Flow Rate Reqd for Thermal Store/Heat Store

[baggy99]

>> don't understand why unless you want to fit it yourself

Yes, I'm DIY-ing it, so its gotta be vented.

 

[Doctor Drivel]

He likes heat stores.

I'd put in an unvented and if there are any issues at all about flow rates, add an accumulator, job done. If you have to have a heat store (don't understand why unless you want to fit it yourself) you can bung an accumulator on the front of that.

Best get to know thermal storage. The store acts as a neutral point, in which the boiler, CH and DHW act very independently of each other, and not affecting each other, and can be maximized for efficiency. The CH can have TRVs on all rads and no central thermostat to switch out the whole heating system, giving full interrupted local temperature control in each room, using a Grundfos Alpha or Wilo Smart pump. If the CH requires only 0.5 KW the store will supply that and no inefficient boiler cycling which can cut short a boilers lifespan dramatically. Only a simple, cheaper, fixed burner rate boiler need be used. The buffer effect for CH is well worth having. It enhances boiler efficiency, running only long efficient burns. It also gives instant high pressure hot water as well

The benefits are immense all around and no more expensive than a boiler/unvented cylinder setup. The only way to go.

 

[Doctor Drivel]

>> don't understand why unless you want to fit it yourself

Yes, I'm DIY-ing it, so its gotta be vented.

A pressurized thermals store can be DIYed. No G3 ticket is needed for these. Nu Heat do a stainless steel pressurised thermal store - only low pressure, not like the 4bar and above of unvented cylinders:
http://www.nu-heat.co.uk/s.nl/it.I/id.394/.f

Download the brochure.

 

[gas4you]

The CH can have TRVs on all rads and no central thermostat to switch out the whole heating system

Wheres the boiler interlock then as required by building regs other than with the Vaillant VRC400?

I've got a thermal store unfortunately. What a load of inefficient crap

Only new build usually fits them as they don't need G3 qualifications. Cheap skate developers

 

[Doctor Drivel]

The CH can have TRVs on all rads and no central thermostat to switch out the whole heating system

Wheres the boiler interlock then as required by building regs other than with the Vaillant VRC400?

The boiler interlock is the stat(s) on the cylinder controlling the boiler.

I've got a thermal store unfortunately. What a load of inefficient rubbish

It must be an old immersed coil type - the heat banks using plate heat exchangers are far better. . Doe the CH run from it?

Only new build usually fits them as they don't need G3 qualifications. Cheap skate developers

They are cost effective to install and run. The boilers last as they are always running at optimum performance.

 

[Doctor Drivel]

The CH can have TRVs on all rads and no central thermostat to switch out the whole heating system

Wheres the boiler interlock then as required by building regs other than with the Vaillant VRC400?

The VCR 400 is weather compensator controller, that plugs in to their boilers. That will provide the interlock with a room influence temperature sensor.
http://www.vaillant.co.uk/Home/Prod...ukt_vaillant/VRC_400_Weather_Compensator.html

 

[simond]

You can't get a room influence temp sensor with a VRC400. You have to mount VRC400 external to the boiler and invoke the internal NTC if you want room temp control.

I don't think you should give advice until you start fitting this stuff; your posts suggest you have the practical fitting and maintaining experience when you do not.

Similarly with heat stores; we can all read the manuals in the bath but I have more respect for the views of the person that dragged it out the van, installed it and maintained it for their customers.

 

[Doctor Drivel]

You can't get a room influence temp sensor with a VRC400. You have to mount VRC400 external to the boiler and invoke the internal NTC if you want room temp control.

Which is he same thing.

I don't think you should give advice until you start fitting this stuff; your posts suggest you have the practical fitting and maintaining experience when you do not.

As you do not know me you are in no position to comment. I advise you to get to know something about thermal storage before commenting too.

Similarly with heat stores; we can all read the manuals in the bath but I have more respect for the views of the person that dragged it out the van, installed it and maintained it for their customers.

I have more respect for the views of people that know them and what they do. I know many that have fitted them not knowing too much about them at all. They tend to be people that post on places like this forum.

 

[gas4you]

How can stats on the cylinder know what temperature the rooms are, they are just water based from the store and will not prevent boiler from firing if rooms are up to temp.

The VRC 400 does this by pre-programmed heating curves that the installer selects upon commissioning.

My Thermal store is 2 years old Gledhill. with 3 pumps and a plate heat exchanger for the hot water, but it's still crap! Just a combi really for the hot water side, which you can notice when several hot taps are used at once.

If I set the boiler stat to 50-60C then I don't get the required perfomance needed, so therefore has to been run hot and inefficiently.

I will never accept that the working principles of thermal store can co-exist alongside a condensing boiler.

 

[Doctor Drivel]

How can stats on the cylinder know what temperature the rooms are, they are just water based from the store and will not prevent boiler from firing if rooms are up to temp.

