Hi folks
Sorry to intervene, late on, in this somewhat heated discussion between folks whose separate opinions I have, in my short time on this site grown to respect.
I'm a Brit, with over 40 years experience as a Chemical Engineer in the Oil, Gas & Petrochemical industries.
Setting the academics of the OED (and Brazilian English, as Peter123 requested) aside for one moment:
The distinction that I, as a Brit Engineer, would have drawn between a drier and a dehumidifier is that I would normally expect a dehumidifier to recover the humidity as a liquid, whereas a simple drier would merely drive off the moisture and exhaust it to atmosphere.
Getting back to the original question, I don't believe there is a short form for dehumidifier itself. I am, however, currently resident in the Arabian Gulf and, not very far away from me, I have a device that either cools or dehumidifies the air in the room. It's called an Air Conditioner - and that does have a short form - A/C.
That having been said, I think I'll take StuartNZ's advice and translate myself to the bar, where I'll pick up a cool, refreshing (albeit diet) Pepsi/Coke!
Regards to you both!

peter123
Re: dehumidifier
Hi there,
Look for answers ONLY from native English speakers.
Would there be a short term for 'dehumidifier' in conversation? It seems that 'dehumidifier' is a bit long?
Thanks
pete