I use a different approach: the heat pump is directly coupled to the storage tank without heat exchanger coil. The domestic hot water is extracted from the tank with a coil. This means that the water in the buffer (in my case, 3000L - yes, thousand, not hundred) together with the heat pump circulation and the underfloor radiant forms a closed system (and contains propylene glycol antifreeze as well). The stratification principle is used by putting the domestic hot water coil all the way at to the top of the tank. The heat pump always gets the coldest water from the bottom of the tank. I'm off-grid, so there is also a wood gasification boiler coupled to the tank for those months where I don't have enough solar to heat (no sun in December and -30C), but otherwise this time of year (still close to and below freezing) I just dump all the excess solar power into the tank with the heat pump and I don't need any wood.

[@JoeFoster]

So a thermal store rather than a stored water tank? Not common in the UK but I did have a boiler which had one of these once, was a bit of an odd system but had great flow rates

[@upnorthandpersonal]

@@JoeFoster Yes, because the wood gasifier is rated at 40kW, and it's not something that is instant on/off - so you need a place to store the generated heat. It can pretty much heat up the entire tank to 80C on a single firing.

[@andrewmillwardwatford9410]

I had thought about using a similar system for my home in Estonia. A large heat stores mainly needed because of the wood firing and I guess in your case if you have a particularly good result from your solar system. I was going to use weather compensation via a mixing valve from the heat store have you done this too

[@PeterJFlower]

I did a large thermal store in Britain about ten years ago for a sports pavilion. The big problem was trying to stop it scaling up, the water was hard in the area and eventually the water wasn't getting hot enough in the coil. I tried several scale inhibitors before fitting four Cistermiser Combimates in parallel (on the 2" cold feed) which seemed to work, I never heard anything after that. Is it still ok? I'm afraid to ask.

[@upnorthandpersonal]

@@PeterJFlower Yeah, that's an issue with hard water. My well water goes through an ion exchange filter, so it's soft - no issues with any buildup.

[@robwoodcock8566]

I was involved with a company which invented Heat Pumps to cool Cellars (mainly pubs) and heat water . We used various cylinder designs. We could provide all the hot water for 12 bedroom hotels and busy pub kitchens just from one cellar!

[@metalhead2550]

"We encourage other manufacturers to take our design and improve upon it" Does that mean you're going to open source or licence your design to these manufacturers? :) I love the collaborative approach you have embraced to push the whole industry forward! Keep up the great work!

[@HeatGeek]

Yes exactly that.. part 2 gives even more away..

[@matthewasanan]

How do we get a hold of the open source drgs and/or cad model? ​@@HeatGeek

[@999fugazi]

Amazing work, definitely up for one of those cylinders when I have my ASHP put in later in year. Well done. You are the Martin Lewis of Heating Engineers!

[@robandrews9826]

Ive been interested in heatpumps for over a year now, watching your videos along the way, finally starting to see some real difference going on lately, keep going guys!!!

[@albex8484]

I use a heatpumpboiler. It's set to 52 degrees in the night. In the morning it goes to 60 degrees. Even in the winter, my solar panels give enough power to give me free warm water. Most is controlled by Home Assistent and Shelly controls.

[@hughrattray9354]

Excellent work - I would add another requirement for the ideal tank and that is the ability to see how much hot water is in the tank. I find myself having to do hot water boosts just in case we might run out - this is a waste of energy if there is enough left in the tank.

[@aerenewables]

brilliant video as usual !! fitting that cylinder tomorrow can't wait to see how well it performs😀

[@wardy89]

My parents have just had one of these installed, so far the performance is very impressive.

[@1973DACH]

Bravo - I wish I had found you 5-6 years ago !! Could have saved us so much cost, frustration and increased our scop !! Having had 2no 13 kw SE GSHP installed - now trying to get a heat geek round to review & refresh & maybe install a energy monitor -

[@Koopris]

Recently retrofitted a Willis heater to my vented cylinder to dump excess solar. Beautifully simple design working on natural thermosyphon. Heats from the top of the tank down, maintains stratification due to low flow rate. Also ensures that what excess solar you have goes to usable hot water in contrast to a traditional immersion element.

[@andrewmillwardwatford9410]

How did you plumb your Willis heater?

[@Koopris]

@@andrewmillwardwatford9410 the Willis is next to the tank with the cold inlet as low as possible and parallel to the tank's cold water feed. This ensures the Willis can heat the whole volume of the tank before the thermosyphon eliminates itself. The hot side of the Willis is piped directly up and teed into the tank's vent pipe. To prevent reverse flow or unwanted syphon when the Willis is not heating I added a radiator valve driven by a UFH actuator to the cold inlet of the Willis. This js powered from the same supply to the immersion element. Used a 1kW element, contactor driven by a Shelly relay which is in turn controlled by some logic around battery state of charge etc. Basically a poor mans My Energy Eddi.

