Unvented Cylinders

[rmwilford]

I have some questions on unvented storage cylinders.

1. Is a particular make more thermally efficient that the others? ie less heat loss
2. Is a particular make more "intelligent" that the others? ie links to/talks to the rest of the system to operate more efficiently
3. Are there problems with installing the tank in the loft - ie tank bursting and scalding inhabitants below

....and to change tack slightly....

4. I have a 4 bedroom, 1 bathroom (big bath and shower), 1 ensuite (shower only) house with decent mains pressure - would a Vaillant EcoTec 937 be a cheaper system to install (I believe so) and run (I don't know) than an unvented/storage system. Cost of installation and fuel bills are an important factor to me.

 

[Nixt]

Cost of installation and fuel bills are an important factor to me.

Therin lies your dilemma. Deciding which of them is the more important factor, may help you obtain a more accurate answer.

 

[rmwilford]

Cost of installation and fuel bills are an important factor to me.

Therin lies your dilemma. Deciding which of them is the more important factor, may help you obtain a more accurate answer.

Ah. So to clarify, I'd be more than happy with a larger outlay if it saved fuel bills in the long term. I just get the feeling that heating-on-demand (a-la EcoTec 937) will be more efficient than storage....but I don't KNOW that - it's just a gut feeling.

 

[Nixt]

In that case stored water (more so with thermal stores) enables better compatibility with renewable technology (eg solar) should you wish to go that route at a later date.

 

[rmwilford]

Thanks Nixt. I did mention Solar on a previous thread I started on the EcoTec 937. Solar won't link to it as you allude to but another seasoned poster said they couldn't understand the obsession with solar as it was totally un-viable from a financial sense (at the moment). I know it will become more viable and it's a tough call as to whether to plan for it or not.

I have some questions on unvented storage cylinders.

1. Is a particular make more thermally efficient that the others? ie less heat loss
2. Is a particular make more "intelligent" that the others? ie links to/talks to the rest of the system to operate more efficiently
3. Are there problems with installing the tank in the loft - ie tank bursting and scalding inhabitants below

can anyone offer guidance on points 1 to 3 please?

 

[Nixt]

1. Is a particular make more thermally efficient that the others? ie less heat loss
2. Is a particular make more "intelligent" that the others? ie links to/talks to the rest of the system to operate more efficiently
3. Are there problems with installing the tank in the loft - ie tank bursting and scalding inhabitants below

[/quote]

1= Not to my knowledge amongst the major makes, though avoid Ariston.
2= Again no, they are generally a vessel. I prefer my own external controls anyway.
3= No problem if installed correctly and weight adequately supported, although there's always some risk however small.

As for solar. I did say 'should you' not 'you must'. Meaning you could invest in a vessel that has the necessary spare coil which will not cost much more than standard versions.

 

[BigBurner]

Thanks Nixt. I did mention Solar on a previous thread I started on the EcoTec 937. Solar won't link to it as you allude to but another seasoned poster said they couldn't understand the obsession with solar as it was totally un-viable from a financial sense (at the moment). I know it will become more viable and it's a tough call as to whether to plan for it or not.

I have some questions on unvented storage cylinders.

1. Is a particular make more thermally efficient that the others? ie less heat loss
2. Is a particular make more "intelligent" that the others? ie links to/talks to the rest of the system to operate more efficiently
3. Are there problems with installing the tank in the loft - ie tank bursting and scalding inhabitants below

can anyone offer guidance on points 1 to 3 please?

1. The tank-in-tank, ACV is the best. The CH can also be run off these as well. They re-heat very quickly.

3. No problems in the loft.

4. It will cost you an annual service charge for the unvented cylinder negating any economic advantages of solar, etc.

If you want solar in the future go for a thermal store/heat bank.

 

[rmwilford]

As for solar. I did say 'should you' not 'you must'. Meaning you could invest in a vessel that has the necessary spare coil which will not cost much more than standard versions.

Agreed and a very good idea. "Future-Proof" as a good friend would say!

 

[Agile]

I agree that if you are of the opinion that you want to invest money in a solar system just to be green then get a system suitable for solar as it will save about £100-£150 per annum.

But to get that saving you must spend about £2000 on the panels and controls alone with out installation. Installation and a solar unvented cylinder or thermal store will add another £2000 upwards.

So a return of £100-£150 p.a. on an outlay of nearly £5000 ? And that excludes the maintenance of about £80 p.a. for a sealed system.

Tony

 

[rmwilford]

If you want solar in the future go for a thermal store/heat bank.

Hmm, it's hard work this - I just keep going around in circles. But then it's always said that if you ask 10 heat engineers you'll get 10 different answers. Advantages to all solutions so I've got yet more considering to do.

I was really considering a heat bank. The DPS Pandora. There seems to be a lot of support from anyone who's used/fitted them. Are they physically any larger than the components of ,say, the EcoTec 937? If I have a good supply flow rate and pressure are there any disadvantages to a heat bank? i must admit, I'm probably struggling to find any - very efficient, not expensive to install, cheap to maintain and with a "store" that could ultimately link to renewables.

 

[rmwilford]

So a return of £100-£150 p.a. on an outlay of nearly £5000 ? And that excludes the maintenance of about £80 p.a. for a sealed system.

Not worth it at the moment, I agree. It was solely a consideration so I might have the option to retro-fit in the future.

 

[Nixt]

I agree that if you are of the opinion that you want to invest money in a solar system just to be green then get a system suitable for solar as it will save about £100-£150 per annum.

But to get that saving you must spend about £2000 on the panels and controls alone with out installation. Installation and a solar unvented cylinder or thermal store will add another £2000 upwards.

So a return of £100-£150 p.a. on an outlay of nearly £5000 ? And that excludes the maintenance of about £80 p.a. for a sealed system.

Tony

Apply that logic to any major purchase and the investment will not make sense.

 

[BigBurner]

If you want solar in the future go for a thermal store/heat bank.

Hmm, it's hard work this - I just keep going around in circles. But then it's always said that if you ask 10 heat engineers you'll get 10 different answers. Advantages to all solutions so I've got yet more considering to do.

I was really considering a heat bank. The DPS Pandora. There seems to be a lot of support from anyone who's used/fitted them. Are they physically any larger than the components of ,say, the EcoTec 937? If I have a good supply flow rate and pressure are there any disadvantages to a heat bank? i must admit, I'm probably struggling to find any - very efficient, not expensive to install, cheap to maintain and with a "store" that could ultimately link to renewables.

Look at:
http://www.advanceappliances.co.uk/

They do thermal stores (internal coil DHW take-off). They will do the heat bank (external plate heat exchangers) too. They will also make to order too. They are cheaper than DPS.

 

[BigBurner]

So a return of £100-£150 p.a. on an outlay of nearly £5000 ? And that excludes the maintenance of about £80 p.a. for a sealed system.

Not worth it at the moment, I agree. It was solely a consideration so I might have the option to retro-fit in the future.

Solar will increase the value of your house.

 

[Agile]

On our solar course the enthusiast trainer produced a survey which showed that a solar installation had no significate effect on the purchase price.

Even if that was true, which I wonder, I would have thought that with two houses otherwise identical the solar one would sell first. Or perhaps housebuyers are suspicious of "new systems".

However,