What energy rating is your HW cylinder?

[SteamyTea]

11 minutes ago, Marvin said:

and you'll definetly save money in the long run.

I did from my big standard 1987 era E7 200lt cylinder.

About 20p a day when heated to 65⁰C.

Lot less now it is at 45⁰Cish, and I use most of it just after it has reached max T.

[Radian]

1 hour ago, Marvin said:

If I have it right,  this type of immersion heater thermostat relies on a bimetallic switch which relies on a typical room temperature to work:

 

I don't think so. The bimetallic action is a mechanical movement resulting from differential expansion of two dissimilar metals bonded together. A bit like how a plank of wood will curl up when only one side gets wet. Both metals are subject to the same temperature.

 

However, the kind of probe shown in your photo looks more like a bulb and capillary thermostat. These have a bulb in which a fluid expands in response to temperature and operates a diaphragm switch via the capillary tube. 

[Adsibob]

Thanks @Marvin, that's helpful.

1 hour ago, Marvin said:

yours sounds more complicated. what is it?

Mine is a Telford Tempest Indirect Unvented 300L. Bought from cylinders2go at @Nickfromwales's recommendation.

I now wish I'd researched this more and bought something with more insulation already on it, as a C rating just doesn't sound very good.

I think it is pretty straightforward, it just has an immersion heater and a secondary loop with a pump attached to the secondary loop.

I also need to insulate all the copper pipes going in and out of it. Any good recommendations for 22mm and 15mm pipe insulation?

[PeterW]

21 minutes ago, Adsibob said:

I now wish I'd researched this more and bought something with more insulation already on it, as a C rating just doesn't sound very good.

Have you looked at the difference between a C and an A rated cylinder in terms of losses ..?? Most older cylinders are G rated - that’s the ones from pre-2010 which tbh had 40-50mm of insulation on them. The ErP changes introduced in 2017 gave the manufacturers the standards to work to but it’s less than the losses from uninsulated pipework by a long way.  

You also have to compare like to like - a 90 litre tank has an easier time getting an A than a 300 litre tank due to surface area. In reality, the difference between A and C is around 21w loss per hour at 68°C constant on £300 litres so about £50 on direct electric or £33 on gas. The cost differential between an A and a C tank is around £400, so 14 year payback. £400 buys a lot of pipe insulation wifi will have much more impact on heat loss than any A rated tank. 

 

[Adsibob]

18 minutes ago, PeterW said:

Have you looked at the difference between a C and an A rated cylinder in terms of losses ..?? Most older cylinders are G rated - that’s the ones from pre-2010 which tbh had 40-50mm of insulation on them. The ErP changes introduced in 2017 gave the manufacturers the standards to work to but it’s less than the losses from uninsulated pipework by a long way.  

You also have to compare like to like - a 90 litre tank has an easier time getting an A than a 300 litre tank due to surface area. In reality, the difference between A and C is around 21w loss per hour at 68°C constant on £300 litres so about £50 on direct electric or £33 on gas. The cost differential between an A and a C tank is around £400, so 14 year payback. £400 buys a lot of pipe insulation wifi will have much more impact on heat loss than any A rated tank. 

 

Yes, you're right that obsessing about getting an A rated tank doesn't make sense. 

Rather annoyed with my builder and his plumber for not doing a better job on insulating pipes though. The secondary loop and the hot water pipes (both buteline) were insulated before the walls/ceilings were closed up, but only with a thin sheath of insulation, i think made of foam. The copper pipes which are exposed coming out of the cylinder and coming out of the boiler are NOT insulated at all.

This hasn't been picked up by the BCO which is surprising given that the regs appear to suggest insulating pipes with specific thicknesses of insulation is mandatory. I don't live in Tameside, but see page 5 of this: https://www.tameside.gov.uk/buildingcontrol/guidancenotes/note24guide5.pdf

I haven't paid the retention on my install yet, so am considering withholding it until this is rectified. Although not sure it will be possible to rectify the actual pipes which are inbedded in the walls, though maybe I'll overlook those given the heat loss shouldn't be too much through buteline covered in thin foam insulation and given the heatloss is still within the thermal envelope of the house. But not insulating the exposed copper seems negligent.