[@BristolHeatPumps]

We include these in most of our quotes now, such a great bit of kit and much better than alot of manufacturers own brand of cylinders.

[@annedreikandt7361]

How does it compare to the Vaillant UniStor?

[@BristolHeatPumps]

@@annedreikandt7361 much better performance in my opinion.

[@HorizonimagingCoUkPhotography]

A fascinating, well-presented and feature-rich video as always! Thank you HG! 🙏🏻

[@anthonysalisbury6945]

Another really good video and really informative. Always thought no one really has a handle on the "engineering" of these systems, loads of opportunities to become more efficient. I have a solar coil in my tank but never used it.....never really thought about plumbing it together with the main coil to increase the surface area 🙈

[@xxwookey]

I spent a lot of time looking into stratified cylinders back in 2008, mostly from the point of view of maximising solar thermal input. The only tanks one could buy with the right characterisitics (internal stratifiers, input diffusers) were German, Dutch, Finnish and mostly huge and expensive. (Consolar, Solvis, wallnoefer, Tiso, Akvaterm etc). I considered making my own as no-one was selling a UK-sized tank designed to stratify nicely (for less than 3 grand), but didn't trust my welding skills enough. So I ended up just using a side-mount plate heat exchanger to load a standard domestic cyclinder from the top. This has actually worked pretty well for the last 15 years. You get less total energy transfer but more useable hot water without having to turn on additional heat inputs. So 3/4 of the year 40 tubes does all our hot water (2 people), and the entire solar thermal system plus tank mods cost about £1000.

[@johnh9449]

That's interesting Adam. My natural instinct would have been to think that a de-stratification pump would increase thermal transfer and efficiency - but as you say, it's better for the heat pump transfer from the coil if it's in the coldest water. Following that but less significant would also be that the flow enters the lower end of the coil and exits its top. I'm glad I don't have a de-strat pump now. I have a tall 300 litre Joule cylinder specifically designed for heat pumps with a bigger coil. I've set up my Midea heat pump to heat to 50°C during cheap electricity times at night and once a week to 60°C for Legionella - avoiding use of the immersion heater which is only 100% efficient. I did get an Eddi solar diverter but since the export tariffs pay at least twice the cheap rate now (e.g. 15p/kWh export and 7.5p/kWh import on Octopus Intelligent Go) it makes no sense to heat the hot water with solar PV using the only 100% efficient immersion heater. Although it's "free" it would just stop the tank heating from the heat pump at night because it would already be hot and I'd lose out on the 2:1 tariff profit advantage which if I'm running a COP = 3 effectively means a COP = 6 in cost terms. The Eddi is now only used to monitor the tank temperature at the top (the heat pump monitors the bottom) and timed to top up the end of the Legionella cycle if the heat pump can't quite get to 60°C but it usually gets to 58°C or so so there's little point in topping it up.

[@johnh9449]

I've just checked and the flow to my coil is at the top and return comes out the bottom. The Joule brochure shows them this way round too. Would it be beneficial to swap them round and how much difference would it make?

[@InkeyInc]

Excellent explanations, and another informative & interesting video. The logic further reinforces why I've had poor performance with my 200L HORIZONTAL tank. There is essentially no destratification in the horizontal position. I'm further guessing the heat exchanger is going along the inner circumference of the tank (up-down), thus not transferring to the coldest water in the tank. Possibly great distortion but at the cost of lukewarm water when cold water mixes so well that it decreases overall tank temperature quickly. For tank design, besides tall-skinny-vertical, it may further help to have baffles to reduce cold water convection at the water-in.

[@brotherjohnno]

Thanks Adam, always interesting.

[@71brp84]

I have one of these cylinders, along with a Vaillant 7kW, being installed in 2 weeks by WDS Green Energy. Quite excited really.

[@RicknessJ82]

Awesome video, thanks for what you are doing to push forward the quality of installs and systems. Aside from the things you covered, one thing that robs my system of performance is the length of pipe between the heat pump and cylinder. Using large diameter pipe which is good for flow, unfortunately increases the volume of stranded hot water in those pipes which is energy that is delivered by the heat pump that never really makes it to the cylinder (mainly an issue when space heating not needed). Also, this would not likely show up in the COP numbers the way they are measured. But having a big store (that doesn't need to be reheated many times a day) and locating it as close as possible to the heat pump would minimize. I was reusing the indirect tank from my old oil fired boiler setup to save on equipment/installation costs but in the future I'll definitely be targeting to get a larger tank with a bigger coil, locate it closer to the heat pump and expect to see a significant reduction in energy use!.... Or people will enjoy longer showers and baths, we will see ha.

