Oil Heating (Woodburner Savings)

[swoodley]

Hi All,
I've looked at past posts but can't see any topics that cover this specifically and wondered if anyone can help?
We will be installing underfloor heating and are wondering on the cost/benefit of integrating a wood-burner with an oil condensing boiler (unfortunately no mains gas anywhere close, we are also limited on solar as there isn't anywhere to locate the panels - short of sticking them in our next door neighbours field!).
I think that potential savings mean we should integrate, but my husband isn't so sure. I know it would be a real 'guesstimate' but does anyone have any idea of possible savings by doing this?
Thanks in advance
swoodley

 

[DaveBrigg]

A lot will depend on the size of your property, and what you consider to be a comfortable temperature. And of course on the price of oil, which will probably have increased by the time I finish this sentence. We have a wood fuelled boiler in the garage which runs off scrap wood from a nearby industrial estate. It's a lot more work than oil, but over the winter, friends in a similar sized house were paying nearly £200 a month for oil, so we're not thinking of going back.

 

[christianb]

We live in a small 17th century cob cottage and our primary source of heating is a solitary woodburner. Okay, we put on a couple of electric radiators on the cold, cold, cold winter nights, but an open fire / burner is far better for the health of the house than any other form of heating.

And it costs nowt to run.

 

[Alastair]

We have the same as cristianb, but live in a Victorian semi (with extension). There's no heating upstairs, but we don't go there if it's cold, except to bed. No double glazing, not much draught exclusion. Wood for evening heating, about £150 a year. Matalan sell very cheap fleeces/sweat shirts/jumpers.

 

[Lime]

We have the same as cristianb, but live in a Victorian semi (with extension). There's no heating upstairs, but we don't go there if it's cold, except to bed. No double glazing, not much draught exclusion. Wood for evening heating, about £150 a year. Matalan sell very cheap fleeces/sweat shirts/jumpers.

One of the reasons that I have central heating is because of the cold that I remember from my childhood.
Waking up to see the mist of your breath, ice on the inside of the window frame and freezing cold lino made getting dressed a chilly experience.
It used to be a major celebration of Christmas to have open fires in more than one room.
However I think we were healthier in those days apart from the odd death!

 

[Aidan]

We will be installing underfloor heating and are wondering on the cost/benefit of integrating a wood-burner with an oil condensing boiler (unfortunately no mains gas anywhere close, we are also limited on solar as there isn't anywhere to locate the panels - short of sticking them in our next door neighbours field!).

UFH has a low flow temperature, typically 40 degC ish (wild guess because i can't be bothered to get a book out).

It can only provide a limited heat output whilst staying below the recomended maximum floor surface temperature (27 degC, ISTR; can't be bothered to get the other book), so it often has little impact on the peak heating load in old buildings with period insulation, single glazing, etc..

You can keep to the low flow temperature with a condensing boiler by modulating the burner, or cycling it on and off, controlled by the flow temperature.

You can't do this with wood fired boilers because they aren't condensing and they don't modulate or cycle on and off; they're lit or they're not. The only way of doing it (assuming it's not a huge house and a small wood burner) is by using a thermal store (big insulated water store) to accumulate the heat from a wood burn and then blend the flow and return water from the thermal store, as required by the UFH flow temperature, using a mixing valve system.

You could connect a conventional boiler into the thermal store, but I haven't fathomed out the logic of condensing boilers used with thermal stores. Someone will suggest you use a neutraliser.
Forget solar for space heating in the UK.