Following the rules outlined below will enhance the performance of your DVS ventilation system. They are explained more fully in individual one-page fact sheets available on request by calling 0800 387 387, and in the Operating Guidelines supplied with every DVS system.

Maintain adequate heating, especially on colder nights.

According to BRANZ research both continuous ventilation and adequate heating are needed to reduce excess moisture in homes. If indoor temperatures are not maintained at reasonable levels (the World Health Organisation recommends above 18 degrees Celsius), normal levels of moisture inside the home will cool and result in condensation - even in homes which are well-ventilated.

Note also, that the DVS system ventilates your home with a continuous supply of drier air and, during winter, this air is usually cooler. Therefore, it may be necessary to use more heating, or change the times of day your home is heated, during colder weather. Remember, though, that less energy is required to heat dry air than damp air. Any additional heating required in colder months is usually offset by much less heating being required during other times of the year.

Avoid using unflued, LPG and bottled gas heaters in your home.

Unflued, LPG and bottled gas heaters release massive quantities of water vapour into your home - therefore, they may reduce the effectiveness of the DVS system, preventing it from achieving its highest level of condensation control. They also produce toxic by-products which can harm your health. Consequently, we strongly advise against using these heaters in your home.

Keep internal doors OPEN, not just slightly ajar.

Closing internal doors prevents the drier, fresher air circulated by the DVS from entering those rooms. Therefore, doors should therefore be kept at least half open - not just slightly ajar. Additional outlets can be installed in rooms where you would prefer to close the doors at night.

Keep external doors and windows CLOSED, especially during colder weather. 

Opening external doors and windows will cause air from the DVS to channel straight out of your home through the open door or window, preventing the DVS system from slightly pressurising your home. Similarly, other openings, such as open fireplaces, should be closed when practicable.

Make sure adequate airflow can reach window surfaces.

Where windows are ‘closed off’ from a room by pelmets, roman blinds or heavy ceiling-to-floor curtains, it is difficult for air from the DVS to reach the windows and effectively control condensation. In main living areas, open curtains slightly (you may need to experiment with the size of the opening) when you go to bed at night; in bedrooms, pull curtains or blinds out from the wall at the bottom or sides to allow some air to reach the windows.