[@ideasinprogress607]

Have you considered adding a phase change material in a closed pipe inside the cylinder? Perhaps even wrapping the coil around the phase change pipe to ensure it stays "charged"?

[@ianparkhouse-ew8qz]

Good learning here, I was surprised to learn slimline cylinders are more efficient because I’ve just been looking at their higher thermal loses but this make good sense

[@HeatGeek]

Thermal loss is very small, especially at low temp

[@glisterservices]

Great video Adam! I hope Vaillant have done something similar with their new range.

[@i85_Heat_Pumps]

Looking forward to fitting one of these in the next few weeks 💪

[@JemFreiesleben]

Been waiting for this since the previous video - thanks! I have a lot of height but not much space, would be interested to see what tall slimline options are in the range.

[@davidhayhurst7044]

Interesting stuff. Like the videos. As an architect involved with sustainable design it's really interesting to hear your perspective. I can't replace my own thermal store, but it has made me wonder again about the settings. Overall we use very little energy in our all-electric low energy home, but I'm always looking for efficiencies. Currently we heat 1/2 the tank but I am about to experiment heating the whole tank to lower temperature to see how that effects consumption o/a and DHW flow temperature.

[@xxwookey]

So it's great to see these principles finally reaching UK heating design. And obviously the optimisations are slightly different for a heat pump than a solar-thermal+gas input. A couple of things you said seem a bit odd. 1) putting the coil as low as possible is good to maximise heat transfer, but isn't it also good for disturbing stratification? If you feed in the bottom of the coil to maximise heat transfer you now warm the water right at the bottom which will rise and potentially cause mixing. Have you just found that it doesn't (mix) and stratification is maintained? Or are you putting the hot in at the top so that it passes through the already-warmed-height before finding some water cool enough to warm, and thus most of the heat-transfer occurs near the thermocline so there is less mixing? 2) Is a 'wide input pipe' really sufficient to prevent destratification? All those tanks above have fancy diffusers or separators to prevent incoming cold water (or warm water from heating systems where the tank is used as a heat store too). I'm a little surprised that just using a (28mm 35mm?) input pipe is sufficient. Obviously you have data showing that your setup is working, but are they really not putting any sort of diffuser/baffle on the input? 3) You advocate as big a tank as possible. Which is indeed good for optimising stratification and heat store capacity, but standing losses are quite significant from hot water tanks (1-2kWh/day) so especially if you are a low user you start to lose more in losses than you gain in efficiency. has anyone got any sums on this? I find these things tend to be optimised for households of 4 or 5, getting through 200l/day of hot water. If you are only using 20l/day then I suspect a smaller tank comes out better overall.

[@HeatGeek]

1) you want the hottest heat heat source against the coolest water. This or plate loading are the only way 2) ‘wide pipe’ is the same as a diffuser etc- any way of lowering the velocity- I’ve just worked with what we had available. I’m sure it could be improved but is currently the most efficient cylinder 3) the standing losses are smaller than the free energy from increase heat pump effy

[@SkillBuilder]

surely solar thermal is a match for this in terms of efficiency. The heat pump compressor consumes more electricity than a circulating pump on a solar thermal unit.

[@HeatGeek]

Add the words on demand to the title.

[@kaf2303]

Thank you for this site , I enjoy your content!

[@meineszmf]

When do you start in the Netherlands, 🙏🙏🙏

[@tomslocombe]

I watched this with interest. We have a small cupboard which houses our existing tank and gas boiler. One of the main obstacles to installing a heat pump is the requirement to fit a larger diameter tank. These new tall, slim tanks may fix this problem. The 200L tall tank would fit the bill, but still may not fit due to the external plumbing, valves, immersion, etc. Practically speaking, how much extra space is required around the tank to plumb it in?

[@BobHolroyde]

Love your vids, thanks for sharing all of your work. Im not a Pro, but I have a question. You state that to be more efficient, you need to get the heat pump water into the cylindar with an eliment or external plate heat exchnager and the lowest Differential Tempriture. Why would you not use a couple of eliments for your Hot water, direct from the mains to take heat energy out of the tank to DHW. The water in the tank can then be common with your Radiators or UFH? So no temperature difference between Heat Pump and Cylindar. Benifits as I see them. You can layer the water in the tank and heat it gradually from the top down. No concerns about Legionela as the water you use is not stored. You can use a lower tempriture so long as the tank is big enough. The DHW tempriture is consistant regardless of the Tank Tempriture. Obviously needs a thermostatic mixer from the cold. The system is sealed and has with inhibitor, so less likley to build up limescale. The DHW eliments can be cleaned without having to drain the entire system. You can use other heat sources, wood, pellet or gas boiler, or Thermal Solar (via another element). Very happy to have it explained to me why that's not efficient or not a good plan. 🙂

[@lokawong9740]

I simply used 3phase electric heater to get instant hot heater as much as I need (instantly adjust the temp. too), no pre-heat or afraid of temp drop for un-used hot water. The installation takes few hours instead of days, the whole setup less than £1000 (Given the house is 3phase) I do hope it is commonly avaliable in UK. Truely wanted to get into the field and promo it.