[PeterW]

2 minutes ago, Adsibob said:

The copper pipes which are exposed coming out of the cylinder and coming out of the boiler are NOT insulated at all.

Not only building control but part of the Manufacturers Instructions for installation that all pipe work is insulated.   

[SteamyTea]

31 minutes ago, PeterW said:

difference between A and C is around 21w loss per hour at 68°C

That will be 0.021 Wh then.

0.5 kWh a day. So somewhere between 3.5p and 17p per day.

Or £13 to £62 a year.

[Marvin]

2 hours ago, Radian said:

I don't think so. The bimetallic action is a mechanical movement resulting from differential expansion of two dissimilar metals bonded together. A bit like how a plank of wood will curl up when only one side gets wet. Both metals are subject to the same temperature.

 

However, the kind of probe shown in your photo looks more like a bulb and capillary thermostat. These have a bulb in which a fluid expands in response to temperature and operates a diaphragm switch via the capillary tube. 

Hi @Radian , your quite right, meant the other ones...

[Marvin]

2 hours ago, Adsibob said:

Any good recommendations for 22mm and 15mm pipe insulation?

If the pipework is not subject to very high temperatures and not external, for me, climaflex was the best option.

 

I bought it as thick as I could get on the pipes for any hot  pipes.  I set my pipes away from the wall to allow for this.Cuts easily with a hacksaw. Mitre the corners. Don't leave any gaps.

 

It will shrink a bit over time so buy spare. Mine went about 10mm a metre.

 

I used 25mm wall thickness on my 28mm pipe.

 

 

This thickness is not cheap.....

[markocosic]

The best insulation will be Phenolic. Kingspan Kooltherm etc.

 

Available up to 40 mm thickness but much beyond 25 mm is rapidly diminishing returns for smaller pipework.

 

Don't use it on anything much above 60C. It will turn to dust in time in spite of what the manufacturer (with Grenfell morals / ethics) claims. 

 

Tape all joints to stop air movement. Plastic clips spaced off the wall as Marvin has done.

 

Failing that class o armacell (as used on cooling systems) tends to better job than climaflex mostly thanks to being designed to be taped/sealed properly. Stretches between glued joints father than shrinks.

 

Expanding foam also works for chuffing awkward bits that you care not to touch again...and fibreglass / mineral wool stuffed generously into awkward boxed sections.

[Spacey73]

In reply as to why I’m going Sunamp route for water. I can’t drill for oil or gas but I can harness the sun no issue.

 

currently now have 9 x 450w panels dedicated to its own 9Kwh battery pack to charge the Tesla. Panels are south facing but at a slight pitch due to workshop tin roof, but reform surprisingly well on cloudy days. They also perform nicely at all angles from morning to evening sacrificing peak mid day performance for a more balanced all day output and better cloudy day output.

 

For the house I have 12 x 390 watt panels in series on one MPPT and 10 x 320 watt panels in series on the other independent mppt input.

 

these panels are facing South in a 3acre field with no shadows, I can also adjust them as the season changes. Battery storage for the house is now 2 x 17Kwh Lifepo4.

 

My reason for getting Sunamp is that I hate radiators as they take up too much room and the piping is just ugly and annoying

 

so we’ve just had installed 1 x 7kw heat pump to air conditioner for main front room and then a multi split in the 4 bedrooms 2.5kw each conditioner.

 

I’m probably going to get another 12 x 390W panels and dedicate them to the Air Conditioning. Air Conditioning will be run on its own off grid 8Kw inverter and share the 2 x 17Kwh batteries with house.

 

Will be adding dormers upstairs in Bungalow hence bigger Sunamp, boiler, most copper pipes and radiators will be gone as will the oil storage.

