I have a condensation problem and understand that fitting a passive humidity vent would go some way to alleviating this problem.
The difficulty is that I have been recommended three specific units at similar prices but had no idea which is the best.
Sorry we have had to delete your links. We get so many companies tring to post advertising links to their own websites for free that we have to ban pretty much all external links. Go to our DIY Projects pages and look at the condensation project. There is a company in there whoi will give you free, no obligation advice over the phone or by email.
All the products you suggested look like glorified holes in a wall, The first one looks the most hopeful in that it does not have moving parts. However, I don't think you should be under any illusions that if you have two holes on either side of your home and the wind is blowing against one side you will get draughts - cold ones at this time of year.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!