[@BenIsInSweden]

3 phase isn't common in the UK. Also at the price of electricity in the UK doing 3-phase immersion would be super expensive.

[@davidstorm4015]

Great video, why aren't there more people doing what you do?

[@martinallen5494]

And why is the immersion heater positioned where it is? Would there be any advantage to positioning it lower down the cylinder? Thanks.

[@michaelsheridan5606]

Hello Adam, any plans to design a super efficient cylinder with 500ltr capacity with a solar coil to go with the heat pump coil?

[@Geyer128]

There are also hot water heatpumps, that run fresh water through them

[@barriedear5990]

We just had a new install using existing Joule cylinder With 1.1m2 surface area coil. Installer chose to use just external plate heater, when I thought he was planning to use both internal coil as well as external plate heater. Which setup would work best, in your opinion.

[@elringoRS6]

Part two ready yet?

[@JP-zd8hm]

Is there any long term degradation caused by scaling of the coil when regularly heating above 60C to benefit from low rate electricity?

[@rolandrohde]

Hot water is indeed the Achilles Heal on my Arotherm system. We have the "Unitower" Setup and I think that just isn't a efficient as it could have been with a better cylinder. It was the way Vaillant planned the system for us though, so nothing to be done about it at this point without massive extra cost. It's not that bad though, because despite having a relatively bad COP on hot water (usually in the 300+X% range) we only use 0.8-1.2kWh of electricity per day in the warmer seasons to heat up to 50°C..of course it's more in winter, but not ruinous...😉

[@Leo99929]

My boiler broke and I immediately assumed I'd replace it with a heat pump. My heating requirement experimentally is in the order of 3.5kW in the depths of winter. Should be a no brainer, right?! No. Turns out that my electricity is about 24p/kWh and my gas is about 6p/kWh, it works out that I need a CoP of 4.2 to reach cost parity, let alone any saving. Yes, I can disconnect my gas main for a little bit, but I have a gas BBQ and gas forge that would get very expensive to run off bottled gas. I could try and get a special tariff and shift my consumption/usage to off peak times. But this doesn't move the needle enough to know that it will cost equal or less to run before I install it. I might have to spend thousands on upgraded radiators, glazing, and insulation, in order to improve the SCOP to a level where it makes financial sense to spend more than twice the money on a heat pump. Or buy a battery as well which more than doubles the installed system cost and does pretty much guarantee savings... The problem is that gas is subsidised to lessen fuel poverty killing people. Electricity costs are inflated to cover it. And the difference means that heat pumps by them selves struggle to make financial sense. I want a heat pump for moral environmental reasons. But I'm not rich enough to be able to increase my fuel costs to do so, or invest enough up front to make the maths work. We need cheaper electricity, and more expensive gas. Maybe with assistance for those who are really in danger from fuel poverty. How about knocking VAT off insulation and glazing? SOMETHING! The only people who qualify for the current schemes are those who can't afford to take advantage of them. And they wonder why take up of the schemes has been so low.

[@metalhead2550]

Do you have any data on reheat times etc. so the cylinder can be compared to others? Also have you had any performance figures certified by an independent lab?

[@myatix1]

I totally agree! If the Heat Geek cylinder is so great put your figures to the test through an independent lab.

[@HeatGeek]

That won’t account for the variance of real life. Follow the open energy heat pump monitor for real time results on hundreds of properties across the uk.

[@brianballard905]

As long as his instruments on the open energy monitor are calibrated how could an independent lab do anything differently?

[@martinallen5494]

Is the tank suitable for well water?

[@yellowgreen5229]

This is crazy to use coils, use an intermediate heat plate and pump and a tiny heat exchanger can have the effect of a huge pipe heat exchanger and massively reduce materials.

[@HeatGeek]

You need an extra pump and various other parts. More parts the plate load then coil

[@f2air]

Very interesting video. How is the heat pump F&R ∆T affected using the larger coil? Manufacturers typically state an optimum ∆T of 7°. Have you also monitored the heat pump to see if it maintains and/or improves efficiency? You probably alluded to this question when talking about the HP Saturation Point. You're doing great work by the way, I deal with a lot of opinions on HP design daily! (MCIBSE)

[@richardlewis5316]

Years ago I had a hot water cylinder running off a pre combi boiler. Gas was cheap so the fact that I was heating 30 gallons of water was not important. But now heating that much water for a shower would seem insane yet that is what I read (and see on U Tube!!) is what is required to enable a heat pump to supply hot water. Houses often do not have baths so an electric shower is all that is needed for hot water. Room heating is not needed for 6 moths of the year (UK) and then only when cold snaps occur. So how can a heat pump be justified?

