Envirovent/whole house ventilation - any good?

[AshG]

Hello all.

Apologies if this has been posted before as a topic - the search facility seems to be down so I couldn't check.

I've recently moved into a maisonette with thick hard walls and piss-poor ventilation. Yep, you guessed it; condensation and black mould on walls and window frames. I've invested in a dehumidifier, which is very effective in the one room its positioned in but doesn't do a great deal for the rest of the house. Plus, I'm concerned about my 'leccy bill. And I'm sick of cracking open the windows all over to increase ventilation. Especially in this bloody freezing weather.

Just saw an ad on the telly for Envirovent and their whole house ventilation systems. Anyone have any experience of them or similar systems? Any good? Any other recommendations for dealing with this sort of issue more comprehensively? I reckon Envirovent might be rather pricey but I'd really like to nail this problem on the head once and for all.

Thanks in advance!

[AshG]

I should perhaps mention that the system that interests me is the Envirovent Mr Venty wall unit, as I don't have loft space to install their other units in.