 

so far we still have 600 litres of oil In trying to use up but the house has been pretty much off grid all month with only half the panels wired up ….work in progress 

Edited September 20, 2022 by Spacey73

[PeterW]

2 hours ago, Spacey73 said:

My reason for getting Sunamp is that I hate radiators as they take up too much room and the piping is just ugly and annoying

Sunamp doesn’t do central heating ..? It’s DHW ..?? And not a good volume at that. In your case I would chuck the biggest direct UVC in I could find with 3 immersions on it and use as a pure dump load from the solar in the summer, and it could be phased in winter depending on the DHW required, so heat in thirds. A direct 500 litre is £1200 and can be fitted by any decent G3 plumber and can be over charged up to 85-90°C with no issues. The same capacity in Sunamp would cost you £6k plus the space needed would be more - why spend the money ..?

[JohnMo]

3 hours ago, Spacey73 said:

My reason for getting Sunamp is that I hate radiators as they take up too much room and the piping is just ugly and annoying

So you have loads of solar, and Aircon for cooling and heat.  Why is this a reason to have a sunamp?  No logic to join the decision process.

 

3 hours ago, Spacey73 said:

Will be adding dormers upstairs in Bungalow hence bigger Sunamp

Again no joined up logic, what has a hot water storage got to do with dormers.

 

If you want a sunamp, just say you want a sunamp.  Nothing to do with anyone else.  Your money your choice, wouldn't be my choice, but it's your money.

[Nickfromwales]

On 28/07/2022 at 14:42, Adsibob said:

Mine is a Telford Tempest Indirect Unvented 300L. Bought from cylinders2go at @Nickfromwales's recommendation.

I now wish I'd researched this more and bought something with more insulation already on it, as a C rating just doesn't sound very good.

Sorry, I seem to have missed this. 
Clients with these installed ( in PH settings ) have reported sub 1oC/hr losses from the Telford cylinders. 
Back in the day I commissioned Telford to make me a “super-cylinder”, with 100mm of spray foam applied. Turns out on paper it had worse credentials than the 50mm of standard injected foam. Go figure  

Pay 3x the price for a slightly better performing unit, and then sit down and work out how many times you’ll have to live to receive the benefit.

Manufacturers state wonderful facts and figures, but few state that they’ve not allowed for losses from the unavoidable connected pipework etc.

Sub 1oC/hr losses will satisfy most. 
 

Back to my cheesecake now. Tonight it’s vanilla with some strawberries and cream. At least I’ll die happy 😆 

[Nickfromwales]

14 minutes ago, JohnMo said:

So you have loads of solar, and Aircon for cooling and heat.  Why is this a reason to have a sunamp?  No logic to join the decision process.

 

Again no joined up logic, what has a hot water storage got to do with dormers.

 

If you want a sunamp, just say you want a sunamp.  Nothing to do with anyone else.  Your money your choice, wouldn't be my choice, but it's your money.

Yup. Huge, huge expense, zero benefit. 

[Nickfromwales]

3 hours ago, Spacey73 said:

In reply as to why I’m going Sunamp route for water. I can’t drill for oil or gas but I can harness the sun no issue.

Same harnessed energy goes into the same principal; eg heating hot water by means of an immersion, via direct electricity or excess diversion, from micro generation.

Doesn’t require a Sunamp at all, just means that they will do the same job, but at 3-4x the price of an UVC and with a number of caveats.
 

Add in an inherent and massive uplift in ‘specialised’ installation and ‘niche’ product cost and any money / savings you stand to benefit from, via the stated energy efficiency, are only going to be for the next generation to benefit from.
 

That’s if it then lasts long enough, bearing in mind it does not attract a lifetime warranty like the Telford stainless cylinders do  

 

Time to look realistically at a product which will likely never pay for itself in its lifetime, and think again. Unless you’ve money to burn of course. 