[@swisby3820]

How can hot water stored at 40 to 45C work with thermostatic mixer valves that most state that the hot water flow needs to be 10C above the desired outlet temp for the valve to function correctly? I noticed that most of the top performing open source energy data figures are using low temperature hot water storage that will obviously improve CoP. Also previous videos discussed legionella risk and stated 45C absolute min?

[@HeatGeek]

Please watch our legionella vid

[@taffygeek]

With smart controls and Tarrifs the cylinder will act as a "battery". I get notification of 50% discounts on windy days. Cost wise it would save me money to "overheat" hot water. It would lower the COP but save money.

[@HeatGeek]

Part 2 addresses this. There is a better way to

[@brianmead5102]

Can a hot water tank be placed out side

[@chadreid9305]

@heatgeek great video, love the detail. Just wondering if it is sensible to combine solar thermal with a heat pump, maybe use the solar thermal as a preheat for the main hot water tank? What are your thoughts?

[@HaggisMuncher-69-420]

Do you guys offer consulting for international folk? I moved to Romania from the UK and desperately want to get a heat pump installed but I'm not very familiar with the insulation of our house in a rural village - it's nice and cold in the summer though so there's that. We're currently heating with a wood stove until I can figure out what we need for a heat pump - also going to more than double our floor space with an extension soon so will need to future proof.

[@adrianborton5736]

Been watching your stuff for a long time now. Why can we not have a changable uv lamp to remove the risk of legionaires building up in cylinders so we can run a low flow temperature and stay safe.

[@digitalfantazia3953]

Hmm I wonder if a swirl pot with holes in it might work with regards slowing down cold water input

[@michaelwinkley2302]

Any idea when we get to see part 2?

[@justatiger6268]

Does it have a protecting anode?

[@londoner6040]

Why are there no prices on Newark's website? No need to have a different quote per person for the same size surely?

[@NewarkCylinders]

We'll have details on our site later today.

[@londoner6040]

@@NewarkCylinders Thanks! If it's a comparible price to the others I'm being quoted on it'll be an easy buy.

[@NewarkCylinders]

@@londoner6040 The details are now on our site. Hopefully they're suitable prices. 🤞

[@DrBenVincent]

So how does the body’s circulatory system manage to push blood around TONS of vessels with just heart beats? Feels like there’s some more gains on the table which could be had from learning from biology?

[@jimmiedow]

Are there any cylinder brands available in the U.S.A. which have a similar design?

[@metalhead2550]

From looking at the open energy monitor dashboard the minimum cop for DHW was in February at 3.82 and maximum was in December(?!) at 4.90 with an overall cop Jun - Apr of 4.54

[@HeatGeek]

We got over 5 a number of times

[@metalhead2550]

@@HeatGeek I'm sure, I was looking at monthly snapshots :)

[@HeatGeek]

@@metalhead2550 great insight. Thanks!

[@Carpe-Diem]

This is all great, and admiral to drive standards up, but I live in Portugal! 😅 (PS just about to have a heat pump and UFH installed, but here you can’t influence the tradesperson!)

[@jmb69er]

Many cylinders boast smooth internal coils.. you now have gone back to ribbed coil... Wont there be an issue with potential lime scale build up on the coil now? Which will quickly reduce heat transfer as it builds up

[@HeatGeek]

Ribbing doesn’t affect scale build up. Only concentration,ph and temperature

[@stephenhall1774]

Because of the high cost of most dwellings and therefore lack of space, the most exciting solution of all would be a cheap efficient heat battery, like a cheap Sunamp. Much smaller and no issues with legionnella.

[@PeterJFlower]

The most common problem I've seen is the water taking a long time to heat up. Priority hot water means that the heating can't run whilst heating the hot water. Hopefully the look at controls will address this.

[@HeatGeek]

Quite a simple solution to that. Set the hot water to come on earlier to compensate. Out of the thousands of hot water priority homes over worked on I’ve never had an issue with the home temp dropping during hot water heating.

[@MrSteven3110]

Hi I have built a new house with an air source heat pump solar panels 3 phase battery and solar thermal problem is I’m a bit confused about settings for hot water initially i was told to just put in temperatures on thermostats and leave it to run but I’ve changed to octopus go as I’ve an electric car coming tomorrow so not sure this is the right strategy. I have brand new 350l hot water tank which is tall and thin should I be heating this only when cheap octopus overnight tariff is on or leave it continuously on ?

[@dmitryplatonov]

I would do 2 tanks and put in series - bigger run on the cheap energy only, smaller always.

