Was in my local Do-it-All (Home Depot) store at the end of the day to pick up some bits for home.

Saw on a shelf a little box about 12" (300mm) high x 6" (150mm) wide x 5" (125mm) deep which contained a Dehumidifier operated by a Peltier device. It was priced around 20GBP.

Powered from the 230vac mains through a 9vdc transformer, so it could run, briefly off a 9v battery if you got desparate

The duty was claimed to be 250ml at 30°C 80%RH.

I think it was suggested for use in a clothes wardrobe. Just wonder what the duty will be in our northern climes at this time of the year