The baffles would be between the two flue elements, the ceramic/masonry part (heat recovery) and the stainless steel flue (remove gases from the building) This prevents all that stored energy heating the garden.
Think it suits passive house or similar well insulated, reasonably airtight buildings with low thermal mass.

We're in a rented old house now that has two stoves in two fireplaces, as well as a gas combi boiler that has lots of big radiators. We don't plan on using the stoves - we've no free fuel so they're just extra work. From what I'm reading in this thread, it seems it may be well worth packing the fireplaces with insulation to isolate the stoves from the room. Does that sound sensible, totally lunatic or just overkill? I'm thinking of the kind of fluff that comes in ready to use poly bags.

Posted By: jms452If the stoves run on house air and can can be nominally closed off this is at least overkill (I assume your rented house doesn't have MVHR so you need some natural ventillation anyway).

I haven't looked at them that closely yet. I believe they run on room air but I've no idea about closing them off. But we're quite capable of opening windows :)

If you forget to take out the insulation when you leave it is also potentially dangerous.

I think I'm contemplating something different to you! I'm thinking about wrapping the stoves in insulation, not putting insulation up the flue.

These are passive house details, exaccerbated by unbaffled direct air stoves, that frankly in any rented house I have ever been in are in the noise.

I guess I'll wait and see how cold they get then.