[@therealcaldini]

Can you make me a ‘cylinder’ that’s the same size and shape as a combi boiler because I haven’t got room for anything else

[@spankeyfish]

You can reduce the legionella risk and minimise stirring the tank with a tank that uses a coil for DHW so you aren't drinking the water that's in the tank. The one I'm pondering has the radiators and heatpump/boiler connected to the water in the tank (with baffled inlets) and a coil at the bottom for solar thermal.

[@malcolm8564]

Why would you be drinking the tank water? Your drinking water comes straight from the mains.

[@annedreikandt7361]

@HeatGeek How does it compare to the Vaillant uniSTOR? Especially in conjunction with a Vaillant arotherm plus heat pump? Thanks in advance ❤

[@HeatGeek]

It’s heat around 30% more efficiently

[@michaeljames3907]

I don't really have storage outside, but do in the garage. Is it possible to have a heat pump in the garage, with low noise, given there is a room above?

[@HeatGeek]

No its needs fresh air with heat energy in it

[@MarbewRecords]

What is the italian name for thermal store? Do you believe Italians know about it?

[@davecavaghan7889]

how do you change an indirect open vented cylinders coil size or do the things you have advised without actually changing the cylinder?

[@HeatGeek]

Controls. See part two due next week.

[@GarethColeman_UK]

Hi i'm trying to educate myself - i live in a narrow terrace house built in the 60's which we've upgraded the insulation and glazing on. Now we are looking at the heating/ hot water. We're currently set up with a vented cylinder, oversized rads. But we don't have a great mains flow rate. Is the cylinder from newark available in a vented form, or does that change things completely?

[@barryprice9526]

I Googled "Can i vent an unvented hot water cylinder" This is from Bishop plumbing Can I Use An Unvented Cylinder In A Vented System? Yes! You may want to use an unvented cylinder in a vented system if it has come time to replace your vented hot water cylinder, and you would like to convert your home to an unvented system one day but do not currently have the means. This way, you can avoid having to replace your new cylinder prematurely when you are ready to convert, as well as spread out the cost of the conversion.

[@CommercialGasEngineerVideos]

Well edited vid

[@paki20]

So for an example, say I spend £1 day to heat a hot water cylinder with an immersion on constantly with stat to control max temperature, can I bring the cost down to 20p with this technique?

[@HeatGeek]

If you used that little hot water, yes, Correct

[@Y-oldfaithful]

Really interesting video. But with a big DHW tank there must also be a bigger overall heat loss. There must be a way to calculate where that sweet spot is, right? Otherwise a 500L tank would be even better 😎

[@HeatGeek]

Yes but heat loss is very small. Especially at low store temps

[@lexxynubbers]

What is the maximum theoretical COP? There is presumably a maximum amount of heat that can be moved against a given gradient. Could you have another measure of efficiency as the % of this maximum?

[@mountsorrelheritage]

From engineering toolbox:- COPheating = Th / (Th - Tc) COPheating = Coefficient of Performance - heating process Th = absolute temperature on the hot side (K) Tc = absolute temperature on the cold side (K)

[@jedherman7450]

I have the Vailant one…only went in 6w ago 😢. Adam, I have OEM - how do you get it to identify the data as DHW - thanks.

[@HeatGeek]

I have a separate meter for dhw

[@apoulterhhi]

For the 300 litre tank that they sell, what would you recommend for a dedicated heat pump for the cylinder?

[@HeatGeek]

Vailant arotherm

[@normanboyes4983]

I think Adam misunderstood the question. You would not need a dedicated heat pump for a 300Litre domestic hot water cylinder. The heat that provides the heat into the home operates on a ‘priority domestic hot water’ basis.

[@apoulterhhi]

I have owned air to air systems in the past and was very satisfied with them. They don’t work with hot water. Update . There are some that now heat water too

[@pmbpmb5416]

So my installer is suggesting a joule 400 litre eco 80 tank which seems to fulfill the volume , tall and slim requirements. Should I be asking them to look at the Newark for further advantages ?

[@HeatGeek]

If you want the most efficient cylinder, yea

[@LeiChat]

@@HeatGeek Does part 2 provide an insight on how much better the HG Newark cylinders are, please? From what was being debated in a thread on Open Energy Monitor forum, I did find myself thinking the benefit wasn't something you would do for a ROI, unless you use a large volume of hot water and are not able to take advantage of off-peak tariffs.

[@HeatGeek]

@@LeiChat well my cylinder is 4.6 scop. Will save just over £100 per year over a 2.5 scop for a 2000kwh demand. 10 years will save £1000, which will justify expense over a poor cylinder. A vailant cylinder will be around 3.5 scop but cost around the same as this Newark so o think works out just fine right?

