Thermal store for combining heat sources?

[solveweb]

Hi.

I know there are other threads discussing thermal stores vs combi boilers etc... But there is nothing that recent, and nothing specifically concerning combining heat sources....

I am doing a refurb including fitting a new heating and DHW system. We will initially be getting a new condensing Grant Vortex oil boiler, but I would definitely like to add on solar thermal panels, and I will also be adding PV and would possibly like to use surplus electricity to top-up heating via a 3KW immersion element.

Eventually, maybe, I would look to add a wood burning stove with back boiler or GSHP.... I want to keep my options open on that though.

Should I be going for a thermal store? Will the thermal store allow the oil boiler to operate efficiently? What if I never ever get around to adding the wood burner? I've been looking at the eco-equipped model. It looks great, but its just very expensive compared to a tank. Is it worth it? Whats the current view on all this?

Many thanks in advance.

 

[Agile]

You could ask your oil boiler installer for advice.

Usually you need a thermal store when you are burning wood or other uncontrolled heat source.

But unlikely to offer any significant savings unless you have unlimited wood available as well as the EFFORT to prepare it for 30-40 minutes a day!

Little point in adding the thermal store until you are ready to fit the wood burner or any solar thermal panels.

Tony

 

[solveweb]

Little point in adding the thermal store until you are ready to fit the wood burner or any solar thermal panels.

Thanks Tony

I will be getting solar thermal this year definitely. My point was though, that I don't want to waste a few hundred quid on a DHW tank that's suitable for oil + solar coil, and waste money running pipes back to oil boiler for CH, when I am eventually going to maybe need to get a thermal store if I want to add in further heat sources.

To my mind (although I am certainly no expert) the pros of getting a thermal store now are:

- I will not waste money buying anything not suitable for the system later
- I will not waste labour running pipework to the wrong place
- A solar thermal connected to a heat store (rather than a tank) means solar thermal can contribute to CH as well.

The cons:

- Cost of the thermal store
- Possibly it might affect efficiency of the oil boiler (although I would appreciate advise on whether this is a valid issue)

I just need to know how big an issue the effect on efficiency is or could be, and whether there is anything else I should be considering when designing this system.

 

[onecog]

Have a read on this forum and you might get some good tips.

http://www.navitron.org.uk/forum/

 

[Agile]

- A solar thermal connected to a heat store (rather than a tank) means solar thermal can contribute to CH as well.

Solar can only contribute to just hot water for most of the year! For perhaps five or six weeks of the summer it can provide all the hot water as long as the tank is large enough to cater for the daily needs.

Dont get taken in too much by solar PV hype either!

Tony