Wood pellet and Multifuel Stoves - Advice needed

Mellor

I'd like a bit of feed back on the above. (stoves, not boilers)

The idea is to get a WP or MF stove to heat the kitchen/dining area. The room is in an extension and gets quite cold. Total area is about 40 sq.m
Its actually my dad who is getting it, and the problem the sales pitch is contradicting my advice. Need a second opinion.

Few small things, I am aware that a grant of €1,100 or €1,800 (depending on backboiler) is available, the approved product list is limited. I'd like to get one approved, but not a must. In fact, it may not even be possible, as we have our own source of pellets, self made almost, they are much larger than the standard ones. Each the size of a tea mug. Their make up is the same, very dry sawdust, but because of multi-fuel stove suits these better no grant available (no grants for multifuel)

Ok, so questions

1. What size stove (in KWh) is needed to heat a 40 sq.m room. I am getting conflicting advice from manufacturers. Each seams very high compared to the KWh boiler needed to heat a house
   
2. What sort of effciency should be sought? I thought that 90%+ was common.
   

Basically, I know that a 25KWh boiler (about 90k Btu) will heat a moderated house. Scalling down I was expecting a much smaller stove for a room.
Any help guys?

wazzoraybelle

We have a 9kw dru multifuel stove that heats about 40 sqm effectively, We only burn wood and compressed wood briquettes in it and once you get to know the stove it can heat this space quite quickly.
It cost 1350 excluding flue and installation.
it doesn't burn overnight on wood but should do with coal. It's pretty maintanence free and we empty the ash pan once a week.
The area it heats consists of three adjoining rooms with 8ft ceilings and the stove will burn about 2.50 euro worth of briquettes over 6-8 hrs.

We love ours, hope this helps.

Mellor

Thats what was reccomended, but 9KWh seams huge to me,
a 25 KWh boiler will heat 200 sqm

wazzoraybelle

I wouldn't risk anything smaller and end up with a room that doesn't heat up effectively. The stove itself isn't that big 3'hx2'wx1and half deep. The efficiency of the stove is 75% ( 78% if left burning constantly).

Mellor

I understand what you say about risk of not heating up, this will happen with an undersized stove, but the correctly sized stove will heat the room better than an over sized one. I have a pretty green agenda also. Waste not want not.

75% is pretty poor efficiency, i'd be looking for one closer to 90%.

Size of the stove is not a huge concern, the space for it is 900x700x1500

wazzoraybelle

If you have a bit of space, why not consider a masonry stove?

sydthebeat

without being inany way an expert, but the output required from the stove should be pro rata to the insulation levels. The better the insulation levels the less output needed.

It will be hard enough get a wood burning stove at 90% efficiency.

Its interesting to note that currently there is NO solid fuel burner in the HARP database, even the aga one thats up states it has an efficiency of 0, which is obviously a mistake.

Mellor

sydthebeat wrote: »

without being inany way an expert, but the output required from the stove should be pro rata to the insulation levels. The better the insulation levels the less output needed.

It will be hard enough get a wood burning stove at 90% efficiency.

Its interesting to note that currently there is NO solid fuel burner in the HARP database, even the aga one thats up states it has an efficiency of 0, which is obviously a mistake.

For phase 2 grants the min efficiency for wood stoves is 80%

Currently there are two brand registered, at least one of which operayes at 90%


Anyway, 80-90% is minor, I more concerned with the output. As for it being pro rata to insulation, assume a low to average level (average being current regs), but most of the walls aren't exposed