reducing output while keeping efficiency

[spluger]

hi guys i put forward a question/idea that i hope the collective may have answers for or even have tried

I've got a firebelly FB1 and am very pleased with it
however its 6kw and sometimes is too much so i was wondering instead of running it cool ie vents closed (low efficiency) how about making the fire box smaller.
the idea would be to purchase some more vermiculite fire bricks and double up on the sides and back, thus reducing fire box size and upping the insulation = hotter smaller fire

the reasoning for this would be during milder weather when some heating is still needed

flebay sells sheets of the fire bricks which can be cut to size / shape


do you guys think its worth trying?

cheers

David

[Bodidly]

I have often thought of doing this but somehow never get around to it. My only concern is concentrating the heat on one area that for some reason does not cope. If you do give it go I for one would love to hear how well it works.

Good luck
Beau

[ecogeorge]

Good point , but if you don't let the heat out , ie fit insulating firebricks where is the heat going to go ? up the chimney ?
Does anyone know ?

[Heinz]

I add a couple of ex nightstore heater firebricks to one side of my stove for the summer, so the firebox is half the width. Works well and they can be lifted out with the tongs if the weather goes colder than expected.

Heinz

[CeeBee]

Good point , but if you don't let the heat out , ie fit insulating firebricks where is the heat going to go ? up the chimney ?
Does anyone know ?

I think he's suggesting adding more firebricks to where there are already firebricks, so not 'preventing heat from getting out', and of course the idea is to reduce the size of the fire (while still allowing efficient burn) so there should be less 'heat' (energy).

I don't imagine stoves will a smaller quoted output differ much from those with a high output other than by having a smaller firebox, so the idea sounds good to me.

[Richard Owen]

Like Heinz, I've added some old storage heater bricks to make stove volume smaller. I went too far and had to take two of them out because the fire didn't get going at all.

Good thing about this approach is that you can play with it until you get something you're happy with.

An angle grinder will cut storage heater bricks easily enough if they don't fit in original form.

[spluger]

oh good sounds like it should work then

no i just need some money left and the end of the month and i can get some to try.


Cheers guys

David

[Treebeard]

I use storage heater bricks in the Esse Ironheart all year round. It does not appear to have had much of an impact on the output of the stove. The oven still gets up to the same temperature as without firebricks.

[Treebeard]

Just make sure that the bricks are thoroughly dry before putting them in the stove.