Humidity is public enemy No1 for furniture. It can cause pieces to warp and crack, and Hong Kong's relative humidity levels hover around 80 per cent.
The best way to prevent damage is to invest in a dehumidifier, especially if you are in areas close to the water or mountains, where mould can grow on walls overnight.
According to the American Society of Heating, Refrigerating and Air Conditioning Engineers' standard environmental conditions for human occupancy, it is recommended that relative humidity be kept between 30 and 50 per cent in summer, and 30 to 40 per cent in winter.
Dehumidifiers are usually sized by floor area and the level of dampness of the home. When choosing one, always round up in size, as larger units are more efficient and can deal with moisture more quickly. For a flat of 500 sq ft, choose a machine with a minimum moisture removal capacity of seven litres per day. For 1,000 sq ft this should rise to at least nine litres per day.
As far as looks go, systems have not changed in recent years and electrical companies have still not designed beyond the ugly, white boxy units.
A dehumidifier extracts moisture from the air using a refrigeration system. Water removed from the air is collected in a tank.
Most importantly, look for a model that will automatically switch off once the tank is full.
People have been known to forget to switch machines off only to return to a flood of water on the floor. In some models water can be removed automatically through a hose connected to the drain in the kitchen or bathroom.
Humidity levels can be adjusted with a humidistat. This feature will automatically turn the unit on or off depending on the humidity setting.
If you're looking to move the unit from room to room, look for one that is compact, lightweight, and includes a carry handle or rolling casters.
If the unit has an air vent on top, it can be placed against the wall. If it doesn't it will need to be placed away from walls and furniture for proper circulation.
It's best to place a dehumidifier in a room that is cooled via an air conditioner. The forced air system will circulate air to and from the dehumidifier to help control humidity throughout the home.
If there is a specific room with a moisture problem, such as one facing a mountain, it is usually more effective to locate the unit there.
Most dehumidifiers require little maintenance, other than keeping the air filter clean and checking that the settings are what they are expected to be. Since a dirty air filter can dramatically increase operating costs and reduce moisture removal rates, the filter should be checked once a month.
Dust from the coils should also be removed with a soft brush.