Goldfinch

If your French is up to it, there is a VERY detailed TOP 15 mvhr list on a Belgian DIY site that includes the Salda Smarty. You need to ask for a password to read it - they want to keep commercial activity off the site. They gave it a very good rating - high quality products, excellent documentation and clearly built for cold climates. The downside was a bit noisy and disappointingly expensive. Being rip-off France and Belgium, the price is around 2,700 euros!! It's an absolute bargain at bpc. The website is bricozone.be/vmcdf and the list is titled Quelle VMC-DF choisir ?

Ooh, yes, the HVAC stuff looks useful for pressure drops and duct sizing. Thanks.

They don't seem to do that here in France. What's more I'm only investigating the possibility of MVHR, so I'm not sure they'd want to do that for me. Since posting, I have, however, found a free program provided by the Belgian version of the BRE. It is very detailed and will design your system for you! Two catches; it specifies to Belgian regs and is in French. It's at cstc.be. Does drawings and everything

I'm leaning towards a demand controlled c-MEV (Renson Healthbox 3) which has varying sensors on each intake (H2O, VOC, CO2). However, such a fancy system costs around 1,400 and the ductwork isn't much less than an MVHR in my case (3 stories, all rooms but one around a central stairwell). I want to see how much an MVHR system would cost in terms of time and money so need a design for airflow, ducting, fan capacity etc. I can't find any books to help me, I can't find any methods on the Internet and I can't help wondering why. Can anyone tell me where to find a guide to designing it? I bought a book in French but it mostly just set out their Building Regs rather than provide a 'How to'.