[@LeiChat]

@@HeatGeek Sounds good, thank you. We have had a Newark with 4m2 coil since February and the scop to date is 3.6. Looks like our annual DHW demand will be around 1000kWh. In the 48 days prior to the Newark being installed the DHW scop on our old cylinder with a 0.8 m2 coil was 2.95

[@zakthetech]

Surely if replacing the whole heating system and wanting to reduce the wastage and co2 we should also mention WWHR as that would allow for the use of less hot water. Surely it is better to use less (and make what you do use more efficient). Ultimately with an ASHP you are usually talking about major upheaval anyways and while this would likely add soke cost the minimal maintenance and reduced costs should be recouped fairly quickly.

[@ricos1497]

Maybe you should mention what WWHR stands for! I'm going to guess that the WW doesn't stand for world war, as that's already trademarked, but maybe waste water?

[@zakthetech]

@@ricos1497 WWHR IS Waste Water Heat Recovery. If you have a shower then the waste hot water is sent out down the plug then down a copper column and the incoming cold water supply for the shower and hot water tank runs up the outside in Separate copper pipes, pre heating the incoming water with the heat from the waste water. This means when you mix the hot and now slightly warm water you use less hot water thus saving more money. Look up power pipe R4-84 for a good example of this.

[@johnzach2057]

There are some heat pumps that can produce DHW on demand. Will these be more efficient?

[@ImprobableWizard]

There is an interesting heat pump that was designed by a car manufacturer in Japan ages ago call the Eco Cute. It runs on CO2 so no problems with global warming. They are starting to appear on the continent but very difficult to get any information even though the idea has been around since the early 2000s. There is a relatively lightweight outdoor unit of 45kg and it generates water at 60c+ so it can be used as a direct replacement for a gas boiler for heating. Not sure about for hot water. The main idea is that it would be a direct replacement for gas as it doesn't require upgrading radiators.

[@johnzach2057]

@@ImprobableWizard CO2 HPs don't have better cops than R32 HPs

[@howyanow4810]

Do you partner with anyone in Ireland?

[@Macro_Abuser]

Stratification makes sense. I noticed my tea is always cooler the more i drink. Someone should make a mug shaped like a gravy fat strainer

[@davidtones4917]

So this it the cylinder octopus are going to install at my property Daikin Hot Water Cylinder 180L (EKHWSU180D3V3) what are your thoughts?

[@HeatGeek]

Not a patch

[@davidtones4917]

@@HeatGeek is that good or bad lol 😝

[@sean4526]

Wow where?

[@andypower6938]

Top man

[@kubastachu9860]

If only water heater manufacturers hired a few engineers who'd be willing to just make a few calculations based on physics, we wouldn't have to do it ourselves...

[@adamsweet3587]

The cost of these tanks are quite high compared to the likes of Joule tanks, and if the tank is unvented, you need a G3 qualified installer. Love the efficiency of all of this, but the price needs to come down.

[@imnothere220]

Anyone got experience using this with a NIBE? Maybe an 1156?

[@eco-terrorist]

i have a buffer from ADVANCE APPLIANCES LTD ADVANCE SFUTS 300L MULTI-FUEL THERMAL STORE HEAT EXCHANGER HOT WATER 35KW HEAT EXCHANGER SOLAR 17KW SOLAR COIL OUTPUT 20KW (0.75m2) HOT WATER COIL OUTPUT 35KW (1.5m2) one shower seems to remove 5 degrees of heat from the top of the cylinder the solar coil will be used for the ASHP flow & Return (the buffer tank feeding two towel rails one 12m2 office and the DHW) with the Gas now removed (GAS boiler finally gave up in feb) i use immersion heating using either Solar or Cheap Night Rate the 7.5p for 6hrs if there is no sun the night rate is as follows raise the temp from 40 - 70 takes 10.50Kwh of power about 75pence per night and a time at 6kw of 1hr 45m Until Oct the sun will charge the immersions, i hope my planning gets approved before this winter season Part 2 ‘Controls’ - coming soon!.. 👍👍

[@HeatGeek]

Next week

[@robynrox]

Why are we not using solar hot water capture with another system (perhaps a heat pump) as a backup? As efficiency goes, that would surely be the most efficient approach when the sun is shining?

[@robinbennett5994]

because solar electricity has a better ROI and is more flexible. * most people spend a lot more on electricity than heating water, so the potential savings are larger. * Water heating systems have to be quite complex in the UK to avoid freezing. * It's cheaper to run a wire out to your roof than pipes (full of anti-freeze) * When you have excess electricity you can get paid to export it. * If you use solar electricity to run a heat pump, the efficiencies are similar.

