Unvented/pressurised cylinder

[Sunshine12]

Any brands/recommendations on an unvented cylinder?

Been looking at Heatrae Sadia 'Eco Plus'

£1400 for 300l
Then jumps up to £1900 for 400l/£1950 for 500l

Also seen an everflo £1380 for 400l

Not sure if much difference between the standard and eco plus? Any other recommendations?

Not sure what size cyclinder to go with either. Plan to have 3 bathrooms all with rainfall shower heads & jets.

Just 2 of us at the moment and little ones who will obviously grow into teenagers!

We spend about 15-20mins in the shower each per day, kids have a shared bath. Will have a dishwasher so hope not much washing up.

Would you spend the extra and upgrade to a 400 or 500l now to safeguard for future or is that really excessive?

Thanks in advance

 

[WLF85]

I would say your suggestions are all massively oversized

 

[muggles]

300L should be loads - don't forget it's 300L at 60ºC, which is about 450L at a usable showering temperature. Reheat times are about 25 mins on a 300L cylinder, so provided your boiler is firing to heat the cylinder while you're showering there shouldn't be a problem with capacity

 

[Roger928]

I would say your suggestions are all massively oversized

I would have said that too but this guy is obviously a water and energy waster spending 20 minutes in a shower and encouraging the rest of the family to do the same..

 

[muggles]

Presumably isn't on a water meter! Current AD:G requirements for new builds are for 125 litres per person per day total water usage - looks like he's intending to use twice that on his showers alone!

 

[Sunshine12]

I'm actually a female!!! Yes we have a 15-20 min shower per day, wow hardly a big deal, yes we have a water meter which we pay our bills for.

The question was which cylinder and capacity not getting into a discussion about water wastage.

So if we have a 300L how long is that going to last after shower & kids bath?

 

[WLF85]

I have a 6-bed 3-bathroom + 1 WC house and I have a 210l unvented cylinder.

We never run out of hot water.

You may well need a bigger cylinder, but I just can't imagine a 400l cylinder being efficient for you.

 

[Sunshine12]

Thanks WJF that's good to hear! Seems that a 300l would definitely be enough then! Or maybe a 250.

Any particular brands to go for/avoid?

Any reviews on the heatrae sadia megaflo?

 

[fezster]

We have a 250L megaflo and personally wish I'd gone for slightly bigger to future proof as the kids get older. We also have rain type shower heads delivering around 20l/min each. Assuming 50/50 split of hot and cold, that's 25 mins total showering time. Fine for 2-3 people, and probably more if not being used by more than 2 simultaneously, as they are quick recovery cylinders, so you can heat up the water as it's being used. I think a 300l would be ok, more if being used simultaneously by >2 adults.

I'm not very impressed with Heatrae Sadia. Have a read of my past posts, but in summary, the 22mm pressure reducing valve they supply is inadequate for high flow rates (>40l/min). Heatrae Sadia did not really want to know, simply quoting that the cylinder was good for over 80l/min in lab conditions. We ended up upgrading our pipework to 28mm and having a commercial 28mm pressure reducing valve fitted. Having a quick look, I think the Eco Plus models use 28mm as standard, which may resolve this problem.

The other thing to consider is that using the same manufacturer boiler/cylinder makes integration better. For example, we have a Vaillant boiler, which when paired with a Unistor cylinder allows you to run your heating at a low(er) temperature, and the boiler will automatically increase to 80 degrees for heating the cylinder. Without this integration, the boiler temperature for your heating is dictated by your hot water cylinder requirement, which means unnecessarily toasty radiators in the summer.

 

[Agile]

When sizing a cylinder you need to look at the number of PEOPLE and not bedrooms/bathrooms.

The usual rule of thumb is 50 li plus 50 li per person. So FOUR people would be 250 li.

But that is based on the typical shower using about 10 li/minute.

If you must waste water on rainfall showers then you should double the recommendations. That's 100 litres plus 100 litres storage per person!

But 20 minutes at just 10 li/min will be 200 litres of stored water usage. Your rain shower at 20 li/min will take 400 litres.

So with TWO people you could be using 800 litres of hot water.

True there may be some reheating during your showering, and storage at 60 C and usage at 43 C will also give a small advantage.

You will presumably have at least a 32 mm water supply into the house to accommodate all this water flow.



Congratulations on being a female. I often take them out for dinner with a nice bottle of wine!

Tony

 

[Sunshine12]

Yes have 32mm mdpe pipe from stop tap.

Why are some people saying 300l is far too excessive now others saying we need more?

 

[Agile]

Many people find it hard to accept that there are some like you who want, and can afford, to be profligate with hot water usage.

I like to use a smaller older car. It is only transport and easier to park and if it got scratched at Tesco then not a big problem.

But outside the schools there are mothers queued up in massive new 4x4s to collect their little brats who could easily walk home or use the bus!

I like to think that I understand the world better!

Tony

 

[WLF85]

Agile your maths is fantastic.

Perhaps you could show us all exactly how much of the 10 litres per minute is hot water from the cylinder and calculate the reheat times.

Then perhaps you can buy us all a bottle of wine, not just the women you sexist so-and-so.

 

[Roger928]

If Agile spent less time getting his dates inebriated on cheap wine he would know the mix ratio equation and tell us exactly the flow rate required from the cylinder and the flowrate required from the cold when the shower delivers 12l/min @38c.
Then perhaps the OP will buy him a bottle of wine.

 

[PullerGas]

Very little to do with the capacity of the cylinder, more to do with the cylinder coil & recovery times.

20 minutes in the shower you're having a laff luv??!!
I have a Navy shower every morning, in & out in 5 minutes.