I would appreciate advice on diverting an extractor duct which is going to be blocked by a new conservatory roof due to be installed shortly.
The conservatory people want to divert the ducting up 6 brick courses within the cavity but I’m concerned that this may lead to condensation in the duct running back into the kitchen. Conversely, lowering the duct would allow any condensation to run off but may lead to back pressure as hot air is inclined to rise.
Which is the least worst option ?