Re: Vents
My dad (RIP) spent most of his working life as a TV/VCR engineer back in the days when many people rented such devices (especially VCRs) and they would be repaired in your front room (on site in today's terminology).
The worst was being called to non-working VCRs. Customer would claim "it just stopped working" usually with a tape inside. My dad lifted up the VCR to have look through the front loading slot and out poured pungent yellow liquid...
"Dog must have p*ssed on it"...
A rapid exit and change of clothing was usually required.