Sub Floor Ventilation: Cost Considerations

image_3Sub floor ventilation offers an excellent solution to mould and rising damp due to moisture in house floors. Inadequate floor ventilation in your home can lead to problems like mould, rotting and structural weakness. With a well-installed ventilation system, damp air can be extracted from your floor space and replaced with fresh air, making sure your home is healthy.

The mechanism basically makes use of the fan system, where the fan aids in pushing damp and moist air from your sub floor. When the fan is operated non-stop for about 4 hours per day, it’s sufficient to ensure that good ventilation is maintained during the entire day. It’s best to have it running during the day when the air is dry and warm.

Sub Floor Ventilation Cost Factors

The Building Code of Australia (BCA) Vol. 2 points out that to avert the deterioration of sub floors (especially those made of timber), adequate ventilation should be inbuilt into your house sub-floor area. Typically, subfloor ventilation systems are energy efficient. However, you can estimate the cost of operating one annually by looking at the motor wattage.

The wattage of the motor will depend upon the following major factors:

  1. image_4The noise produced by the system is dependent on the size of the fan in use, whereby larger fans produce a lot of noise. This will mean high wattage and hence high cost of maintaining the fan. Smaller fans are more affordable and can be stored in unused rooms or even special cupboards. A large fan can only be installed outside, meaning higher costs for a structure to shelter it from invaders and bad weather conditions.
  1. The type of power running the system is another factor. Solar-powered fans are better because the natural energy is cheap. The initial cost, though, would be higher since a solar panel is required; but it becomes more effective later on as fewer costs would be incurred in running and maintenance. However, solar units have much lower capacities; and, where a battery is not available, they can only run while the sun is shining.
  1. The size of the system required for your sub floor area is also a very important consideration as it will also affect its cost. You would need to measure the required space in m3.
  1. If the problem to be corrected by your system is more intense, it will mean that the system has to run for longer hours than the recommended 4 hours per day. For example, if the problem being addressed is an already affected sub floor made of timber, more energy would be used and the cost of running such a system would be high. However, this is not always the case and it’s only in very cold environments that such cases are present. The Australian Timber Flooring Association addresses the issue of installing sub floor ventilation for timber flooring.
  1. It’s recommended that air be expelled by exhausting it from under your house and not by pushing it in. This is because when air is pushed in, it sometimes finds its way into the house through floor gaps, vents and also under doors. When exhausted through a ducted system, all the air will be expelled properly and will ensure efficiency and maximum effectiveness of the system.