The TVRs know the room temperatures. The boiler only heats a store of water controlled by stat(s) or an electronic board as is the Gledhill.

The VRC 400 does this by pre-programmed heating curves that the installer selects upon commissioning.

It doesn't. It acts on the curves, depending on outside temp and/or flow or return or both temp. The house can still get too hot, say solar gain to the south side.

My Thermal store is 2 years old Gledhill. with 3 pumps and a plate heat exchanger for the hot water, but it's still rubbish!

You come out with general statement and do not qualify. What is rubbish? What model is it? A DHW only model or an "integrated" CH & DHW? Gledhill make good stuff.

Just a combi really for the hot water side, which you can notice when several hot taps are used at once.

Same as any mains pressure system: combi, t/store.unvented cylinder.

If I set the boiler stat to 50-60C then I don't get the required performance needed, so therefore has to been run hot and inefficiently.

What model? Heat directly or indirectly from the boiler? It may be too small for your needs as well. A larger store means a lower store temp. When you run a bath the return water to the store is very "cool", this promotes condensing efficiency in the majority of the re-heat time, even if a high store temp.

Put a blending valve on the flow/return of the boiler to the store. Set the store to 75C. Find the delta T of the boiler, say 22C for a condenser. Set the blender to return 53C to the boiler, You can probably get away with 50C.

I will never accept that the working principles of thermal store can co-exist alongside a condensing boiler.

You will have to, as they do. I have seen them operate as low as 60C and give 55C DHW temps.

A condensing boiler heating the store directly has no intermediate losses. A plate heat exchanger is highly efficient, far more than an internal DHW coil. Both of these points, with a properly sized store means that the store temperature can be quite low indeed, promoting condensing efficiency through most of the re-heat.

Look at the ACV site, Their Heatmaster. condenses all the time. Download the info it explains it all.

 

[simond]

Here we go again, another load of manufacturer bumpf to read and believe implicitly. This time we are all sent to ACV. Would this be the Belgian company I have requested literature from, twice, and received nothing?

The VRC 400 does this by pre-programmed heating curves that the installer selects upon commissioning.

It doesn't. It acts on the curves, depending on outside temp and/or flow or return or both temp. The house can still get too hot, say solar gain to the south side.

The VRC400 has an inbuilt thermister so it can sample internal temperatures. It doesn't mention that in the web guff, so you wouldn't know that, Dr Driv. You have to be an installer to know.

Anyway, the OP has an oil boiler and Vaillant don't make one for the UK, the VRC is not compatible with non Vaillant gear.

 

[esra_ptrap]

Doctor Drivels posts remind me of another keen thermal store advocate who has been long time absent ... WaterSystems!

Could they be one and the same by chance

 

[Doctor Drivel]

Here we go again, another load of manufacturer bumpf to read and believe implicitly.

No having worked with them. Do you have any proof their claims are false?

This time we are all sent to ACV. Would this be the Belgian company I have requested literature from, twice, and received nothing?

Probably.

The VRC 400 does this by pre-programmed heating curves that the installer selects upon commissioning.

It doesn't. It acts on the curves, depending on outside temp and/or flow or return or both temp. The house can still get too hot, say solar gain to the south side.

The VRC400 has an inbuilt thermister so it can sample internal temperatures. It doesn't mention that in the web guff, so you wouldn't know that, Dr Driv. You have to be an installer to know.

So it does measure the inside temperature then.

Anyway, the OP has an oil boiler and Vaillant don't make one for the UK, the VRC is not compatible with non Vaillant gear.

Yep. And he wants a heat bank/thermal store.

 

[Doctor Drivel]

Doctor Drivels posts remind me of another keen thermal store advocate who has been long time absent ... WaterSystems!

Could they be one and the same by chance

There are lots of thermal store advocates around. Those who understand heating.

 

[gas4you]

[quote="Doctor Drivel
The TVRs know the room temperatures. The boiler only heats a store of water controlled by stat(s) or an electronic board as is the Gledhill.

So wheres the boiler interlock then?, you missed that on google I take it!

It doesn't. It acts on the curves, depending on outside temp and/or flow or return or both temp. The house can still get too hot, say solar gain to the south side.

Wrong again, the installer sets the curve, the room with solar gain will be controlled by the TRV in that room. A southerly room will not be affected by the outside temp sensor as it is never fitted on a southerly wall

You will have to, as they do. I have seen them operate as low as 60C and give 55C DHW temps.

I don't have to do anything. No customer of mine will ever have the misfortune of getting a thermal store fitted. I'll leave that to the cowboys who think they know what they are talking about.

You obviously haven't a clus about Vaillant boilers or system controls other than as Simon says, looking up the info that is on their site.

I am fortunate to have info that hasn't even been publicly released from Vaillant, so bring it on (not that I would ever pass it on to someone who sounds incompetent )