[@robynrox]

I do wonder if, with the right design, components and thought put into a system, the ROI might work the other way. It seems to me that a system could be designed such that it does not pump water through a solar collector on low temperature days, mitigating the need for anti-freeze. A system could be mounted at ground level - perhaps less efficient than on the roof, but with a bit more surface area, still the same amount of energy could be collected, and maintenance of such a system would then be easier. (Shade might be more of an issue.) I think ROI is generally extremely questionable with the type of heat pumps marketed to us for use in UK homes, though the government grant helps immensely towards that. And if you had the option of buying a heat pump and a certain number of solar panels vs basic resistive immersion heating along with more solar panels (spending the same amount of money), the heating might be less efficient but you'd be producing more electricity and might have the capacity to export more (though I'm aware that there are limits to the amount you can export through having a solar power system myself), so that could be another option.

[@robinbennett5994]

@@robynrox That sounds like you're thinking of using solar for heating, not just hot water? The problem there is that we just don't get enough sun in the winter.

[@robynrox]

I was just thinking of hot water but I went off on a tangent. I'll leave it there, anyway, as I'm not planning on changing my existing system right now. Thanks!

[@normanboyes4983]

@@robynroxMaybe build that very system and report back.👍

[@AlwaysStaringSkyward]

This couldn't be any more timely as we try to figure out how to stop choking on LPG bills!

[@oscargoldman85]

OK... Heres a idea that should (also) revolutionise the industry; Why can I not use the heat from the back of my refrigerator to heat the water in my hot water cylinder. Why are they both not next to each other as standard in all homes with a heat exchanger between them?

[@mountsorrelheritage]

Where does that heat come from? Your kitchen.

[@oscargoldman85]

@@mountsorrelheritage Refrigerators are based on heat exchange, the compressed gas is put into low pressure inside the Fridge, absorbing heat from the fridge to assume the gaseous state, then out the back, the gas is compressed again, releasing that heat. Thats why the radiator on the back of your Fridge is warm, the colder it is inside the fridge, the more heat is released out the back.. this heat usually heats up the kitchen a little bit, but not much, it seems a pity to waste that heat, it could be used for the hot water cylinder.

[@mountsorrelheritage]

@@oscargoldman85 Start with some data and assumptions Daily hot water energy requirement ~ 5 kWh to 7 kWh (from Heat geek heat pump monitor data) Daily Fridge/freezer energy consumption ~ 0.8 kWh (ours is quite old now so this a bit on the high side). Fridge/freezer COP ~ 2.5 to 2.1 (assume 2.5) COP = (Q + W) / W (where Q = heat transferred, W = work to transfer the heat or the power in) Or Q = (COP - 1) * W (The heat pump uses energy to move heat from one location to another.) Heat leaks into the fridge from the kitchen. The refrigeration unit then pumps this heat back out to the radiator at the back. Heat moved from the fridge back to ambient (radiator) (COP - 1) * W = 1.5 * 0.8 = 1.2 kWh Heat deposited in the radiator is therefore this PLUS the energy used to move the heat 1.2 kWh + 0.8 kWh = 2.0 kWh (Confirm this matches our COP = (1.2 + 0.8) / 0.8 = 2.5) So in summary 1.2 kWh leaks into the fridge from the kitchen. This 1.2 kWh is pumped out by the refrigeration unit to the radiator at the rear, PLUS the 0.8 kWh required to do the pumping, and this is returned to the kitchen. On balance the kitchen is heated by 0.8 kWh. If the heat in the rear radiator is now used elsewhere the kitchen loses the 0.8 kWh from the compressor AND the 1.2 kWh that is leaking into the fridge from the kitchen. So we will now need to heat the kitchen to make up this 1.2 (2.0) kWh shortfall. So basically you are recovering the compressor power BUT increasing the demand on the heating. You might be making savings since the radiator is cooler so the fridge may be more efficient. You are balancing the COP of the heat pump against the COP of the refrigerator. As fridge/freezers get more efficient (better insulation and higher COP) then any gains get less. Other things to consider. The fridge is unlikely to be operating when you need to heat the water. Pumping heat into the cylinder when it is not needed will probably just add to the standing losses (modern cylinders have losses around 60 W, 1.4 kWh per day). And finally, well done for considering ways to make use of "lost" heat. It made me think.

[@Geyer128]

I see what my heatpump company did right. (Big hot water tank)

[@RedBatteryHead]

Mixergyyyyyyy 👍

[@justatiger6268]

70 degrees C at 300% efficiency? That... sounds almost impossible. How?

[@HeatGeek]

R290.. from cold.. follow the link it’s real

[@olninyo]

I wish we had installed a larger cylinder for the overnight tariff/excess solar reasons. ah well.

[@jasonallatt5410]

I am just going to re-design and improve my existing heat pump. 😂

[@mgbroadsterJ]

Priority hot water should e the standard .