No. Condensation only occurs where humid air meets a cold surface, allowing water to condense.
The proximity of blinds to the glass will not cause condensation to occur – the conditions must pre-exist for this to happen but, in some circumstances, they might act as a barrier which could limit air-flow and so take longer for the condensation to evaporate.
Condensation is common in newly built conservatories where there is still a great deal of moisture still in the fabric of the building, from all of the concrete and plaster. It can take weeks for this to completely dry out – sometimes longer if the weather is very cold and/or wet.
The only real ‘cure’ for long-term condensation is to create adequate ventilation for the cold moist air (open the trickle vents at the heads of the windows and doors) and to improve the heating and air flow. This is something that should have been considered at the design stage of the conservatory.
For a short-term solution you can hire a dehumidifier (but be careful not to dry out the structure too quickly) or you can even buy large silica-gel cushions (normally meant for cars) that will help to absorb moisture from the air, but that is just dealing with the symptoms – not necessarily the cause.
Condensation is also more likely to occur when your conservatory is isolated from the rest of your home by external doors, or where there are lots of people in the room. Small conservatories tend to suffer more than average sized conservatories, because there is only a small volume of air which can quickly reach “dew point” (where there is so much humidity that it can condense).
Recessed window blinds are fitted so close to the glass that the fabric can come into contact with any condensation. If your window is dirty, then this would form a suitable organic material for bacteria to thrive and grow as mould.
You must therefore ensure that your blinds are kept clean because, by the time that mould has started to appear, it is almost certainly too late to clean the fabric and it will require replacing.
If your conservatory suffers from condensation:
Delay installation of blinds in a newly built conservatory until it is dry
Consider hiring a dehumidifier
Improve ventilation and air flow throughout the conservatory
Increase the heating and flow of warm air
Avoid any ‘cold spots’ from being created
Keep your glass clean, but avoid any aggressive chemicals
Make sure that your blinds are kept clean at all times
Keep blinds retracted when you know condensation is forming
Check for a small concealed leak or water ingress by capillary action
In serious cases, take your blinds down to stop them from becoming damaged