No real expertise really yet some experience.You may need a fresh air input directly to the wood stove. If the windows are sealed well and the structure is pretty tight overall. With concrete wall and floor construction I might suspect that by the way.

When the stove is running you might be developing negative pressure inside the house as well as a result . So the stove is going to smoke more when fuelling especially. Also might run poorly as well producing more combustion by products than otherwise to leak out into the inside enviroment.

By code we have to install heat exchanger systems in new home construction now in Canada.. The homes are just far too tight.

Examining those residential type heat exchange units. The efficiency of heat transfer between the incoming and outgoing air raises some questions in my mind. More show than go and hype than reality comes to mind.

I suspect the heat transfer is really very poor just better than none perhaps. Depending on other heating alternatives burning wood costs to the individual have to be looked at. How many cords are you burning a heating season on average?

You will always have to paint etc far more often and there are some health issues as well. And dirt is generated from wood in the handling. Yet if the wood itself is basically free other than cutting and splitting and handling it. It is a cheap heating source.

The economics of a concrete structure from an energy requirement perspective may be poor as well. Modern concrete domestic structures in north america have finally dealt reasonably well with the insulation issue. Not so well with the older ones usually.

So my limited thoughs are to try a direct to the stove a fresh air input from outside for combustion air first. This will also eliminate any chance of a negative pressure differential between the outside and inside developing. As far as the stove is concerned anyways.

Also examine the stove and flue setup very carefully for deficiencies in design or installation. An outside brick flue in a cold climate especially if oversized can be an issue. There are ways to deal with that.

All stoves for example are far from created equally. Also you might want to set up on the cheap and do an air change per hour calculation on the house. This will tell you if you really need an exchange system as well I suspect.

The principal reasons for air exchangers are to deal with excess humidity in a tight dwelling and to make sure you are not living in stale air. This is about the extent of my very limited knowledge in this area. Others will know a lot more. Other than I would tend to do a few tests of various types before deciding what is either required or the best way to spend the dollar. For example if the structure had several air changes per hour and no humidity issues I would not install an air exchanger. Concentrating more on why there is more smoke present in the house than should be present. Burning wood unfortunatly there will always be a small amount but it should not be noticeable in daily life.

Modern concrete home construction in north america utilizes two layers of foam insulation used as forms. A lot of rebar in them and this void filled with concrete. These houses should not from an economic perspective need to utilise wood heat except perhaps for a backup. Since your home is a modern european version if this type of construction. If it was properly done I would have expected it to be really tight and cheap to heat overall. So you would need the fresh air input to the woodstove and probably an air exchange unit as well. That depends on the climate a little though. Current methods of construction are kind to the concrete walls for example. They do not go through the typical freeze thaw cycles that a lot of previous concrete houses did. R insualtion values of the walls perhaps are about R twenty eight or more hopefully. Certain foams can be quite a bit higher R value wise. I have not built or investigated one of these myself so just do not know.

I would not heat with wood if the construction is much as I describe. It should be cheap to heat in my opinion unless the glass area is excessive or it is extremely large or there was a less than a really modern type of construction employed. The amount of cords of wood you are proccessing per season will answer that. Less than three cords I would pack in wood heating for sure at north american energy costs. Maybe even at less than four cords. As always though these are just my opinions and others will vary.