Combining 2 heat sources into one coilin the hot water tank

[FINI]

Is it possible (by using one way valves etc) to run hot water from a solar panel and from a stove into the same coil in a hot water cylinder.
I know it is possible to purchase tanks with 2 coils but that is more work and expenxe and more often than not when the solar panel is heating water the stove will be off.

 

[spudkey]

how about replacing immersion heater with a coil

 

[Balenza]

Is it possible (by using one way valves etc) to run hot water from a solar panel and from a stove into the same coil in a hot water cylinder.
I know it is possible to purchase tanks with 2 coils but that is more work and expenxe and more often than not when the solar panel is heating water the stove will be off.

Consider one of these.
http://www.willis-renewables.com/default.htm
Developed for situations like yours where a cheap and viable solution is necessary without going to the expense of costly cylinder replacements.

You might catch the video here if it works.
http://www.willis-renewables.com/video.htm
Its a simple animation (for those with difficulty understanding the science bit) showing clearly why directly heating a cylinder from the top down has advantages over a coil system.

 

[chrishutt]

Its a simple animation (for those with difficulty understanding the science bit) showing clearly why directly heating a cylinder from the top down has advantages over a coil system.

Looks like a scam to me. I have difficulty understanding the science because the links don't attempt to explain the science. Balenza **************** thinks it is a direct heating device rather than a heat exchanger - nothing I can see on the links suggests that.

 

[chrishutt]

It is a direct heating device.
It heats the cylinder directly .... as opposed to using an internal coil which is inefficient in comparison.

It clearly uses a heat exchanger very like a coil. It is not direct, it is indirect. It's just an expensive and unnecessary alternative to adding a second indirect cylinder to convert an existing cylinder to solar.

 

[Paul Barker]

Why not go direct?

Use the standard gravity cylinder (old direct cylinder from scrappy) as a drain back storage device. Pump from the cold feed directly up a small diameter pipe to the top of a flat plate collector,(old radiator, heat retained by old double glaised patio doors etc etc) let it fall back through the collector down a wider boar pipe to the top of the direct cylinder. Pump controlled by light sensetive resistor.

Proper carbon footprint jobby.

Now where was that Grant money?

For carbon effect to be maximised use hot water at times available.

The problem is most people pretending to be green are just spending money on a hobby horse, self satisfaction and dinner party conversation, or are trying to secure planning permission for expansion.
TYhe payback period on commercial offerings and carbon footprint involved in unnecessary manufacture and paying the infrastructure of organisations including universities goes far beyond the useful life of the equipment.

People who really wan to be green build an earthship.

 

[Balenza]

Is it possible (by using one way valves etc) to run hot water from a solar panel and from a stove into the same coil in a hot water cylinder.
I know it is possible to purchase tanks with 2 coils but that is more work and expenxe and more often than not when the solar panel is heating water the stove will be off.

To keep it simple just use a twin coil vented cylinder. One coil for the boiler and the other one for the solid fuel stove. Their common place in the sticks.
For the integration of the Solar use the Willis Solasyphon or use this which utilises the thermosyphoning priniciple also ...

Which is available from DPS (Dedicated Pressure Systems)

 

[Paul Barker]

High Balenza,

I don't see the need for a sealed system? Is it just that certain panels won't operate properly on the drain back system?

On your last link is there a pump on the dhwc side of the external plate heat ex? I imagine one is required.

 

[Balenza]

Paul Barker wrote

I don't see the need for a sealed system?

Then why the need for a drain back system ? Because the drain back is more superior ?.
I think the Netherlands have 80 percent drainback systems installed so they are most certainly successful from that point of view.
However I think they are installed mostly on flat plate collectors and thus are able to withstand the thermal shock much better on occasions when cool water is pumped through.
Draining back will not stop the panel from reaching exceedingly high temperatures.

Is it just that certain panels won't operate properly on the drain back system?

I think this is the case.

On your last link is there a pump on the dhwc side of the external plate heat ex? I imagine one is required.

No pump. It uses thermo-syphon (gravity) circulation on the store side. Though I suspect the PHE is selected accordingly.

 

[Agile]

At Installer Live there were about five different design panels on show.

All were promoted for sealed systems.

Just one was a design suitable for the ( superior ) drainback system and the salesman did not even know about it.

Its rarely used but an external plate heat exchanger is a much cheaper option than an extra coil and even enables an existing cylinder to be used on solar.

The latter solution does not make much money for the installer and none of the companies are promoting it because they want a £3000 chunk of sales in one bite.

Another way is to fit a second cylinder in series with the solar heating the first cylinder. Another cheaper option using a standard cylinder!

The only way that solar can give a payback is if cheaper options are used.

Tony

 

[Paul Barker]

here here

 

[chrishutt]

here here

Er, that should be hear, hear actually, as in hear him, hear him. Lots of people get that wrong.

 

[Paul Barker]

nice one, but you are lucky I spelt it at least one way correctly.

But I hear you