underfloor heating and water powered by duel fuel burner

[diyisfree]

Hi all,

I'm in the process of building a dormer bungalow and we coming to the first fix stage, we are wondering the best way to heat and provide water for the bathrooms. The bungalow is 5 bed room 2 bathrooms and 2 en-suite,

The total downstairs floor area is aproximatly 180 sq meters. We have built a large ingle nook fireplace with the intention of getting a duel fuel burner that will also heat hot water and provide central heating. We have thought about a wet underfloor heating system with rads upstairs. In our current bungalow we have a zone valve fitted with duel thermostat control so we could run the heating upstairs independently from downstairs, idealy we would like this again.

We were thinking of going for a presurised hot water cylinder in order to provide enough hot water for both bathrooms and the en-suites. Is it possible to marry a duel fuel burner along with a combi as a summer means of heating water ? Or if its very cold we can kick in the combi to help the fire heat the water a little better ?

We were thinking of letting the combi supply just the kitchen with water in order to keep it from sitting there doing nothing.

I know all this is pretty brief but i dont want to go into detail if the project is a non starter from the begining.

Any advice would be greatfuly received.

cheers

 

[diyisfree]

guess its something that has never been asked before then ?

 

[Norcon]

Its all possible. Post this up on Navitron.
Theres a guy over there at the moment fitting four solid fuel boiler stoves in his home and linking them all together. Reckon he'll need a jutland horse to haul logs to them.

Nothings impossible but you need the right installer.

 

[Onetap]

guess its something that has never been asked before then ?
Doing It youself is free. Sorry but I have to feed the kids

I'd give you my professional advice for free, but sorry, I have to feed my kids too.

You need a G3 registered installer for an unvented (mains pressure) hot water storage cylinder and you won't find many that would consider connecting a cylinder to a solid fuel fire. You'll find something in the archives about it.

 

[ajrobb]

First, I am Mechanical Engineer and not an RGI nor G3 installer.

From OneTap's comments, maybe wood burners are too uncontrolled for safety with an unvented cylinder. Your dual-fuel burner supplier should be able to advise about using an unvented cylinder. You might want to consider a bronze pump to circulate hot water to the 4 bathrooms.

If you can't have an unvented HWC, you might consider a thermal store. With a large TS you could run plate heat exchanger(s) for DHW (like a huge combi). I have seen others advise the use of an internal coil to power either CH or low-flow DHW (before the pump to the plate heat exchanger kicks in with the flow sensor). With a TS, you don't have to heat the DHW to 60°C only to be cooled down again by thermostatic mixers.

As you suggest, a combination boiler can be used to heat a HWC. A slight reservation is that it will not have separate temperature controls for CH and HWC. This means you are probably stuck with inefficient non-condensing operation much of the time as your flow temperature must be up around 70°C just to heat the HWC to the legal minimum of 60°C (for legionella control). However, this might be unimportant if you get most of your heat from the dual-fuel burner.

 

[RichieHoneybucket]

Can all be done with a Dunsley Baker nautralizer.

 

[diyisfree]

Thanks guys for all your input, It was just ideas we were kicking about but it sounds as if this is going to run into several thousand pounds just for the materials alone,

Lets put it another way, If it were your house (as pro installers) what would you do? for your own use?

May just go down th route of having the duel fuel burner for the central heating then,