[SteamyTea]

1 hour ago, Nickfromwales said:

Back to my cheesecake now. Tonight it’s vanilla with some strawberries and cream. At least I’ll die happy

I had a cheesecake the other day, mixed chopped up raw finger chillies, then a few grapes and some caramel sauce.

I was happy, and I did not die.

[Adsibob]

7 minutes ago, SteamyTea said:

I had a cheesecake the other day, mixed chopped up raw finger chillies, then a few grapes and some caramel sauce.

I was happy, and I did not die.

Do you need any help?

[Iceverge]

Larger cylinder = Lower losses. 

 

We have a 300l cylinder which gets heated to 70deg by overnight electricity.  Storing approx 14kWh of juice. It looses an average of 68w over 24hrs. 

 

If we had a 500l cylinder we could drop the storage temp to 57 deg for 14kWh. 

 

Although there is more surface area to loose heat it is more than compensated by the lower delta T to the room temp as it's standing losses are only 30w for the same amount of insulation. 

 

 

 

[SteamyTea]

29 minutes ago, Adsibob said:

Do you need any help?

No, bought it all, mixed it all, ate it all.

Not often I have a day off, but made a new dish to sell.

[joe90]

I too have a Telford cylinder and the losses are minimal, Sunamp is too new a technology for me and expensive. Also the losses are not losses in the winter as they stay within the house 🤷‍♂️

[SteamyTea]

Shown this before.

This is the temperatures logged on my E7 cylinder last year.  The mean temperature differences (top of tank) are 4°C, but if taking just the times minimal water is drawn off (10AM to 1 AM next day), the standing losses is 3°C over 15 hours, that is 0.2°/hour.

There is nothing special about my installation other than the cupboard it is kept in is stuffed full of insulation and I limit the charging times to 3 hours.

 

So, I would not be happy with that sort of unnecessary losses.

11 hours ago, Nickfromwales said:

Clients with these installed ( in PH settings ) have reported sub 1oC/hr losses from the Telford cylinders. 

 

[Spacey73]

15 hours ago, PeterW said:

Sunamp doesn’t do central heating ..? It’s DHW ..?? And not a good volume at that. In your case I would chuck the biggest direct UVC in I could find with 3 immersions on it and use as a pure dump load from the solar in the summer, and it could be phased in winter depending on the DHW required, so heat in thirds. A direct 500 litre is £1200 and can be fitted by any decent G3 plumber and can be over charged up to 85-90°C with no issues. The same capacity in Sunamp would cost you £6k plus the space needed would be more - why spend the money ..?

I never said it does do central heating? I said I don’t like radiators or oil …so when I get rid of the radiators and instal 2 x Heatpumps and 5 air conditioners….I’m going to need something  heat the water. Maybe something half the size and doesn’t lose energy so quick. Hence Sunamp.

 

you can actually use them for central heating but I don’t see many benefits for that. 
 

Didn’t cost £6k more like £4.5k all installed, plus I’ll be scrapping all that lovely copper piping.

Edited September 21, 2022 by Spacey73

[PeterW]

6 hours ago, Spacey73 said:

Maybe something half the size and doesn’t lose energy so quick. Hence Sunamp.

 

you can actually use them for central heating but I don’t see many benefits for that. 
 

Didn’t cost £6k more like £4.5k all installed, plus I’ll be scrapping all that lovely copper piping.

Have you seen one in the flesh ..? Or actually read anything other than the sales pitch ..? Real world experience says that they aren’t all they are cracked up to be - and your £4.5k is for the equivalent storage of a 170 litre hot tank - not the the 500 litre I quoted. Its your money but it’s a one trick pony and it doesn’t do it that well either .. 

[ProDave]

The SA sounded like a good idea mainly because of it's lower heat losses, but the fact you can't heat it from an ASHP and the fact that if the heating element does fail (not unknown) you can't just drain it and replace with a standard immersion heater like you can any other hot water tank are what put me off.